PT2E-3512

Gas Detector with Signal Converter
SD-3 Series
Export specifications

Technical Manual（PT2-287）

Contents

Contents
1.

2.

3.

4.

Product Overview ................................................................................................................................................. 5
1-1 Introduction ................................................................................................................................................... 5
1-2 Intended use and features............................................................................................................................ 7
1-2-1 Models and Codes ............................................................................................................................ 7
1-2-2 Detection principles and detection target gases for individual models ............................................ 8
1-2-3 Product features ................................................................................................................................ 9
1-3 Usage zones and conditions ...................................................................................................................... 10
1-4 DANGER, WARNING, and NOTE ............................................................................................................. 11
1-5 Method of confirmation for Standards and Explosion proof specification ................................................. 11
Important Safety Information .............................................................................................................................. 12
2-1 Danger information ..................................................................................................................................... 12
2-2 Warning information.................................................................................................................................... 12
2-3 Caution information..................................................................................................................................... 13
2-4 Safety information ....................................................................................................................................... 14
Product Configuration......................................................................................................................................... 31
3-1 Main unit and accessories .......................................................................................................................... 31
3-1-1 Main unit (SD-3) .............................................................................................................................. 31
3-1-2 Main unit (SD-3SC) ......................................................................................................................... 32
3-1-3 Remote sensor head (GD-3) .......................................................................................................... 32
3-1-4 Standard accessories ..................................................................................................................... 33
3-1-5 Optional accessories....................................................................................................................... 34
3-2 Part names and functions........................................................................................................................... 38
3-3 Block diagrams ........................................................................................................................................... 39
Installation ........................................................................................................................................................... 41
4-1 Installation precautions ............................................................................................................................... 41
4-1-1 General installation information ...................................................................................................... 41
4-1-2 Restrictions regarding installation ................................................................................................... 42
4-2 System design precautions ........................................................................................................................ 47
4-2-1 Using a stable power supply ........................................................................................................... 47
4-2-2 Lightning strike protective measures .............................................................................................. 47
4-3 Providing maintenance space .................................................................................................................... 48
4-4 Main unit installation ................................................................................................................................... 50
4-4-1 Vertical pole mounting..................................................................................................................... 50
4-4-2 Wall mounting.................................................................................................................................. 51
4-4-3 Attaching protective cover............................................................................................................... 52
4-4-4 Attaching sunshade cover .............................................................................................................. 54
4-5 Remote sensor head (GD-3) installation ................................................................................................... 56
4-5-1 Wall mounting.................................................................................................................................. 56
4-5-2 Duct mounting ................................................................................................................................. 56
4-6 Connecting the grounding terminal ............................................................................................................ 58
4-7 Connecting the power and signal cables ................................................................................................... 59
4-7-1 Main unit cable and device connectors .......................................................................................... 59
4-7-2 Connecting the power and signal cables to the main unit ............................................................. 61
4-7-3 Connecting the power and signal cables to the remote sensor head (GD-3) ........................................ 64
4-7-4 Connecting the main unit (SD-3SC) and remote sensor head (GD-3).......................................... 67
4-7-5 Connecting cables to the terminal plate ......................................................................................... 72
4-8 Mounting the sensor ................................................................................................................................... 75
4-9 Alarm relay setting (option)......................................................................................................................... 76
4-10 Mounting the splash guard ....................................................................................................................... 79

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Contents

5.

6.

7.

4-11 How to install the lightning arrester .......................................................................................................... 80
Usage Instructions .............................................................................................................................................. 81
5-1 Preparations for startup .............................................................................................................................. 81
5-2 Startup......................................................................................................................................................... 82
5-3 Basic operation flow.................................................................................................................................... 83
5-4 Operating procedure................................................................................................................................... 84
5-5 User mode .................................................................................................................................................. 85
5-5-1 User mode setting items ................................................................................................................. 85
5-5-2 Switching to user mode .................................................................................................................. 86
5-6 Performing zero calibration......................................................................................................................... 87
5-7 Checking settings ....................................................................................................................................... 89
5-7-1 Checking alarm setpoints ............................................................................................................... 89
5-8 Shutting down ............................................................................................................................................. 91
Alarm Activation .................................................................................................................................................. 92
6-1 Gas alarm activation ................................................................................................................................... 92
6-1-1 Alarm activation............................................................................................................................... 92
6-1-2 Contact operation (auto reset) ........................................................................................................ 93
6-1-3 Contact operation (self-latching) ..................................................................................................... 94
6-1-4 Alarm response ............................................................................................................................... 97
6-2 Fault alarm activation.................................................................................................................................. 97
6-3 Warning operation ...................................................................................................................................... 98
6-4 External output operation ........................................................................................................................... 99
6-4-1 For target gases other than oxygen ............................................................................................... 99
6-4-2 When the target gas is oxygen ..................................................................................................... 103
6-5 Functions to ensure correct alarm activation ........................................................................................... 106
6-5-1 Zero suppression function ............................................................................................................ 106
6-5-2 Automatic sensor recognition function ......................................................................................... 107
Maintenance ..................................................................................................................................................... 108
7-1 Maintenance intervals and items.............................................................................................................. 108
7-2 Maintenance mode ................................................................................................................................... 110
7-2-1 Maintenance mode setting items.................................................................................................. 110
7-2-2 Switching to maintenance mode ...................................................................................................111
7-3 Performing tests (test mode) .................................................................................................................... 113
7-3-1 Performing gas test ....................................................................................................................... 113
7-3-2 Performing alarm test.................................................................................................................... 114
7-3-3 Performing fault test ...................................................................................................................... 116
7-3-4 Performing LED test...................................................................................................................... 117
7-3-5 Performing memory test (RAM test) ............................................................................................. 118
7-4 Performing calibration............................................................................................................................... 119
7-4-1 Calibration preparation.................................................................................................................. 119
7-4-2 Performing zero calibration ........................................................................................................... 125
7-4-3 Performing span adjustment......................................................................................................... 126
7-5 Setting environmental settings 1 .............................................................................................................. 130
7-5-1 Inhibit setting ................................................................................................................................. 130
7-5-2 Alarm setpoint setting.................................................................................................................... 131
7-5-3 Zero suppression value setting..................................................................................................... 132
7-5-4 Zero suppression type setting....................................................................................................... 133
7-5-5 Password setting ........................................................................................................................... 134
7-5-6 Date and time setting .................................................................................................................... 135
7-6 Setting environmental settings 3 .............................................................................................................. 136
7-6-1 Double range external output setting

NC .............................................................................. 137

7-7 Parts replacement..................................................................................................................................... 138
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Contents

7-7-1 Sensor replacement ...................................................................................................................... 138
7-7-2 Replacement of periodic replacement parts................................................................................. 139
8.
Storage, Relocation, and Disposal................................................................................................................... 140
8-1 Procedures for storage or when not in use for extended periods ........................................................... 140
8-2 Procedures for relocation or reuse ........................................................................................................... 142
8-3 Product disposal ....................................................................................................................................... 142
9.
Troubleshooting ................................................................................................................................................ 144
9-1 Product abnormalities ............................................................................................................................... 144
9-2 Reading abnormalities .............................................................................................................................. 145
10. Product Specifications ...................................................................................................................................... 147
10-1 SD-3 specifications ................................................................................................................................. 147
10-1-1 SD-3 (model without EC barrier) ................................................................................................ 147
10-1-2 SD-3 (model with EC barrier) ..................................................................................................... 150
10-1-3 Electrical ratings (SD-3) .............................................................................................................. 153
10-2 SD-3SC + GD-3 specifications............................................................................................................... 154
10-2-1 SD-3SC + GD-3 (model without EC barrier) .............................................................................. 154
10-2-2 SD-3SC + GD-3 (model with EC barrier) ................................................................................... 157
10-2-3 Electrical ratings (SD-3SC + GD-3) ............................................................................................ 160
10-3 Detection target gases for individual detection principles...................................................................... 161
10-3-1 Non-dispersive infrared absorption type (Infrared type)............................................................. 161
10-3-2 New ceramic type (catalytic type) ............................................................................................... 162
10-3-3 Semiconductor type .................................................................................................................... 163
10-3-4 Hot-wire semiconductor type ...................................................................................................... 165
10-3-5 Electrochemical type ................................................................................................................... 167
11. Appendix ........................................................................................................................................................... 168
11-1 Detection principle .................................................................................................................................. 168
11-1-1 Non-dispersive infrared absorption type (Infrared type) ............................................................. 168
11-1-2 New ceramic type (catalytic type) ............................................................................................... 169
11-1-3 Semiconductor type .................................................................................................................... 170
11-1-4 Hot-wire semiconductor type ...................................................................................................... 171
11-1-5 Electrochemical type ................................................................................................................... 172
11-2 Terminology ............................................................................................................................................. 173
Product warranty .............................................................................................................................................. 174
Sensor warranty ............................................................................................................................................. 174
Revision History................................................................................................................................................ 175

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1. Product Overview

1-1 Introduction

1

Product Overview
1-1 Introduction
Thank you for purchasing the SD-3 Gas Detector with Signal Converter (“product” hereinafter).
This operating manual describes product operating procedures and specifications. It provides information
essential to correct use of the product.
Make sure you have read and fully understood the contents of this manual before using the product.
Keep this operating manual on hand to allow ready reference during use.
The contents of this manual are subject to change without notice to allow product improvements. Any
duplication or reproduction of this manual without permission is prohibited, whether in whole or in part.
RIKEN KEIKI accepts no liability for accidents or damage resulting from use of the product, whether within or
outside the warranty period.
Be sure to read the warranty policy at the end of this document.
Before using the product, please confirm that the model of the product you purchased matches the model of the
product covered by this operating manual.

<Models covered by this operating manual>

Main unit

Main unit

Remotesensor head

Diffusion typeSD-3RI
SD-3NC
SD-3GH
SD-3GHS
SD-3SP
SD-3EC
SD-3ECS
SD-3ECB
SD-3SCGD-3RI
GD-3NCGD-3GH
GD-3GHS
GD-3SP
GD-3ECGD-3ECS
GD-3ECB

Suction typeSD-3DRI
SD-3DNC
SD-3DGH
SD-3DGHS
SD-3DSP
SD-3DEC
SD-3DECS
SD-3DECB

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1. Product Overview

1-1 Introduction<This operating manual>In this operating manual, where descriptions differ according to the detection principle, these are indicated by
the following icons:
Non-dispersive infrared absorption type(infrared type)

RI

New ceramic type (catalytic type)NC

Semiconductor typeGH

Hot-wire semiconductor type

SP

Electrochemical typeEC

Operating procedures and specifications for which no icons appear apply to all detection principles.
The display examples provided in this operating manual apply when the detection target gas is combustible(display units: %LEL).

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1. Product Overview

1-2 Intended use and features

1-2 Intended use and features
The product is a fixed explosion-proof device for continuous monitoring of combustible gases, toxic gases, andoxygen in the air.
An alarm is triggered if combustible gases, toxic gases, or oxygen exceeding preset concentrations aredetected in the air.
The detection results are not intended to assure life or safety.

1-2-1 Models and Codes
SD-3

①

②

（ ③

④

⑤

⑥

⑦

⑧ ）

[Remote type: Main unit (SD-3SC) + Remote sensor unit (GD-3)]
SD-3SC （ ③
④
⑤
⑥
⑦
⑧ ）
GD-3 ②
①

②

③

④

⑤

Diffusion type/suction type selection
Blank Diffusion typeD
Suction type (introduced via external unit)
Sensor type selection
RI
Infrared typeNC
New ceramic type (catalytic type)GH
Semiconductor typeGHS Semiconductor type (for CS2)
SP
Hot-wire semiconductor type
EC
Electrochemical type (for CO/O2)
ECS Electrochemical type (for H2S)Electrochemical type (other thanECB
CO/O2/H2S)
Cable connectors
0Connector 1 + Connector 2Connector 1 + Connector 2+ Connector
1
4 + Connector 5
Explosion-proof
1
ATEX/IECEx/UKEX
2
FM (US)
3
Japan Ex4cFM (CANADA)
Functional safety IEC61508*1
0None1
SIL (for RI/NC/EC/ECS/ECB)

⑥

⑦

⑧

Performance certification
0
None
1
ATEX
2
US
3
CANADA
4
JIS
Range setting*20Single range
1
Double range +4-16 (for NC)
2
Double range + L4-20 (for NC)
3
Double range + H4-20 (for NC)
Output type selection0
1

4-20 mA + HART
4-20 mA + HART + contact (3c)2-*1 W range is not supported in the SIL specification.
*2 HART communication is unavailable when double range(optional) is selected.

Connector
3*Not used

Connector
2

Connector
4Standard

Optional

Connector
1

Connector
5Standard

Optional
Example: Cable connectors

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1. Product Overview

1-2 Intended use and features

1-2-2 Detection principles and detection target gases for individual models
The product is available in the following models, depending on the specific detection method and detection
principle.
Check the specifications before use to confirm that correct gases will be detected in accordance with theintended purpose.
<List of detection target gases by model>
Main unit
model

Detection
methodDetection principle
Non-dispersive infraredabsorption type(infrared type)New ceramic type(catalytic type)SD-3RI
SD-3NC
SD-3GH
SD-3GHS

Detection target gas
Toxic
gas

〇

〇

OxygenRemarks〇

Semiconductor type
Diffusion

Combustible gas〇

Semiconductor type〇
CS2 (carbon disulfide) only〇

SD-3SP

Hot-wire semiconductor
type

SD-3ECElectrochemical type〇

SD-3ECS

Electrochemical type〇

H2S (hydrogen sulfide)only

SD-3ECBElectrochemical type〇

With EC barrier*Non-dispersive infraredabsorption type(infrared type)New ceramic type(catalytic type)SD-3DRI
SD-3DNC
SD-3DGH
SD-3DGHS

〇

〇
〇

〇

〇

Semiconductor type
Suction〇〇Semiconductor type〇
CS2 (carbon disulfide) only〇

SD-3DSP

Hot-wire semiconductor
type

SD-3DEC

Electrochemical type〇SD-3DECSElectrochemical type〇

H2S (hydrogen sulfide)only

SD-3DECB

Electrochemical type〇

With EC barrier*〇*Differs depending on detection target gas.

8 / 175〇〇

1. Product Overview

1-2 Intended use and features<List of detection target gases by model (remote sensor type)>
Main unit model

SD-3SC

Remotesensor headmodel

Detection
methodNon-dispersive infraredabsorption type(infrared type)New ceramic type(catalytic type)

GD-3RI
GD-3NCGD-3GH
GD-3GHS

Detection principle

Detection target gas
Combus- Toxic
Oxygentible gas
gas

Semiconductor type
Diffusion〇

Remarks〇〇〇

Semiconductor type〇
CS2 (carbon disulfide)only〇

GD-3SP

Hot-wire semiconductor
type

GD-3ECElectrochemical type〇

GD-3ECS

Electrochemical type〇

H2S (hydrogen sulfide)
only

GD-3ECBElectrochemical type〇

With EC barrier*〇〇〇*Differs depending on detection target gas.

<Sensor models and detection principles>
Sensor model

Detection principle

IRF

Infrared typeNCF

New ceramic type (catalytic type)

SGF

Semiconductor type

SHF

Hot-wire semiconductor type

ESF

Electrochemical type1-2-3 Product features<Standard specifications> The product is constructed with a stainless steel housing suitable for both indoors and outdoors use.
 Requires a 24 V DC (DC 18 V to 30 V) power supply.
 The gas concentration, status, and command selection menu are displayed using seven-segment LEDs.
 The concentration of the gas detected is converted to a 4 - 20 mA analog output (NAMUR NE43 compliant)or a digital HART output signal.
 It can be connected to a RIKEN KEIKI monitoring system or programmable logic controller (PLC) via a ceiling
fitting or approved cable gland.

<Optional specifications> The product can be operated as a standalone unit by setting an alarm relay. Using the product as astandalone unit allows control of devices without the need for a central controller.*1*1: Using the product as a standalone unit requires additional alarm signal settings.

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1. Product Overview

1-3 Usage zones and conditions

1-3 Usage zones and conditions
The product is approved for use in areas where gases classified in explosive gas groups IIA, IIB, or IIC may bepresent. This refers to use limited to hazardous zones categorized as Zone 1 or Zone 2 within the productoperating temperature range.

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1. Product Overview

1-4 DANGER, WARNING, and NOTE

1-4 DANGER, WARNING, and NOTEThis operating manual uses the following categories to indicate potential damage/hazards if the user disregards
the information provided and uses the product incorrectly:

DANGER

This indicates situations in which improper handling may result in fatal or
serious injury or significant property damage.

WARNING

This indicates situations in which improper handling may result in serious injury
or significant property damage.

CAUTION

This indicates situations in which improper handling may result in minor injury
or minor property damage.

Additionally, usage recommendations are indicated as follows:

NOTE

This indicates items that will be helpful to know when using the product.

1-5 Method of confirmation for Standards and Explosion proof
specification
This instrument has some specification depends on standard and explosion proof certificate. Please confirm thedetector specification before using. Please refer Declaration of Conformity that is at the end of this manual if you
have CE/UKCA marking type. You can confirm instrument specification to see name plate as follows.

< SD-3 >ATEX/IECEx/UKEX
CE/UKCA marking type name plate

CE marking< GD-3 >UKCA marking

11 / 1752. Important Safety Information

2-1 Danger information

2

Important Safety
Information
2-1 Danger information
DANGER
 Do not open the cover while the power is turned on. When opening the cover, use a portable gas
detector or other similar device to confirm that there is no gas present in the vicinity.
 Do not attempt to repair the product.
 Do not attempt to repair or replace the explosion-proof bonding surface. If you observe scratches, cracks,
or deformation on the housing or explosion-proof bonding surface, stop using the product immediately
and contact RIKEN KEIKI promptly.

2-2 Warning information
WARNING Before turning on the power for the product, be sure to confirm that the power source meets the specified
voltage requirements.
Using power supplies other than the stipulated voltage will damage the product. Do not use unstable
power supplies. Doing so may result in malfunctions.
 Do not disconnect the protective grounding wire or terminal.
 Before operating the product, check the protective functions for defects.
Do not operate the product if you suspect any problems with the protective grounding or other protectivefunctions.
 Connect to a protective ground before connecting to external control circuits.
 Before adjusting zero for the surrounding atmosphere, confirm that the surrounding atmosphere contains
clean air.
The presence of interference gases will prevent proper air calibration. The presence of miscellaneous
gases is also extremely dangerous because the product may not detect actual gas leaks correctly.
 A gas alarm indicates the presence of extreme danger. The user must take appropriate action after taking
suitable steps to ensure safety.
 Do not immerse the product in organic solvents for extended periods. The flame arrester components are
made of polyphenylene sulfide (PPS) resin.

12 / 1752. Important Safety Information

2-3 Caution information

2-3 Caution information
CAUTION The product operation may be affected by radio waves emitted from walkie-talkies or other radiotransmitters used near the product or its cables. Position walkie-talkies or other similar devices so thatthey do not affect the product operation.
 Wait at least 10 seconds before turning the power back on again after turning off. The product may not
function correctly if the power is turned back on immediately.
 The product is not a control device. Never use the product output to control other devices.
 Do not disassemble or alter the product. Product performance cannot be guaranteed if the product isdisassembled or modified.
 Do not alter settings unnecessarily unless you are fully aware of the consequences. Doing so may resultin improper alarm function. Avoid performing any operations not described in this operating manual.
 The product is a safety device. Be sure to maintain the product at regular intervals to ensure safety.
Continuing to use the product without adequate maintenance will result in sensor sensitivity degradationand prevent proper gas detection.

13 / 1752. Important Safety Information

2-4 Safety information

2-4 Safety information<Product overview> The products have an explosion-proof construction.
 Sensors are divided into three different types, depending on the corresponding detection principles. The
detection methods are divided into the diffusion type and suction type. Suction-type sensors should be usedwith a suction cap fitted.
 The product is a fixed, continuous monitoring detector. It can be connected to a gas monitoring control unit,
recorder, or programmable control unit to output the measured gas readings as a 4 - 20 mA signal or HART
signal.
 The following three sets of output specifications are available for this product:
・ No alarm relay, no digital communication
・ 3 alarm relays (contact output) (alarm relays operate in conjunction with gas alarms and faults), no
digital signal
・ No alarm relay, digital communication (RS-485 output) The electrochemical sensor is made into an explosion-proof construction by using an EC barrier.

<Detection principles and models> The models corresponding to the individual detection principles are as follows. The models are classified bydetection principle and detection method.
Detection principle (Detection method: Diffusion type)

Model

Optical sensor

Non-dispersive infrared absorption type (infraredtype)

SD-3RI

Solid state sensor

Semiconductor typeSD-3GH
SD-3GHSElectrochemical sensor

New ceramic type (catalytic type)

SD-3NC

Hot-wire semiconductor type

SD-3SPElectrochemical type

SD-3EC
SD-3ECS
SD-3ECB

Detection principle (Detection method: Suction type)

Model

Optical sensor

Non-dispersive infrared absorption type (infraredtype)

SD-3DRI

Solid state sensor

Semiconductor typeSD-3DGH
SD-3DGHS

Electrochemical sensor

New ceramic type (catalytic type)SD-3DNC

Hot-wire semiconductor typeSD-3DSPElectrochemical typeSD-3DEC
SD-3DECS
SD-3DECB

14 / 1752. Important Safety Information

2-4 Safety information

 The SD-3SC is used with a remote sensor head (GD-3) from among the following models:Model
Detection principle (Detection method: Diffusion type)
GD-3(Remote sensor head)
Optical sensor
Non-dispersive infrared absorption
GD-3RI
type (infrared type)
Solid state sensor
Semiconductor type
GD-3GH
GD-3GHSNew ceramic type (catalytic type)
GD-3NC
Hot-wire semiconductor type
GD-3SPElectrochemical sensor Electrochemical type
GD-3ECGD-3ECS
GD-3ECB

SD-3

SD-3SCWARNING The SD-3EC and GD-3EC models are subdivided by the type of explosion-proof construction of theflame arrester fitted to the sensor and whether they include an EC barrier.
The expected explosion-proof performance cannot be ensured if the incorrect flame arrestor is used. Do
not replace with a different flame arrester.
 The SD-3GH and GD-3GH models are subdivided by the type of explosion-proof construction of theflame arrester fitted to the sensor.
The expected explosion-proof performance cannot be ensured if the incorrect flame arrestor is used. Do
not replace with a different flame arrester.

15 / 1752. Important Safety Information

2-4 Safety information<Explosion-proof performance data>
The range of ambient temperatures in which explosion-proof performance can be maintained will differ dependingon whether the optional lightning arrester is fitted.
Refer to the following performance data for each model:<Without lightning arrester>
Explosionproof
construction

Group

Category

Explosion-proof
class

EPL

Ambient temperature*1

d

II

2G

Ex db IIC T6/T5

Gb-50 °C ≤ Ta ≤ +60 °C /+70 °C

d

II

2G

Ex db IIC T5/T4

Gb-50 °C ≤ Ta ≤ +44 °C /+70 °C

d

II

2G

Ex db IIC T6/T4

Gb-50 °C ≤ Ta ≤ +47 °C /+70 °C

d

II

2G

Ex db IIC T5/T4

Gb-50 °C ≤ Ta ≤ +44 °C /+70 °C

d

II

2G

Ex db IIC T5/T4

Gb-50 °C ≤ Ta ≤ +55 °C /+70 °C

d

II

2G

Ex db IIC T4

Gb-50 °C ≤ Ta ≤ +70 °C

d

II

2G

Ex db IIC T4

Gb-50 °C ≤ Ta ≤ +70 °C

d+i

II

2G

Ex db ia IIC T4

Gb-40 °C ≤ Ta ≤ +70 °C

SD-3SC*2

d

II

2G

Ex db IIC T6/T5/T4

Gb-50 °C ≤ Ta ≤ +47 °C /+55 °C+70 °C

SD-3SC*3

d

II

2G

Ex db IIC T5/T4

Gb-50 °C ≤ Ta ≤ +44 °C /+70 °C

SD-3SC*4

d

II

2G

Ex db IIC T6/T5

Gb-50 °C ≤ Ta ≤ +60 °C /+70 °C

SD-3SC*5

d

II

2G

Ex db IIC T4

Gb-40 °C ≤ Ta ≤ +70 °C

Model

SD-3RI
SD-3DRI
GD-3RI
SD-3GH
SD-3DGH
GD-3GH
SD-3GHS
SD-3DGHS
GD-3GHS
SD-3NC
SD-3DNC
GD-3NC
SD-3SP
SD-3DSP
GD-3SP
SD-3EC
SD-3DEC
GD-3EC
SD-3ECS
SD-3DECS
GD-3ECS
SD-3ECB
SD-3DECB
GD-3ECB*1: The ambient temperature refers to temperatures in the range within which explosion-proof performance can be
maintained. It does not imply the temperature range within which the required product performance may beachieved. For information on the operating temperature range, refer to ‘10-3 Detection target gases for individual
deterction principles’.
*2: When used in combination with GD-3GHS, GD-3SP, GD-3EC, and GD-3ECS*3: When used in combination with GD-3GH and GD-3NC*4: When used with the GD-3RI*5: When used in combination with GF-3ECB

16 / 1752. Important Safety Information

2-4 Safety information<With lightning arrester>
Explosionproof
construction

Group

Category

Explosion-proof
class

EPL

Ambient temperature*1

d

II

2G

Ex db IIC T6/T5

Gb-40 °C ≤ Ta ≤ +60 °C/+70 °C

d

II

2G

Ex db IIC T5/T4

Gb-40 °C ≤ Ta ≤ +44 °C /+70°C

d

II

2G

Ex db IIC T6/T4

Gb-40 °C ≤ Ta ≤ +47 °C /+70°C

d

II

2G

Ex db IIC T5/T4

Gb-40 °C ≤ Ta ≤ +44 °C /+70 °C

d

II

2G

Ex db IIC T5/T4

Gb-40 °C ≤ Ta ≤ +55 °C /+70 °C

d

II

2G

Ex db IIC T4

Gb-40 °C ≤ Ta ≤ +70 °C

d

II

2G

Ex db IIC T4

Gb-40 °C ≤ Ta ≤ +70 °C

d+i

II

2G

Ex db ia IIC T4

Gb-40 °C ≤ Ta ≤ +70 °C

SD-3SC*2

d

II

2G

Ex db IIC
T6/T5/T4Gb-40 °C ≤ Ta ≤ +47 °C /+55 °C+70 °C

SD-3SC*3

d

II

2G

Ex db IIC T5/T4

Gb-40 °C ≤ Ta ≤ +44 °C /+70 °C

SD-3SC*4

d

II

2G

Ex db IIC T6/T5

Gb-40 °C ≤ Ta ≤ +60 °C /+70 °C

SD-3SC*5

d

II

2G

Ex db IIC T4

Gb-40 °C ≤ Ta ≤ +70 °C

Model

SD-3RI
SD-3DRI
GD-3RI
SD-3GH
SD-3DGH
GD-3GH
SD-3GHS
SD-3DGHS
GD-3GHS
SD-3NC
SD-3DNC
GD-3NC
SD-3SP
SD-3DSP
GD-3SP
SD-3EC
SD-3DEC
GD-3EC
SD-3ECS
SD-3DECS
GD-3ECS
SD-3ECB
SD-3DECB
GD-3ECB*1: The ambient temperature refers to temperatures in the range within which explosion-proof performance can be
maintained. It does not imply the temperature range within which the required product performance may beachieved. For information on the operating temperature range, refer to ‘10-3 Detection target gases for individual
deterction principles’.
*2: When used in combination with GD-3GHS, GD-3SP, GD-3EC, and GD-3ECS*3: When used in combination with GD-3GH and GD-3NC*4: When used with the GD-3RI*5: When used in combination with GF-3ECB

17 / 1752. Important Safety Information

2-4 Safety information<Electrical data>
Option (select one)
Model

Supply voltage

Powerconsumption

Signal output

No alarm relay/
No digitalcommunication

SD-3RI
SD-3DRI
GD-3RI
SD-3GH
SD-3DGH
GD-3GH
SD-3GHS
SD-3DGHS
GD-3GHS
SD-3NC
SD-3DNC
GD-3NC
SD-3SP
SD-3DSP
GD-3SP
SD-3EC
SD-3DEC
GD-3EC
SD-3ECS
SD-3DECS
GD-3ECS
SD-3ECB
SD-3DECB
GD-3ECB
SD-3SC

Alarm relay(contact output)/

DigitalResistance load

communication

only

24 V DC(18 V - 30 V
DC Max)

3.8 W Max0 - 22 mA + HART―

30 V DC, 1 A
250 V AC, 2 A

RS-485 output

1.2 W Max

―

―

―

―

24 V DC(18 V - 30 V
DC Max)

4.5 W Max0 - 22 mA + HART―

30 V DC, 1 A
250 V AC, 2 A

RS-485 output

2 W Max

―

―

―

―

24 V DC(18 V - 30 V
DC Max)

4.5 W Max0 - 22 mA + HART―

30 V DC, 1 A
250 V AC, 2 A

RS-485 output

2 W Max

―

―

―

―

24 V DC(18 V - 30 V
DC Max)

4.5 W Max0 - 22 mA + HART―

30 V DC, 1 A
250 V AC, 2 A

RS-485 output

2 W Max

―

―

―

―

24 V DC(18 V - 30 V
DC Max)

3.5 W Max0 - 22 mA + HART―

30 V DC, 1 A
250 V AC, 2 A

RS-485 output

1 W Max

―

―

―

―

24 V DC(18 V - 30 V
DC Max)

2.8 W Max0 - 22 mA + HART―

30 V DC, 1 A
250 V AC, 2 A

RS-485 output

1 W Max

―

―

―

―

24 V DC(18 V - 30 V
DC Max)

2.8 W Max0 - 22 mA + HART―

30 V DC, 1 A
250 V AC, 2 A

RS-485 output

1 W Max――――
RS-485 output

24 V DC(18 V - 30 V
DC Max)24 V DC(18 V - 30 V
DC Max)

3.1 W Max0 - 22 mA + HART―

30 V DC, 1 A
250 V AC, 2 A

1 W Max

―

―

―

―

5 W Max

0 - 22 mA + HART―

30 V DC, 1 A
250 V AC, 2 A

RS-485 output<Certificate numbers>
 IECEx PRE 20.0064 X
 Presafe 20 ATEX 69725 X
 DNV 22 UKEX 25924X* The “X” at the end of the certificate number indicates the following special operating conditions:・ The flameproof joints are not intended to be repaired.
・ Regarding ATEX specification, the measuring function according to Annex II paragraph 1.5.5 of the Directive
is not covered by this EU-type examination.
It shall comply with the requirements from the relevant European harmonized standards which provide
guidance on the performance of gas detection equipment and safety devices.
・ The measuring function according to schedule 1, paragraph 24 of the Regulation is not covered in this UKtype examination. It shall comply with the requirements from the relevant UK Designated Standards which
provide guidance on the performance of gas detection equipment.
・ The Equipment with glass window plate must only be placed in areas with low risk of mechanical danger(ref clause 26.4.2 in EN 60079-0).
・ The manufacturer’s instructions provides guidance for the user to minimize the risk from electrostatic
discharge. Maximum capacitance of 6 nF can occur.
・ If attached to a flameproof enclosure the surge protectors shall be provided with a high strength locking
compound on the mounting thread.
・ Refer to manual for ambient temperature.
18 / 1752. Important Safety Information

2-4 Safety information

・ The measuring function of the EUT is not covered by this type examination. It shall comply with therequirements from the relevant harmonized standards which provide guidance on the performance of gas
detection equipment and safety devices.
・ The client should not try to replace the batteries.

<Applicable standards>
 IEC 60079-0:2017
 IEC 60079-1:2014
 IEC 60079-11:2011
 EN IEC 60079-0:2018
 EN 60079-1:2014
 EN 60079-11:2012
 BS EN IEC 60079-0:2018
 BS EN 60079-1:2014
 BS EN 60079-11:2012
<Operating manual no.> PT2-287

2-7-6 Azusawa, Itabashi-ku, Tokyo, 174-8744, Japan
Phone:+81-3-3966-1113
Fax:+81-3-3558-9110
Email:
intdept@rikenkeiki.co.jp
Website:https://www.rikenkeiki.co.jp
19 / 1752. Important Safety Information

2-4 Safety information<System configuration diagrams>

Installation diagram
Hazardous area
(Zone 1)Non-hazardousarea

Gas detector (SD-3)
Display
POW(+)COM(−)
Sig(+)
Sig(−)

Signal cable

POW(+)COM(−)
Sig(+)
Sig(−)

Installation diagram
Hazardous area
(Zone 1)Non-hazardousarea

Gas detector (SD-3)
Display
POW(+)COM(−)
Sig(+)
Sig(−)

RLY

Signal cable

Signal cable

20 / 175

POW(+)COM(−)
Sig(+)
Sig(−)RLY

2. Important Safety Information

2-4 Safety information

Installation diagram
Hazardous area
(Zone 1)Non-hazardousarea

Gas detector (SD-3 (RS-485))
Display
POW(+)COM(−)
Sig(+)
Sig(−)

Signal cable

RS-485Signal cable

POW(+)COM(−)
Sig(+)
Sig(−)

RS-485

Installation diagram
Hazardous area
(Zone 1)Non-hazardousarea

Gas detector (SD-3SC)
Display

Remote sensor head
(GD-3)
POW(+)COM(−)
RS-485(Y)RS-485(Z)Signalcable

POW(+)COM(−)
Sig(+)
Sig(−)

Signal cable

POW(+)COM(−)
RS-485(Y)RS-485(Z)21 / 175

POW(+)COM(−)
Sig(+)
Sig(−)

2. Important Safety Information

2-4 Safety information

Installation
diagramHazardous area
(Zone 1)Non-hazardousarea

Gas detector (SD-3SC)
Display

Remote sensor head
(GD-3)
POW(+)COM(−)
RS-485(Y)RS-485(Z)Signalcable

POW(+)COM(−)
Sig(+)
Sig(−)

Signal cable

POW(+)RLY
COM(−)
RS-485(Y)RS-485(Z)Signal cable

POW(+)COM(−)
Sig(+)
Sig(−)

RLY

Installation diagram
Hazardous area
(Zone 1)Non-hazardousarea

Gas detector (SD-3SC)
Display
POW(+)COM(−)
Sig(+)
Sig(−)

Signal cable

Remote sensor head
(GD-3)
POW(+)COM(−)
RS-485(Y)RS-485(Z)Signalcable

RS-485
POW(+)COM(−)
RS-485(Y)RS-485(Z)POW(+)COM(−)
Sig(+)
Sig(−)

RS-485Signal cable

22 / 1752. Important Safety Information

2-4 Safety information

CAUTION Install the product in accordance with the required installation conditions.
 Do not disassemble, modify, or alter the product.
 Contact RIKEN KEIKI to request readjustment or parts replacement including calibration.
 Use cable lugs for grounding wire and bonding conductor connections. Make sure the bonding
conductors are not loose or twisted.
 Do not open the cover in locations where explosive gas may be present.
 The maximum pressure inside the gas channels and sensor is 10.13 kPa (gauge pressure).
 Be sure to connect the grounding terminal before turning on the power to the product.
 Make sure the grounding is Class D equivalent (grounding resistance less than 100 Ω).
 Use crimped terminals to connect the grounding wire to the grounding terminal inside the unit. Use acable with a cross section area of at least 4 mm2 to connect to the external grounding terminal.
 Use approved cable glands when installing.
 If the product is installed in a location where the ambient temperature exceeds 65 °C, use cables
designed for use at temperatures at least 5 °C above the maximum ambient temperature.
 Do not subject the window in the cover to strong forces or impact. Doing so may result in damage andimpaired explosion-proof performance. (The low risk of mechanical hazards has been confirmed in
testing [2 joules].) Do not use more than one adapter per connector.

CAUTION
With suction type
 Use with a flow rate of at least 0.4 L/min and not exceeding 1.5 L/min.

23 / 1752. Important Safety Information

2-4 Safety information<Connector screw thread types and sizes (SD-3/SD-3SC)>
Connector 3

Connector 2Connector 4

Connector 5

Connector 1

Connector 6<Standard>
Connector 1

Connector 2Connector 3

Connector 4

Connector 5

Connector 6

M25 × 1.5

M25 × 1.5―――

M25 × 1.5

 “―” indicates no connector is available.
 Connectors 1, 2, and 6 can be used as cable entry ports. Use Connector 6 if the main unit (SD-3SC) is
connected to the remote sensor head (GD-3) with a cable. Use approved cable glands when connecting the
remote sensor head (GD-3).
 Blank off unused connectors with blanking plugs.
 For more information on using individual connectors, refer to ‘4-7 Cable connection’.
<Optional>
Connectors 4 and 5 are available with optional screw threads, as follows:
Connector 1

Connector 2Connector 3

Connector 4

Connector 5

Connector 6

M25 × 1.5

M25 × 1.5―

M25 × 1.5

M25 × 1.5

M25 × 1.5

 “―” indicates no connector is available.
 Connectors 1, 2, 4, and 6 can be used as cable entry ports. Use Connector 6 if the main unit (SD-3SC) is
connected to the remote sensor head (GD-3) with a cable. Use approved cable glands when connecting the
remote sensor head (GD-3).
 Up to two external cable connectors can be used at the same time. (Excluding the remote sensor head
(GD-3) connector cable) Connector 2 or 4 can be used to connect the optional lighting arrester using the optional adapter (to convert
M25 × 1.5 screw thread to 1/2 NPT screw thread).
 Connector 5 is used for HART communication with an optional HART modem connector. Do not insert
external cables or connect a lightning arrester. Blank off with a blanking plug if you do not use HART
communication.
 Blank off unused connectors with blanking plugs.
 For more information on using the individual connectors, refer to ‘4-7 Cable connection’.
24 / 1752. Important Safety Information

2-4 Safety information<Components that can be connected (SD-3/SD-3SC)>
The following components can be connected to the main unit (SD-3/SD-3SC):
Connector Connector Connector Connector Connector Connector
1
2
3
4
5
6
Sensor assembly

×

×

×

×

×

〇

EC barrier

×

×

×

×

×

〇

Approved cable gland

〇

〇

×

〇

×

〇

M25 plug

〇

〇

×

〇

〇

×

Adapter(M25 ⇔ 1/2NPT)

〇

〇

×

〇

×

〇

Adapter(M25 ⇔ 3/4NPT)

〇

〇

×

〇

×

〇

Adapter(M25 ⇔ M20)

〇

〇

×

〇

×

〇

Lightning arrester

×

〇

×

〇

×

×

〇: Can be connected
×: Cannot be connected

NOTE
 Connect only components that are compatible with the individual connectors on the main unit (SD-3/SD3SC).
 Tighten M25 plugs and adapters to a torque of at least 30 Nm.
 Secure a minimum thread engagement of five threads.

<Lightning arrester details>
Manufacturer
Name/No.
Part
Explosion-proof
performance
No. and issue
Certification
Nos.

Rating
Installation

Applicable standards
Voltage/current
Temperature*
Attachment screw

Eaton Electric Limited
TP48 or TP32 series surge protector
II 2G Ex db IIC T6 Gb
IECEx BAS 15.0056X Issue 1, Baseefa 04 ATEX 0053X
EN 60079-0:2012+A11:2013
EN 60079-1:2014
IEC 60079-0:2011 Edition 6.0
IEC 60079-1:2014 Edition 7.0
48 V DC-40 - +70 °C
1/2NPT*The minimum ambient temperature for the SD-3/GD-3 when using a surge protector is -40 °C.

25 / 1752. Important Safety Information

2-4 Safety information

The “X” at the end of the certificate number indicates the following special operating conditions:Certificate numbers

IECEx BAS 15.0056X
Baseefa 04 ATEX 0053X“X” specific operating conditions

Judgment

Use terminals suitable for the operating conditions or use
appropriate termination within the bonds to protect against
mechanical damage—for example, when pulling
connector cables.

Conforms asassembly.

These devices are not equipped with grounding or
external connectors to junction conductors. The user is
responsible for attaching and ensuring adequate
grounding.

Conforms asassembly.

This device is also provided as an “Ex i” version andfeatures markings for both. The user is responsible fordetermining explosion-proof performance.

Not applicable

When attaching to a flame-proof housing, apply highstrength thread-locking compound to the mounting screw
on the surge protector.

“X” marking

26 / 1752. Important Safety Information

2-4 Safety information<Components that can be connected (GD-3)>

Connector 1

Connector 2Connector 3

The following components can be connected to the remote sensor head (GD-3):
Connector
1

Connector
2

Connector
3

Sensor assembly

×

×

〇

EC barrier

×

×

〇

Approved cable gland

〇

〇

×

M25 plug〇〇〇

Adapter(M25 ⇔ 1/2NPT)

〇

〇

〇

Adapter(M25 ⇔ 3/4NPT)

〇

〇

〇

Adapter(M25 ⇔ M20)

〇

〇

〇

〇: Can be connected
×: Cannot be connected

NOTE
 Connect only components that are compatible with the individual connectors on the remote sensor head
(GD-3).
 Tighten M25 plugs and adapters to a torque of at least 30 Nm.
 Secure a minimum thread engagement of five threads.

27 / 1752. Important Safety Information

2-4 Safety information<Connection examples>
SD-3SCGD-3RI

SD-3SCGD-3ECB

28 / 1752. Important Safety Information

2-4 Safety information<Exploded view><SD-3>

Container

Cover
Blanking plug

Blanking plug

Gas sensor
Sensor guard<GD-3>

Container

Cover
Blanking plug

Gas sensor

Sensor guard

29 / 1752. Important Safety Information

2-4 Safety information<Screw holes on rear of container (SD-3)>
Four screw holes are located on the rear of the main unit container.
• Screw size: M5• Pitch: 0.8• Screw depth: 5• Maximum allowable length of male screw:
Lmax = 4.2 mm + x(“x” is the intermediate part thickness.)

Screw holes on rear ofcontainer (four locations)<Screw holes on rear and underside of container (GD-3)>
There are four screw holes on the rear of the container and four screw holes on the underside.
• Screw size: M5• Pitch: 0.8• Screw depth: 5• Maximum allowable length of male screw:
Lmax = 4.2 mm + x(“x” is the intermediate part thickness.)<Container rear>
Screw holes on rear of container(four locations)<Container underside>

Screw holes on underside ofcontainer (four locations)

30 / 175

3. Product Configuration

3-1 Main unit and accessories

3

Product Configuration
3-1 Main unit and accessories
Open the box and packaging and inspect the main unit and accessories.
If anything is missing, contact RIKEN KEIKI.

3-1-1 Main unit (SD-3)<Diffusion type><Model without EC barrier><Model with EC barrier>

74
74<Suction type><Model without EC barrier><Model with EC barrier>

74

74

31 / 175

3. Product Configuration

3-1 Main unit and accessories

3-1-2 Main unit (SD-3SC)
74

3-1-3 Remote sensor head (GD-3)<Diffusion type><Model without EC barrier><Model with EC barrier>

32 / 175

3. Product Configuration

3-1 Main unit and accessories

3-1-4 Standard accessories
Standard accessory

Quantity

Part No.

Variesdependingon quantity
ordered.

4286 9200 80

Key used to control the
product

Operating lever

×1

2594 0481 90

Tool used when connecting
cable to terminal plateHex key wrench(2 across flats)

Variesdependingon quantity
ordered.

1510 5020 40

Tool used for tightening M4
hex socket set screws

Control key

OperatingmanualDescription

×1

NOTE
 The quantity of control keys and hex key wrenches included will vary depending on the quantity of
product units ordered.
1 - 10 units:
×1
11 - 20 units:×2
21 - 50 units:
×3
51 or more units: ×4

CAUTION Use the control key provided to operate the product. The product may not respond properly to commands
if an object other than the supplied control key is used.
 The control key provided incorporates an extremely strong magnet. Holding the control key close to credit
cards, ID cards, or other magnetized products may corrupt data recorded on these objects.

33 / 175

3. Product Configuration

3-1 Main unit and accessories

3-1-5 Optional accessories
Optional accessory

Calibration adapter(for IRF sensor)

Calibration adapter(for combustible gas
sensor)Calibration adapter(for ESF sensor)

Part No.

Description

4283 9011 00

SD-3RI calibration adapter<Material>
Body: PP
Nipple: Stainless steel/Teflon

4283 9012 70

SD-3NC/GH/GHS/SP
calibration adapter<Material>
Body: PP
Nipple: Stainless steel/Teflon

4283 9013 40

SD-3EC/ECS/ECB calibration
adapter<Material>
Body: PP
Nipple: Stainless steel/Teflon

Wall mounting
4283 9019 80
Protective coverPole mounting
4283 9045 60

Sunshade coverSplash guard(for IRF sensor)

34 / 175

Cover to protect the SD-3
main unit<Material>
SUS3164283 9015 90

Cover to suppress
temperature rises due to
direct sunlight or radiant heat
<Material>
SUS3164283 9076 60

SD-3RI cover to protect
sensor from water and dust
The identification number “1”is engraved on the underside.
<Material>Resin3. Product Configuration

3-1 Main unit and accessories

Optional accessory

Part No.

Description

4283 9077 80

SD-3NC/GH/GHS/SP cover toprotect sensor from water anddust
The identification number “2”is engraved on the underside.
<Material>
Resin

Splash guard(for ESF sensor)

4283 9078 50

SD-3EC/ECS/ECB cover toprotect sensor from water anddust
The identification number “3”is engraved on the underside.
<Material>
Resin

Blanking plug

4283 9018 10

M25 × 1.5 blanking plug
<Material>
Equivalent to SUS316

4283 4081 70

Adapter to convert M25 × 1.5
screw thread to 1/2NPT screw
thread<Material>
Equivalent to SUS316

4283 4082 40

Adapter to convert M25 × 1.5
screw thread to 3/4NPT screw
thread<Material>
Equivalent to SUS316

4283 4132 20

Adapter to convert M25 × 1.5
screw thread to M20 × 1.5
screw thread<Material>
Equivalent to SUS316

4283 0030 20

Filter for removing trace
amounts of silicone from theair. This can extend sensor
life.*2

Splash guard(for combustible gas
sensor)

Adapter

Adapter

Adapter

Silicone removal filter(SI-8)*1(for NCF/SGF/SHF
sensor)35 / 175

3. Product Configuration

3-1 Main unit and accessories

Optional accessory

Part No.

Description

Activated carbon filter(CF-8304) *1(for NCF/SGF/SHF
sensor)4283 0040 10

Filter for removing trace
amounts of silicone from theair. This can extend sensor
life.
The silicone removal
capability of this filter exceedsthat of the silicone removal
filter.*3
It can also be used to remove
interference gases. This canminimize interference effects
from gases other than thedetection target gas.

Duct mounting kit(for GD-3RI)(for GD-3NC/GH/SP)(for GD-3EC)

4262 9674 104262 9675 90
4262 9676 60

Kit for installing a remotesensor head (GD-3) to a duct
<Material>
SUS316

Mounting angle for
GD-3

4283 4319 20

This angle is used to mountthe GD-3 with splash guard
on the wall.
<Material>
SUS316

Tag plate with wire
chain

0717 0319 40

Tag plate made of SUS316.
It can be attached to theenclosure of this unit.

HART modem
connector

2905 2439 10

Connector used whenconnecting a HART modem

Lightning arrester (3wire connection)(TP48-3-N-NDI)

4283 9055 50

Device to limit momentary
surge voltages caused bylightning strikes

Lightning arrester (4wire connection)(TP48-4-N-NDI)

4283 9056 20

Device to limit momentary
surge voltages caused bylightning strikes

36 / 175

3. Product Configuration

3-1 Main unit and accessories

Optional accessory

Part No.

Fuse

U boltDescription

2564 0125 10

Littelfuse’s fuse
(1.25 A, 100 V DC)

4283 9046 30

Bolt used for mounting themain unit to a pole (size: 50A(2B))<Material>
SUS316*1: If you use a filter, we recommend fitting a splash guard.
*2: Installing the silicone removal filter will limit the target gases that can be detected.
*3: The range of target gases that can be detected will be more limited than when the silicone removal filter is fitted.

37 / 175

3. Product Configuration

3-2 Part names and functions

3-2 Part names and functions＜SD-3＞<Display (same for both SD-3 and SD-3SC)>⑥ ⑦ ⑧ ⑨ ⑩

①

④

②

⑭
⑤

③

＜SD-3SC＞

⑪ ⑫ ⑬

No.
①

②
③

④
⑤
⑥
⑦
⑧
⑨
⑩
⑪

Name
MENU/ESC key

Function
Hold down this key in detection mode to switch to user mode.
In user mode and maintenance mode, this key is used to cancel a settingor return to the previous screen.
Hold down this key in user mode or maintenance mode to return todetection mode.
7-segment LED display Displays the gas concentration and other information.
Press in detection mode to display the ALM1 (first alarm) and ALM2
SET key(second alarm) alarm setpoints.
In user mode and maintenance mode, this key is used to confirm a value
or select a setting.
In user mode and maintenance mode, this key is used to select a setting▲ key
item and adjust (increase) a value.
In user mode, this key is used to switch menus or adjust (lower) a value.
▼ key
Press in detection mode to display the external output.
Powerlamp. Lights up in green when the power is on.
Power lamp
The lamp flashes in green in user mode and maintenance mode.
(POWER)
ALM1 (first alarm) alarm lamp. Lights up in red when the ALM1 (first alarm)
Alarm lamp (ALM1)
alarm setpoint is reached.
IrDA communication port
Infrared port
ALM2 (second alarm) alarm lamp. Lights up in red when the ALM2
Alarm lamp (ALM2)(second alarm) alarm setpoint is reached.
Fault lamp. Lights up in yellow when an abnormality is detected in the product.
Fault lamp (FAULT)PPM lamp⑫%LEL lamp⑬% lamp⑭

SensorLights up in green when a ppm concentration range gas concentration isdisplayed.
Lights up (green) when a gas concentration within the %LEL concentration
range is displayed.
Lights up in green when a vol% concentration range gas concentration isdisplayed.
Incorporates a gas-detecting sensor.

38 / 175

3. Product Configuration

3-3 Block diagrams

3-3 Block diagrams
The block diagrams (electrical circuit diagrams) for the product are given below.

<SD-3>
Power supply unit
24 V DC

Display (LED)・ POWER・ ALM1
・ ALM2
・ FAULT・ PPM
・ %LEL
・ %Power supply voltage converter

External output
4 - 20 mA + HART

HART modem

Alarm contact output (option)
1. Gas alarm output (ALARM1)
2. Gas alarm output (ALARM2)
3. Fault output (FAULT)

Control
unit
CPU

Display
7-segment LED

Magnetic operation part・ MENU/ESC
・ SET
・ ▲
・ ▼

Contact operation
Normal measurement:
De-energized
Alarm state: EnergizedSensor39 / 175

3. Product Configuration

3-3 Block diagrams<SD-3SC>Power supply unit
24 V DC

Display (LED)・ POWER・ ALM1
・ ALM2
・ FAULT・ PPM
・ %LEL
・ %Power supply voltage converter

External output
4 - 20 mA + HART

HART modem

Alarm contact output (option)
1. Gas alarm output (ALARM1)
2. Gas alarm output (ALARM2)
3. Fault output (FAULT)

Control
unit
CPU

Display
7-segment LED

Magnetic operation part・ MENU/ESC
・ SET
・ ▲
・ ▼

Contact operation
Normal measurement:
De-energized
Alarm state: Energized

GD-3<GD-3>

SD-3SC
Controlunit
CPUPower supply voltage converter

40 / 175

Sensor4. Installation

4-1 Installation precautions

4

Installation
4-1 Installation precautions
Selecting an appropriate installation location is vital for system performance.
Be sure to observe the following precautions before installing.
Failure to comply with these precautions may result in failure of the product or improper function.

CAUTION The product is a precision device. Certain conditions at the location (environment) where the product isinstalled may prevent optimum performance. Check the environment at the installation location and takeall required precautionary measures depending on circumstances.
 Install the number of units needed at the appropriate locations to ensure that the product plays animportant role in safety and disaster prevention.
 Areas where gas is likely to leak or accumulate will differ depending on the gas type and individual work
areas. Thoroughly consider the installation locations and number of units to be installed before
installation.
 Dirt, snow, mud, or external devices must not prevent gas or vapor from contacting the sensor. The
protection class does not guarantee that the instrument will successfully detect gases during and after
exposure to these conditions. Check the operation and calibrate the instrument if it has been exposed todust deposits, submersion, or high pressure water.
 The recommended installation orientation of the detector is with the sensor facing downward. Other
orientations are acceptable if the sensor is protected from mechanical damage, dirt, and water intrusion.
 Use genuine special accessories.

4-1-1 General installation information
Observe the following precautions when installing the product: If the product is installed in a location where the ambient temperature exceeds 65 °C, use cables designed foruse at temperatures at least 5 °C above the maximum anticipated ambient temperature.
 The SD-3 and SD-3SC main units each have two M25 × 1.5 connectors for use when wiring in the field.
Connectors must always be blanked off with blanking plugs when not in use.
 The GD-3 has two M25 × 1.5 connectors for connecting the SD-3SC. The connector not in use must be
blanked off with a blanking plug at all times.
 Do not mount a sensor that uses a different detection principle from the model type.
 Use ferrules on the ends of stranded cables.
 Secondary circuits should be supplied from an insulated source. (Not suited to alarm relay contacts) If installing without using conduits, use cable glands that comply with the explosion-proof certification. In
addition, connect cable shielding to the main unit, cable glands, and indicators to increase immunity toelectromagnetic noise and other external factors.
 Select the cable, terminal plate, and other parts for wiring to alarm relays (optional) to suit the rated voltage,current, and environmental conditions.
In addition, carefully consider the following points when installing:
41 / 1754. Installation

4-1 Installation precautions

 All possible effects on the installation of the gas detector system
 Restrictions and regulations concerning the installation of the gas detector system
 Regulations concerning the operation, power supply, and signal cable connections for the gas detector
system Ambient environmental effects to which the gas detector system may be subject
 Specifics of the physical characteristics, environmental air movement and flows, and latent leaks of thedetection gas
 Accessibility for required maintenance and the shape of the accessories used

4-1-2 Restrictions regarding installation<Do not install in locations subject to vibration or impact.>
The product contains precision electronic components. Install the product in a stable location not exposed tovibration, impact, or risk of falling.

<Do not install in locations exposed to water, oil, or chemicals.>
Avoid installing in locations that pose the risk of splashing liquids such as water, oil, and chemicals. Deploy the
optional protective cover (main unit protection) and splash guard (sensor protection) if the product must be
installed in a location where it may be exposed to these factors.

<Do not install in locations where temperatures exceed the operating temperature
range.>For information on the product operating temperature range, refer to ‘10-3. Detection target gases for individual
detection principles’.
Install in a stable location where temperatures do not exceed the operating temperature range during use.

<Do not install in locations subject to direct sunlight or sudden temperature changes.>
Install away from locations subject to direct sunlight or radiant heat (infrared radiation from high temperature
bodies) and locations subject to sudden temperature changes. Failure to do so may expose the product totemperatures that exceed specified thresholds, internal condensation, or rapid temperature fluctuations the
product cannot handle.
Use of the optional sunshade cover is recommended when using the product in locations subject to direct
sunlight.

<Do not install in locations where maintenance is dangerous or not possible.>
The product requires periodic maintenance.
Do not install in the following or similar locations where maintenance is dangerous or not possible: Locations where systems must be stopped to allow maintenance Locations where part of the system must be detached to allow maintenance Locations where the product cannot be removed due to the presence of pipes or racks
 Locations where maintenance work is hazardous—for example, close to high-voltage cables<Do not install in improperly grounded system housings.>
When installing in a system housing, be sure to implement a Class D-equivalent ground connection.

<Do not install in the presence of miscellaneous gases.>
Do not install in locations where the following gases are present:
Sensor type

Gases affecting sensor sensitivity

SGF・ Organic silicone gas (e.g., D4 siloxane, D5 siloxane)
・ Sulfur gases (e.g., SOX, H2S)
・ Polymerization substances (ethylene oxide,
acrylonitrile, butadiene, styrene, etc.)
・ Catalyst poison (phosphorus compounds,
halogenated hydrocarbons, metal vapor, etc.)
・ The degree of influence depends on the sensor
model.

SHF

NCF

IRF

None

ESF

None
42 / 175

Sensor-corroding gases

・ Corrosive gases (e.g., SOX,
NOX)・ Acid gases (e.g., HF, HCl)None

4. Installation

4-1 Installation precautions<Precautions when installing in the presence of interference gases>
Take care when installing in locations where the following interference gases are present:
Sensor typeInterference gas
SGF
SHF

Hydrocarbons, alcohols, organic solvents, etc. other than the target gas

NCF

Hydrocarbons, alcohols, organic solvents, etc. other than the target gas

IRF

Combustible gas sensor: Hydrocarbons, alcohols, organic solvents, etc. other than thetarget gas
CO2 sensor: CO, N2O, NO, etc.

ESF

Differs depending on sensor. (e.g., H2 with CO sensor)<Use the appropriate power supply and power cable.>
The product requires a 24 V DC (18 V - 30 V DC) power supply to operate. The power cable used should havea cross section of 1.308 mm2 (AWG16) or 2.082 mm2 (AWG14). Use shielded 3-core or 4-core cable.
For the installation of cables and power supply
Due to the resistor value of the cable, a voltage drop occurs, causing the actual voltage supply to SD-3 (at theSD-3 terminal) to be lower than the voltage supply at the power source. Because of this, when the voltage
drop by the cable causes the actual voltage supply to become below 18VDC, the voltage supply at the powersource needs to be increased.
This voltage drop is determined by the type and length of the cable, ambient temperature, as well as the current
consumption value of SD-3.
The current consumption value of SD-3 varies depending on the sensor type and the alarm relay state in the
SD-3.
<How to obtain the voltage supply at the power source -1>
Use the equation below to obtain the voltage supply value at the power source.
Voltage supply at the power source= A (Current consumption of SD-3) x B (Resistor value of the cable to be installed) + 18V
A: Current consumption of SD-3
Choose from the list below.（＠18V）
Type
Current consumption(max.)
SD-3RI
170mA
SD-3NC
200mA
SD-3EC
140mA
SD-3ECS
140mA
SD-3ECB
150mA
SD-3GH
200mA
SD-3SP
160mA
SD-3SC＋GD-3RI
180mA
SD-3 SC＋GD-3NC
220mA
SD-3 SC＋GD-3EC
150mA
SD-3 SC＋GD-3ECS
150mA
SD-3 SC＋GD-3ECB
160mA
SD-3 SC＋GD-3GH
220mA
SD-3 SC＋GD-3SP
180mA

Remarks

B: Resistor value of the cable to be installed
The maximum resistor value can be determined by the type and length of the cable to be installed,
43 / 1754. Installation

4-1 Installation precautions

and the upper limit of the operating temperature.
e.g.)
A: The maximum current consumption value = 170 mA (SD-3RI)
B: The maximum resister value of the cable to be installed = 24Ω (CVV-S, 1.308 mm2, 1250m, ＠70℃)
Voltage supply at the power source = 170mA x （24Ω x2）＋18V= 8.16V＋18V= 26.16V (or higher)<How to obtain the voltage supply at the power source -2>
When the method in 1 cannot be applied because the type and length of the cable to be installed is unknown, or
to make sure if the voltage calculated in 1 poses no problem for the actual voltage to supply, use this method
described here.
Alarm test is performed under the following conditions (refer to 7-3-2 Performing alarm test).
Set the contact action ON.
Press ▲ key to increase the indicator until it reaches full scale over (nnnn), and when that happens, make surethat the voltage of the SD-3 terminal block is over 18VDC.
Fault test is performed under the following conditions (refer to 7-3-3 Performing fault test).
Set the Fault test ON.
When that happens, make sure that the voltage of the SD-3 terminal block is over 18VDC.
If it’s below 18VDC, then increase the voltage supply at the power source. If the temperature at this point
increases during the operation, give enough margin to the voltage supply by compensating the voltage drop
caused by the increase of the cable resistor value.

<Install away from noise-emitting devices (main unit and cables).>
Install away from locations where high-frequency or high-voltage devices are present. Failure to do so may
result in electromagnetic interference.

<Use the appropriate impedance for the 4 - 20 mA signal output.>
The impedance for the 4 - 20 mA signal output must not exceed 600 Ω to ensure correct operation. This willvary depending on the voltage supplied to the product. The maximum and minimum impedance specified mustbe satisfied, based on factors such as product operating voltage and interface (HART).
<4 - 20 mA signal output impedance derating depending on supply voltage differences>

4 - 20 mA output load derating
700 Ω
600 Ω
500 Ω
400 Ω
300 Ω
200 Ω
100 Ω
0Ω
30 V 29 V 28 V 27 V 26 V 25 V 24 V 23 V 22 V 21 V 20 V 19 V 18 V 17 V 16 V 15 V

<4 - 20 mA signal output impedance range when using HART communication>
44 / 1754. Installation

4-1 Installation precautions

Devices equipped with a HART interface can be operated via HART communication or HART multidrop mode.
Operating mode

Signal impedance range for power supply voltage

Operation without HART communication

Max. 300 Ω at 18 V DC
Linear increase to max. 600 Ω at 23 V DC

Operation with HART communication(HART mode)

Min. 250 Ω in range 18 V - 30 V DC

HART multidrop operation

250 Ω to 600 Ω in range 18 V - 30 V DC

Max. 300 Ω at 18 V DC
Linear increase to max. 600 Ω at 23 V DC

<Use alarm contacts correctly.>
The alarm contacts on the product are used to transmit signals for operating external buzzers, alarm indicator
lamps, or revolving lights. Never use for controls on which human life depends or other mission critical controls(e.g., shutoff valve controls).
Check contact opening and closing periodically, including during regular maintenance. Contacts may not
function correctly under certain operating conditions if left inactive for extended periods.
The alarm contact specifications for the product apply under resistance load conditions. If inductive loads occur
at the alarm contacts, a counter-electromotive force will be generated at the contacts, leading to the following
potential problems:• Alarm relay contact welding, insulation failure, contact failure• Damage to electrical components due to high voltage inside the product• Malfunctions due to CPU runaway
If the product is used to operate loads, take the following measures to stabilize product operations and protect thealarm contacts:• Use an external relay (low voltage, not exceeding 100 V AC) to link the circuits (contact amplification). Add asurge absorber (SK1) appropriate for the rating to the external relay.
• Where necessary, add a surge absorber (SK2) on the load side of the external relay.
• Depending on the load conditions, it may be better to add the surge absorber to the contact side. Check load
behavior to determine the optimal location.
<SD-3>

Load

Coil

Alarm
contactPowersupplyPowersupplyExternal relay(low voltage relay)* SK1, SK2: Surge absorbers

45 / 1754. Installation

4-1 Installation precautions

DANGER Never use for controls on which human life depends or other mission critical controls (e.g., shutoff valve
controls).

WARNING Contacts may not function correctly if left inactive for extended periods. Check contact opening andclosing periodically.
 Contact faults may occur if exposed to organic gases or sulfidizing gases for extended periods.
 In principle, do not use the alarm contacts of the product to operate inductive loads. In particular, never
use to operate devices like fluorescent lamps and motors.
 If operating inductive loads is absolutely unavoidable, link the circuits using an external relay (contact
amplification). Since the external relay coil constitutes another inductive load, use a relay operating at low
voltage (under 100 V AC), and protect the product contacts with a suitable surge absorber (e.g., CR
circuit).
 Do not use in atmospheres where silicone is present.

CAUTION A de-energized b contact (break contact) may result in momentary opening in the event of an external
force or other physical impact. If a b contact is used as an alarm contact, implement measures to accountfor such momentary operations—for example, by adding a delay operation (of approximately one
second) to the signal on the b contact receiving side.

46 / 1754. Installation

4-2 System design precautions

4-2 System design precautions
Consider the following precautions when designing a system in which the product is used:

CAUTION An unstable power supply or noise may result in malfunctions or false alarms.
 Consider the details described in this section before designing a system that uses the product.

4-2-1 Using a stable power supply
The product’s external output and alarm contacts may activate as the system stabilizes when the power isturned on or right after an instantaneous power failure. If external output and alarm contacts activate due topower failures or other reason, use a UPS (uninterruptible power system) or take other appropriate measures.
The product should be powered using a power supply specified below.
Power supply voltage 24 V DC (18 V - 30 V DC): Main unit terminal voltage
Typical action:
Up to approx. 20 ms*1
Time allowed for
Use an external uninterruptible power
instantaneous
supply or similar system to guarantee
power failurescontinuous operation and functionality.
Do not use with power supplies
Typical action:
Miscellaneous
subject to very high power loads orWhere necessary, use a line filter or otherhigh frequency noise.
device. Keep the product away fromsources of noise.
*1: Restart the product when recovering after instantaneous power failures of 20 ms or more.

4-2-2 Lightning strike protective measures
In factories or plants where cabling is configured as follows, damage may result in the event of lightning strikes
due to the cables connected to the devices acting as a receiving antenna for the lightning: When cables are installed outdoors
 When cables are installed in the same duct as cables supplied from outside
In the event of lightning strikes, devices connected to the cables may be damaged by lightning energy.
Additionally, note that inductive lightning surges due to lightning strikes cannot be entirely prevented, even if
cables are installed in metal ducts or buried underground. While it is not possible to completely protect against
lightning disasters, the following protective measures are useful:<Lightning strike protective measures>
Implement appropriate measures based on environmental conditions and the importance of the facility.
A lightning arrester (cable protector) can be installed before the field devices and central processing equipment
as a safeguard against inductive lightning surges transmitted through the cables.
For information on how to use lightning arresters, please contact the manufacturer.

<Grounding>
Surge noise is caused by lightning strikes and other factors. Devices must be grounded to protect against thesenoise sources.

NOTE Lightning arresters contain circuitry to remove voltage surges that could damage field devices. Installing
lightning arresters may therefore cause signal attenuation.
Perform an operation check before installing a lightning arrester. Also note that lightning arresters cannot
remove all voltage surges.

47 / 1754. Installation

4-3 Providing maintenance space

4-3 Providing maintenance space
When mounting the product, allow space to open and close the covers during maintenance.

<Main unit (SD-3/SD-3SC)>
1200

300

*The diagram illustrates the SD-3. The maintenance space for the SD-3SC is identical.

<Remote sensor head (GD-3)>
1100

300

48 / 1754. Installation

4-3 Providing maintenance space

CAUTION
The product requires periodic maintenance.
Do not install in the following or similar locations where maintenance is dangerous or not possible: Locations such as within systems that must be stopped for maintenance Locations where part of the system must be detached to allow maintenance Locations where the product cannot be removed due to the presence of pipes or racks
 Locations where maintenance work is hazardous—for example, close to high-voltage cables

49 / 1754. Installation

4-4 Main unit installation

4-4 Main unit installation
4-4-1 Vertical pole mounting
Mount the main unit (SD-3/SD-3SC) to a vertical pole (size: 50A (2B)) using two U bolts.
1

Fit one U bolt around the vertical pole and through the upper slots on the main unit.

2

Secure the U bolt to the main unit with two washers, two spring washers, and two M10 nuts.

3

Fit the second U bolt around the vertical pole and through the lower slots on the main unit.

4

Secure the U bolt to the main unit with two washers, two spring washers, and two M10 nuts.
Vertical pole

U bolts

Upper slots

Lower slots*The diagram illustrates the SD-3. The mounting method for the SD-3SC is identical.

50 / 1754. Installation

4-4 Main unit installation

4-4-2 Wall mounting
Mount the main unit (SD-3/SD-3SC) to a wall.
1

Place the main unit against the wall surface and secure with four M10 double SEMS bolts.
Bolt positions

Bolt positions*The diagram illustrates the SD-3. The mounting method for the SD-3SC is identical.

CAUTION
The product requires periodic maintenance.
Do not install in the following or similar locations where maintenance is dangerous or not possible: Locations such as within systems that must be stopped for maintenance Locations where part of the system must be detached to allow maintenance Locations where the product cannot be removed due to the presence of pipes or racks
 Locations where maintenance work is hazardous—for example, close to high-voltage cables

51 / 1754. Installation

4-4 Main unit installation

4-4-3 Attaching protective coverAttach the protective cover to the main unit (SD-3/SD-3SC).

<Pole mounting (pole size: 50A (2B))>
1

Attach the chassis and mounting bracket to the main unit.
Secure with four M5  6 double SEMS bolts from behind,as shown in the diagram to the right.

ChassisMounting
bracket2

Fit one U bolt around the vertical pole and through theupper slots on the main unit. Secure with two washers, two
spring washers, and two M10 nuts.

3

Fit the second U bolt around the vertical pole and throughthe lower slots on the main unit. Secure with two washers,
two spring washers, and two M10 nuts.
U bolts

4
5

Attach the protective cover, aligning it with the two lugs at
the top of the chassis.

Lugs

Secure the protective cover in place by tightening theknurled screws on either side of the cover.

Protective cover

Knurled screw*The diagram illustrates the SD-3. The mounting method for the SD-3SC is identical.

52 / 1754. Installation

4-4 Main unit installation<Wall mounting>1

Secure the main unit and chassis with four M10 double
SEMS bolts.

ChassisLugs

2

Attach the protective cover, aligning it with the two lugs at
the top of the chassis.

3

Secure the protective cover in place by tightening theknurled screws on either side of the cover.

Protective cover

Knurled screw*The diagram illustrates the SD-3. The mounting method for the SD-3SC is identical.

53 / 1754. Installation

4-4 Main unit installation

4-4-4 Attaching sunshade coverAttach the sunshade cover to the main unit (SD-3/SD-3SC).

<Pole mounting (pole size: 50A (2B))>
1

2

Fit one U bolt around the vertical pole and through theupper slots on the main unit. Secure with the chassis, twowashers, two spring washers, and two M10 nuts.

ChassisU bolts

Fit the second U bolt around the vertical pole and throughthe lower slots on the main unit. Secure with two washers,
two spring washers, and two M10 nuts.

Vertical pole

3
4

Attach the sunshade cover, aligning it with the two lugs at
the top of the chassis.

Lugs

Secure the sunshade cover in place by tightening theknurled screws on either side of the cover.

Sunshade cover

Knurled screw*The diagram illustrates the SD-3. The mounting method for the SD-3SC is identical.

54 / 1754. Installation

4-4 Main unit installation<Wall mounting>1

Secure the main unit and chassis with four M10 double
SEMS bolts.

2

Attach the sunshade cover, aligning it with the two lugs at
the top of the chassis.

3

Secure the sunshade cover in place by tightening theknurled screws on either side of the cover.

Chassis

Lugs
Sunshade cover

Knurled screw*The diagram illustrates the SD-3. The mounting method for the SD-3SC is identical.

55 / 1754. Installation

4-5 Remote sensor head (GD-3) installation

4-5 Remote sensor head (GD-3) installation
4-5-1 Wall mounting
1

Place the remote sensor head (GD-3) against the wall surface and secure with two M6 double SEMS
bolts.

Bolt positions

4-5-2 Duct mounting
Attach the remote sensor head (GD-3) to a duct.
Attach to a duct using the duct mounting kit.
The duct mounting kit has the following dimensions:Remote sensor head (GD-3)

1

Cut out an opening in the top of the duct.
Refer to the diagram to the right for thedimensions of the opening.

Top of duct

100

180

56 / 1754. Installation

4-5 Remote sensor head (GD-3) installation2

Insert the remote sensor head (GD-3) into the duct
mounting kit and secure with four M5 bolts.
Connect a tube to the sensor on the remote sensor head
(GD-3) to enable calibration. The tube should protrude fromthe top of the duct mounting kit.

3

Insert the duct mounting kit into the opening in the duct.
Secure in place with six M6 bolts.

Duct mounting kit

NOTE

300 or more

 When mounting the remote sensor head (GD-3) inside a duct,
make sure the sensor is not in contact with the duct inner wall.
 In the duct-mounted version, for external gas calibration,
make a piping connection between the guard attached to thesensor section and the duct-mounted gas IN.

Duct

57 / 1754. Installation

4-6 Connecting the grounding terminal

4-6 Connecting the grounding terminal
WARNING Be sure to ground the product before turning on the power.
 To ensure stable operation and safety, be sure to ground the product. Never connect grounding wires togas pipes.
 Make sure the grounding is Class D equivalent (grounding resistance not exceeding 100 Ω).
 Use cable lugs on the grounding wire to ensure safe grounding with the cable free of slack and twisting.
 Do not ground to the same locations as high frequency or high voltage devices or nearby.
Connect the grounding bolt to the local grounding terminal.
<Main unit (SD-3)>

Grounding bolt (M4)<Main unit (SD-3SC)>

Grounding bolt (M4)NOTE
 The grounding bolt is marked with thesymbol.

58 / 175<Remote sensor head (GD-3)>

Grounding bolt (M4)

4. Installation

4-7 Connecting the power and signal cables

4-7 Connecting the power and signal cables
4-7-1 Main unit cable and device connectors
The cable and device connectors on the main unit are as follows:<SD-3>・Power supply and signal
cables, max 2.0 mm2(shielded)
・Lightning arrester (TP-48)<Optional>
・Power supply and signal
cables, max 2.0 mm2(shielded)
・Lightning arrester(TP-48)<Optional>
・HART modem connector(Cannot be used in
explosion-proof areas)

Contact output
max 2.0 mm2 (shielded)<SD-3SC>・Power supply and signal
cables, max 2.0 mm2(shielded)
・Lightning arrester (TP-48)<Optional>
・Power supply and signal
cables, max 2.0 mm2(shielded)
・Lightning arrester(TP-48)<Optional>
・HART modem connector(Cannot be used in
explosion-proof areas)

Contact output
max 2.0 mm2 (shielded)

Remote sensor head (GD-3) connector cable,
max 2.0 mm2 (shielded twisted pair)

59 / 1754. Installation

4-7 Connecting the power and signal cables

NOTE
 Use the approved cable glands when connecting the remote sensor head (GD-3).
 Up to two external cable connectors can be used at the same time (excluding the remote sensor head
(GD-3) connector cable). Use the approved cable glands for the connection.
 Blank off unused connectors with blanking plugs.
 Do not use more than one adapter per connector.
 Do not use an adapter together with a blanking plug.

60 / 1754. Installation

4-7 Connecting the power and signal cables

4-7-2 Connecting the power and signal cables to the main unit
Connect the power cable, signal cable, and contact cables to the main unit (SD-3/SD-3SC).
1

Unscrew the M4 hex socket set screw on the main unit
cover, then rotate the cover counterclockwise toremove.
Use a hex key wrench (2 across flats) to unscrew the M4
hex socket set screw.
Be careful to avoid dropping the cover while unscrewing andremoving it.

2

Unscrew the two M3 screws securing the display unit.

3

Pull out the display unit and hang on the lug on the
housing.
The display unit is connected to the terminal plate unit by aflat cable. Pulling with excessive force may disconnect thecable.
During the removal process, avoid pulling on the display unit
with excessive force.

4

Lug on housing

Lug on housing

Ground the main unit.
Make sure the grounding is Class D equivalent (grounding
resistance not exceeding 100 Ω). For information on
grounding, refer to ‘4-6 Connecting the grounding terminal’.
Display unit
Grounding bolt

61 / 1754. Installation

4-7 Connecting the power and signal cables

5

Attach cable glands or conduits to the connectors on themain unit.
Use appropriate cable glands or conduits to suit the purpose
and type of the cable.

6

Pull out the terminal plates from the terminal plate board.

7

Connect the power and signal cables to the power andsignal terminal plate.
Connect the cables to the following terminals on the powerand signal terminal plate. For more information on thecontact cable connections, refer to ‘4-9 Alarm relay setting(option)’. For information on connecting cables to theterminal plate, refer to ‘4-7-5 Connecting cables to theterminal plate’.

Cable gland

Cable gland

Power and signal
terminal plate

Contact output terminal plates

Crimping terminal

Sheathing

Insulation

Conductor

Recommended insulation length: 40 - 50 mm

When connecting cables, connect the cable shielding to theterminals at the top left or top right on the inside of the mainunit.
Depending on the installation location, noise interference may
result. If this happens, remove the shielding.
8

Connect the required number of contact cables to thecontact output terminal plates.
For information on connecting cables to the terminal plate, referto ‘4-7-5 Connecting cables to the terminal plate’.

*No contact output terminal plate is present with the no contact output option.

62 / 175

1
2
3
4(The numbers are
terminal numbers.)<Using 3-core cable>
Terminal
Power/signal cable connection
No.
1
Power supply (+)
2
Common (power supply (−), signal (−))
3
Signal (+)<Using 4-core cable>
Terminal
Power/signal cable connection
No.
1
Power supply (+)
2Power supply (−)
3
Signal (+)
4
Signal (−)

1
2
3
4

4. Installation

9

4-7 Connecting the power and signal cables

Mount the terminal plates on the terminal plate board.
Adjust the cable position so that no load is applied to theterminal plates.

Power and signal terminal plate

Contact output terminal plates

10 Return the display unit to its original position andsecure with the two M3 screws.
Take care not to trap the cable here.

11 Rotate the cover clockwise to attach and secure withthe single M4 hex socket set screw.
Use a hex key wrench (2 across flats) to tighten the M4 hex
socket set screw.
Take care not to trap the cable when attaching the cover.
Rotate the cover clockwise until it moves no further tosecurely fasten in place.

*The diagram illustrates the SD-3. The connection method for the SD-3SC is identical.

63 / 1754. Installation

4-7 Connecting the power and signal cables

4-7-3 Connecting the power and signal cables to the remote sensor head (GD-3)
1

Unscrew the single M4 screw on the remote sensor head
(GD-3) cover.
Use a hex key wrench (2 across flats) to unscrew the M4 hex
socket set screw.
Be careful to avoid dropping the cover while unscrewing andremoving it.

2

Rotate the cover counterclockwise and remove.

3

Attach a cable gland or conduit to the connector on
the remote sensor head (GD-3).
Use an appropriate cable gland or conduit to suit the
purpose and type of the cable.
Cable gland4

Hex key wrench

Terminal plate

Pull out the terminal plate (TN1) from the terminal plateboard.

Terminalplate

64 / 1754. Installation

5

4-7 Connecting the power and signal cables

Connect the power and signal cables to the terminal plate.
Connect the cables to the following terminals on theterminal plate. For information on how to connect cables tothe terminal plate, refer to ‘4-7-5 Connecting cables to theterminal plate’.
Terminal
No.
1
2
3
4

Sheathing

4 3 21

Power/signal cable connection
Power supply (+)
Power supply (−)
Signal (+)
Signal (−)

Insulation(The numbers are
terminal numbers.)

Conductor

Recommended insulation length: 40 - 50 mm

When connecting cables, connect the cable shielding to
the terminals at the top left or top right on the inside of themain unit.
Depending on the installation location, noise interference
may result.
In such cases, remove the shielding.
6

Route the cable from inside the main unit to theconnector.
Route to the connector on the side where the cable glandor conduit is attached.
Cable gland

7

Mount the terminal plate on the terminal plate board.
Adjust the cable position so that no load is applied to theterminal plates.
<With cable (external cable) routed to right-hand side><With cable (external cable) routed to left-hand side>

65 / 1754. Installation

8

4-7 Connecting the power and signal cables

Rotate the cover clockwise to attach and secure with thesingle M4 hex socket set screw.
Use a hex key wrench (2 across flats) to tighten the M4 hex
socket set screw.
Take care not to trap the cable when attaching the cover. Rotate
the cover clockwise until it moves no further to securely fasten
in place.

66 / 175

Hex key wrench4. Installation

4-7 Connecting the power and signal cables

4-7-4 Connecting the main unit (SD-3SC) and remote sensor head (GD-3)
1

Unscrew the M4 hex socket set screw on the main unit
(SD-3SC) cover, then rotate the cover counterclockwise
to remove.
Use a hex key wrench (2 across flats) to unscrew the M4
hex socket set screw.
Be careful to avoid dropping the cover while unscrewing andremoving it.

2

Unscrew the two M3 screws securing the display unit.

3

Pull out the display unit and hang on the lug on the
housing.
The display unit is connected to the terminal plate unit by aflat cable. Pulling with excessive force may disconnect thecable.
During the removal process, avoid pulling on the display unit
with excessive force.

Lug on housing

Lug on housing

Display unit

4

Attach a cable gland or conduit to the connector on themain unit.
Use an appropriate cable gland or conduit to suit the
purpose and type of the cable.

Cable gland

67 / 1754. Installation

4-7 Connecting the power and signal cables

5

Pull out the remote connection terminal plate from theterminal plate board.

6

Unscrew the single M3 screw securing the clamp
and remove the clamp.

Screw (M3)

Clamp

7

Connect the power and signal cables extending from theremote sensor head (GD-3) to the remote connection
terminal plate.
Connect the cables to the following terminals on the remoteconnection terminal plate. For information on connecting
cables to the terminal plate, refer to ‘4-7-5 Connecting
cables to the terminal plate’.
Terminal
No.
1
2
3
4

Power/signal cable connection
Power supply (+)
Power supply (−)
Signal (+)
Signal (−)

1

2

3

4

(The numbers are
terminal numbers.)
Sheathing

ShieldingInsulation

Conductor

Recommended shielding length: 30 - 40 mm
Recommended insulation length: 130 - 140 mm

8Mount the terminal plate on the terminal plate board.
Adjust the cable position so that no load is applied to theterminal plates.

68 / 175

Remote connection terminalplate4. Installation

9

4-7 Connecting the power and signal cables

Clamp the shield wire.
Use the single M3 screw to clamp the cableshielding.

ShieldingScrew (M3)Clamp

10 Return the display unit to its original position andsecure with the two M3 screws.
Take care not to trap the cable here.

11 Rotate the cover clockwise to attach and secure with thesingle M4 hex socket set screw.
Use a hex key wrench (2 across flats) to tighten the M4 hex
socket set screw.
Take care not to trap the cable when attaching the cover.
Rotate the cover clockwise until it moves no further tosecurely fasten in place.

69 / 1754. Installation

4-7 Connecting the power and signal cables＜SD-3SC and GD-3 connection example＞
SD-3SC

Cable glands

GD-3

Cable

<SD-3/SD-3SC and RM-5003 terminal plate connection example>

Shielded cable

70 / 1754. Installation

4-7 Connecting the power and signal cables<Indicator connection example>
SD-3
Connect the shield to the grounding
bolt on the chassis<SD-3>
Indicator (e.g., RM-5003)

Power supply(+)
CommonSignal (+)

SD-3SC
Connect the shield to the grounding bolton the chassis<SD-3SC>
Indicator (e.g., RM-5003)
Power supply(+)
CommonSignal (+)

Secure shielded cable with clamp.
GD-3
Connect the shield to thegrounding bolt on the chassis

71 / 1754. Installation

4-7 Connecting the power and signal cables

4-7-5 Connecting cables to the terminal plate
Strip the cable to the specified length and connect to the cable wire insertion holes on the terminal plate.

<Terminal plate specifications> Rated voltage: 300 V AC
 Rated current: 10 A
Specifications will vary depending on the cable used.

<Connecting conditions> Cable used: 0.25 mm2 - 2.5 mm2
 Maximum sheathing external diameter: 4.1 mm
 Stripped wire (conductor) length: 8 mm - 9 mm (9 mm - 10 mm for SD-3 TN1 only) Connecting tool: Flathead screwdriver (blade tip 2.5 mm × 0.5 mm) or operating lever (provided)

CAUTIONBe sure to strip the cable to the specified (conductor) length.
 Conduction faults or overheating may result if the stripped wire (conductor) length is too short and thewire is clamped incorrectly.
 Conduction faults or overheating may result if the stripped wire (conductor) length is too short and thewire sheathing is clamped.
 An insulation failure or short circuit may result if the stripped wire (conductor) length is too long and thewire is exposed.
 Make sure the wire does not splay. An insulation failure or overheating may result if the wire splays wheninserted.
 To avoid the above, if the stripped wire is stranded wire cable, we recommend using a bar terminal(ferrule).
9 mm - 10 mm<Compatible rod terminal>
If you use rod terminals, use the following item: Rod terminal (ferrule): Model 216 series (manufactured by WAGO)
 Crimping tool: Model Variocrimp 4 (206-1204) (manufactured by WAGO)

CAUTION Be sure to use the specified rod terminals. We cannot guarantee performance if you use rod terminals
other than those specified.

72 / 1754. Installation

4-7 Connecting the power and signal cables<Connecting cables to terminal plate>
To connect cables to the terminal plate, use the operating lever provided as a standard accessory or a flatheadscrewdriver (blade tip 2.5 mm × 0.5 mm).
The operating lever provided as a standard accessory cannot be used when connecting power and signal
cables to TN1 on the SD-3. Use a flathead screwdriver in this case.

CAUTION Be sure to use the correct tools.
 As a rule, only one cable can be connected to each wire insertion hole.
 If a cable is inserted into the screwdriver slot, the conductor may not make contact, resulting in
conduction faults or overheating.

When using the operating lever provided as a standard accessory, connect the cable to the terminal plate as
follows.
1

Hook the operating lever on to the screwdriverslot (rectangular hole) in the terminal plate as
shown in the figure to the right.

2

Push the operating lever with your finger to pushdown the spring inside the terminal plate.

Screwdriver slot

Operatinglever

3

While continuing to press the operating lever, insert
the cable into the wire insertion hole (round hole)until it contacts the end.

4

Release the operating lever.
The cable is now connected to the terminal plate.
Gently pull on the cable to confirm that it is correctly connected.
Avoid pulling with excessive force.

73 / 175

Wire insertion
hole
Cable

4. Installation

4-7 Connecting the power and signal cables

When using a flathead screwdriver to connect to TN1 on the SD-3, connect the cable to the terminal plate as
follows:1

Insert the flathead screwdriver into thescrewdriver slot (rectangular hole) in the terminal
plate as shown in the figure to the right.

Flatheadscrewdriver
Screwdriver slot
Wire
insertionhole

2With the flathead screwdriver still being inserted,
insert the cable into the wire insertion hole (roundhole) until it contacts the end.
Cable

3

Release the flathead screwdriver.
The cable is now connected to the terminal plate.
Gently pull on the cable to confirm that it is correctly connected.
Avoid pulling with excessive force.

74 / 1754. Installation

4-8 Mounting the sensor

4-8 Mounting the sensor
Mount the sensor on to the main unit (SD-3) or remote sensor head (GD-3).
1

Remove suction cap, splash guard, and filter, if fitted.

2

Unscrew the single M4 bolt securing the sensor guard.
Use a hex key wrench (2 across flats) to unscrew the M4
hex socket set screw.

Sensor guard
Hex key wrench

3

Rotate and remove the sensor guard.
Remove using a hex key wrench (8 across flats) or
wrench.

4

Pull out and remove the sensor, if fitted.

SensorSensor guard
Hex key
wrench5Match the main unit connector and sensor connector
and fully insert the sensor.
Push the sensor all the way into the main unit connector.
Avoid forcibly turning or pushing in the sensor wheninserting it, as this may damage the main unit. Take carewhen inserting.

Main unit connector

75 / 1754. Installation

6

4-9 Alarm relay setting (option)

Confirm that the sensor is fully inserted.

SensorSensor is not fully
inserted.

7

Attach the sensor guard to the main unit.
Attach using a hex key wrench (8 across flats) or wrench.

8

Use the single M4 hex socket set screw to secure the sensor
guard in place.
Use a hex key wrench to tighten the M4 hex socket set screw.

*The diagram illustrates the SD-3. The mounting method for the remote sensor
head (GD-3) is identical.

Sensorguard

Hex key wrench

CAUTION Depending on the sensor, some fluctuation of the reading may occur if foreign objects are introduced
while replacing the sensor.

4-9 Alarm relay setting (option)
The product can be operated as a standalone unit by setting an alarm relay.
By default, the alarm relay is set to a de-energized state.

WARNING If using a supply voltage of 30 V AC or 42.4 V DC or greater, either fit protective tubing to the cable or use
a double insulation cable.

76 / 1754. Installation

4-9 Alarm relay setting (option)

CAUTION Note that recurring use with the alarm relay contacts normally closed may result in the contacts seizing
due to minute vibrations.
 Connect the alarm relay cable and sensor before turning on the power to the product.
To set the alarm relay, connect the alarm unit cables to the TN2 (Relay1:ALARM1), TN3 (Relay2:ALARM2), andTN4 (Relay3:FAULT) terminal plates on the main unit (SD-3/SD-3SC).
1

Unscrew the M4 hex socket set screw on the main
unit cover, then rotate the cover counterclockwise
to remove.
Use a hex key wrench (2 across flats) to unscrew theM4 hex socket set screw.
Be careful to avoid dropping the cover while unscrewing
and removing it.

Lug on housing

2

Unscrew the two M3 screws securing the display
unit.

3

Pull out the display unit and hang on the lug on the
housing.
The display unit is connected to the terminal plate unit
by a flat cable. Pulling with excessive force may
disconnect the cable.
During the removal process, avoid pulling on the display
unit with excessive force.

Lug on housing

Display unit

77 / 1754. Installation

4-9 Alarm relay setting (option)

4

Pull out the terminal plates (TN2 (Relay1:ALARM1),
TN3 (Relay2:ALARM2), and TN4 (Relay3:FAULT)) fromthe terminal plate board.

5

Connect the alarm unit wires to the corresponding
terminals on the detached terminal plates.
Use either terminal 1 (N.O.) or terminal 3 (N.C.) on theterminal plate.
TN3
For information on how to connect cables to the terminal
plates, refer to ‘4-7-5 Connecting cables to the terminal
plate’.
Common for TN2 (Relay1:ALARM1), TN3(Relay2:ALARM2), and TN4 (Relay3:FAULT)(Default (normally de-energized) terminal assignment)
Terminal
No.
1
2
3

TN2

TN4

Cable connection
N.O.
CommonN.C.

N.O.: Normally open
N.C.: Normally closed

Conductor
Insulation
SheathingRecommended insulation length: 120 - 130 mm

6

Mount the terminal plates (TN2 (Relay1:ALARM1), TN3(Relay2:ALARM2), and TN4 (Relay3:FAULT)) on theterminal plate board.
Adjust the cable position so that no load is applied to theterminal plates.

7

Return the display unit to its original position andsecure with the two M3 screws.
Take care not to trap the cable here.

8

Rotate the cover clockwise to attach and secure withthe single M4 hex socket set screw.
Use a hex key wrench (2 across flats) to tighten the M4
hex socket set screw.
Take care not to trap the cable when attaching the cover.
Rotate the cover clockwise until it moves no further tosecurely fasten in place.

*The diagram illustrates the SD-3. The connection method for the SD-3SC is
identical.

78 / 1754. Installation

4-10 Mounting the splash guard

4-10 Mounting the splash guard
When using a silicone removal filter or activated carbon filter, fit the filter inside the splash guard before mounting
the splash guard.
1

2

When using a silicone removal filter or activatedcarbon filter, remove the splash guard cover, fit thefilter inside the splash guard, and reattach the cover.
This step is required only when using a silicone removal
filter or activated carbon filter.

Cover

FilterMount the splash guard over the guard on the mainunit, then turn clockwise to secure into place.
Mount the splash guard securely by rotating clockwise
until it will not rotate any further.
Avoid rotating with excessive force.

Guard

Splash guard*The diagram illustrates the SD-3. The mounting method for the remote sensor head (GD-3) is identical.

NOTE
 Three different splash guard types are available: for the IRF sensor; forthe combustible gas sensor; and for the ESF sensor.
The corresponding identification number is engraved on theunderside of each splash guard.
Identification
・ IRF sensor identification number:
1
number・ Combustible gas sensor identification number: 2
・ ESF sensor identification number:3
 The splash guards are compatible with the following SD-3 and GD-3 models:<for combustible gas<for IRF sensor><for ESF sensor>
sensor>SD-3RI
SD-3NC
SD-3ECGD-3RI
SD-3GH
SD-3ECS
SD-3GHS
SD-3ECB
SD-3SP
GD-3ECGD-3NCGD-3ECS
GD-3GH
GD-3ECB
GD-3GHS
GD-3SP

79 / 1754. Installation

4-11 How to install the lightning arrester

4-11 How to install the lightning arrester
SD-3 can connect a simple lightning arrester. Be sure to use the specified model and connect it to theterminal block for power and signal.

＜Using 3-core cable＞
Terminal
No.

Power/signal cableconnection

1
2

Power supply (+)
Common(power supply (−),
signal (−))
Signal (+)－

3
GroundConnectionof lightning
arrester
Blue
Brown

Power and signal
terminal plate(The numbers are
terminal numbers.)

Black
Yellow/Green＜Using 4-core cable＞
Terminal
No.

Power/signal cableconnection

12
3
4GroundPower supply (+)
Power supply (−)
Signal (+)
Signal (−)－

Connectionof lightning
arrester
Blue
Brown
Black
White
Yellow/Green

GroundNOTE [Designated lightning arrester]
Type：TP48-3-N-NDI
TP48-4-N-NDI*When connecting a lightning arrester, use connection port 2 or 4. If a lightning arrester other than thespecified one is used, the explosion-proof performance will not be satisfied.
 When installing a surge arrester, check its operation before using it. Also, surge arresters cannot remove
all surge voltages.

CAUTION Only ATEX and IECEx specifications are applicable.
 Discontinue use if operational problems occur.

80 / 175

5. Usage Instructions

5-1 Preparations for startup

5

Usage Instructions
5-1 Preparations for startup
Carry out the following checks before connecting the power supply. Failure to perform these checks may resultin electric shock or damage to the product.
 Check to confirm that the product is grounded.
 Check to confirm that external wiring is correctly connected.
 Check to confirm that the power supply voltage is within the rated range.
 External contacts may operate while adjustment is under way. Take precautions to prevent any external
effects from the contacts operating.

<How to read display examples>
LED display examples are shown as follows in this operating manual.
The display examples are for cases in which the detection target gas is combustible gas (display units: %LEL
lit).
PW

A1

A2

PPM %LEL %F

PW:POWER (Power lamp)lit (green) /A1:

ALM1 (Alarm lamp)lit (red)A2:

ALM2 (Alarm lamp)lit (red)F:

FAULT (Fault lamp)lit (yellow)

PPM:

Units lamplit (green)%LEL: Units lamplit (green)%:lit (green)

Units lamp

81 / 175

flashing (green)5. Usage Instructions

5-2 Startup

5-2 Startup
CAUTION Check to confirm that the product has been correctly installed before turning on the power supply (24 V
DC).

Turn on the power supply (24 V DC) and start the product.
The product takes approximately 25 seconds before switching to detection mode after the power is turned on.
System checks, alarm cutoff, and other initialization occurs during this time.
The display automatically changes as follows after the power is turned on.
The product is normally used in detection mode after the power is turned on.

RI

NC

EC

All litGH

Initialization display (approx. 25 seconds)

Detection modeSP
All lit

Initialization display(approx. 25 seconds)

Initialization
display

Detection mode

(The number indicates
the warmup time)

CAUTION Never turn off the power while initialization is underway. The internal memory is read during initialization.
 A specific warmup is required for each sensor type at startup and after sensor replacement. Allow the
product to warm up for the specified time. Expected warmup completion times for the semiconductor type(SGF) and hot-wire semiconductor type (SHF) sensors are indicated after initialization. Alarm activationand output signals will be unstable during warmup. Notify the relevant department beforehand to avoid
conditions that may lead to errors.
 Perform calibration once warmup is complete.

82 / 175

5. Usage Instructions

5-3 Basic operation flow

5-3 Basic operation flow
After the power is turned on, the product operates as follows when you press the MENU/ESC key:
<Detection mode>
MENU/ESC key(long press)
Power is turned backon after recovery.
MENU/ESC key(long press)<First alarm><User mode><Second alarm><Maintenance mode><Fault alarm>

WARNING Switching from detection mode to user mode or maintenance mode in an alarm state will cancel thealarm.

NOTE
 The LEDs on the product comprise a five-digit seven-segment display. Setting details are displayed as
item numbers.
When setting in user mode or maintenance mode, select the item number corresponding to the details tobe set. (Refer to ‘5-5-1 User mode setting items’ and ‘7-2-1 Maintenance mode setting items’.)

83 / 175

5. Usage Instructions

5-4 Operating procedure

5-4 Operating procedure
The product is operated using the control key.
Use the control key to touch the four keys (MENU/ESC key, SET key, ▲ key, and ▼ key) on the front of the
product.
This operating manual refers to the action of touching the individual keys using the control key as “pressing.”<Control key>

CAUTION Do not press the control key forcibly against the glass.

84 / 175

5. Usage Instructions

5-5 User mode

5-5 User mode
Switching to user mode lets you perform zero calibration and check various settings.

CAUTION Do not alter settings unnecessarily. Altering the settings without a proper understanding of the details
may prevent the product from operating correctly.

5-5-1 User mode setting items
Item No.
1-0

Setting item
Version information

LED display

1-1

Zero calibration

Performs zero calibration.
(Refer to ‘5-6 Performing zero
calibration’.)1-2

Setting display

Displays the alarm settings.
(Refer to ‘5-7 Checking settings’.)

1-3

Maintenance mode
selection

Switches to maintenance mode.
(Refer to ‘7-2 Maintenance mode’.)85 / 175

Details
Displays the program version andother information.
This is not normally used by theuser.

5. Usage Instructions

5-5 User mode

5-5-2 Switching to user mode1

Hold down the MENU/ESC key (for approximately threeseconds) in detection mode.

The product switches to user mode.

2

Press the ▲ or ▼ key to select the required item
number, then press the SET key.

Display example: With setting
display selected

The details corresponding to the item number selected are displayed.
Set or display individual items.

3

Once the operation is complete, hold down the MENU/ESC key (for approximately three seconds).
The product switches to detection mode.

WARNING Once the operation is complete, be sure to hold down the MENU/ESC key to return to detection mode.
The product will not detect gases while in adjustment/setting state. If left in user mode, the product willtake 10 hours to return to detection mode. Detection will not be available during this time, posing
hazards.

86 / 175

5. Usage Instructions

5-6 Performing zero calibration

5-6 Performing zero calibration
This performs the zero calibration required to ensure accurate measurement of gas concentrations.
Prepare the zero calibration gas, then connect to the product before starting zero calibration.
For information on zero calibration preparation, refer to ‘7-4-1 Calibration preparation’.

WARNING Before performing zero calibration for the surrounding atmosphere, confirm that the surrounding
atmosphere contains clean air. Performing zero calibration in the presence of miscellaneous gases will
prevent correct calibration and create safety hazards in the event of an actual gas leak.

CAUTION Perform zero calibration after supplying the zero calibration gas and waiting for the reading to stabilize.

1

Press the ▲ or ▼ key in user mode to select [1-1], thenpress the SET key.

2

Introduce the zero calibration gas, then press the SET key.

Zero calibration starts.

3

Check the zero calibration result.
If zero calibration is successful[PASS] is displayed for three seconds before the display automatically
returns to [1-1].
If zero calibration is unsuccessful[FAIL] is displayed for three seconds before the display automatically
returns to [1-1].

87 / 175

5. Usage Instructions

5-6 Performing zero calibration

NOTE If zero calibration is unsuccessful because the zero point ([20.9] (vol%) in the case of oxygen) fluctuatessignificantly around zero, [FAIL] is displayed before the display returns to [1-1]. If this occurs, zero
calibration was not performed.
 [1-1] corresponds to span adjustment for the oxygen deficiency alarm specifications. Introduce clean air
to adjust to [20.9] (vol%). For information on span adjustment, refer to ‘7-4-3 Performing span
adjustment’.

88 / 175

5. Usage Instructions

5-7 Checking settings

5-7 Checking settings
Displays the alarm settings.
Item No.
1-2
1-2.0

1-2.1

Setting item
Setting display
Alarm setting display‐

Remarks
Zero follower setting ON/OFF display:NC

Sensitivity correction ON/OFF display:

EC

EC

This is not normally used by the user.

5-7-1 Checking alarm setpoints
Displays the various alarm settings, including first alarm setpoint, second alarm setpoint, and alarm delay time.

NOTE The zero follower setting ON/OFF display appears only with sensors that rely on the new ceramic(catalytic) or electrochemical detection principle. (Refer to ‘1-2-2 Detection principles and detection target
gases for individual models’.) The sensitivity correction ON/OFF display appears only with sensors that rely on the electrochemical typedetection principle. (Refer to ‘1-2-2 Detection principles and detection target gases for individual models’.)

1

Press the ▲ or ▼ key in user mode to select [1-2], thenpress the SET key.

2

Select [1-2.0], then press the SET key.

3

Check the individual alarm setpoints.
Press the ▲ or ▼ key to toggle between different setpoints.
・ First alarm setpoint display
Displays the first alarm setpoint.

89 / 175

5. Usage Instructions

5-7 Checking settings

・ Second alarm setpoint display
Displays the second alarm setpoint.

・ Alarm delay time
Displays the alarm delay time (in seconds).
(There is not normally a need for end users to change thesesettings.)

・ Zero suppression value display
Displays the positive side suppression value.

・ Zero follower ON/OFF display
Displays whether the zero follower setting is on or off.
(This is not normally used by the user.)・ Sensitivity correction ON/OFF display
Displays whether sensitivity correction is on or off.
(This is not normally used by the user.)Press the ▲ key to return to the first alarm setpoint display.
First alarm setpoint display
4

Press the MENU/ESC key.
Returns to the [1-2.0] display.

NOTE
 The alarm setpoints and zero suppression value can be set in environmental settings 1 in maintenancemode. (Refer to ‘7-5 Setting environmental settings 1’.)90 / 175

5. Usage Instructions

5-8 Shutting down

5-8 Shutting down
To shut down product operation, turn off the power supply (24 V DC) while in detection mode.

WARNING Shutting down product operation may activate an alarm in an upstream (central) system.
 Before shutting down product operation, make sure the INHIBIT setting is enabled (alarm processes are
stopped) in the upstream (central) system. Also check the operation of any devices connected to theexternal output or external contact output terminal of the product to confirm shutting down the power will
not cause problems.
 If using contacts (optional), the contacts may activate when the power supply is turned off.

91 / 175

6. Alarm Activation

6-1 Gas alarm activation

6

Alarm Activation
6-1 Gas alarm activation
6-1-1 Alarm activation
The product issues an alarm when the detected gas or oxygen concentration reaches or exceeds the alarm
setpoint. (Auto reset or self-latching)

NOTE The alarm setpoints (first and second alarms) and alarm pattern (auto reset or self-latching) are set at thefactory before shipping.
 An alarm delay time (default setting: 2 seconds) is set to prevent accidental alarm activation.

<Gas concentration display>
If the reading exceeds the detection range (full scale exceeded), “∩∩∩∩” appears on the LED display.

<Power/alarm lamp display>
The alarms are two-step alarms. The alarm lamps light up when the corresponding alarm setpoint is reached or
exceeded.
The alarm lamps (ALM1 and ALM2) light up in red. The display appears as follows.
The power lamp (POWER) remains lit in green.
<First alarm><Second alarm>
Alarm lamp (ALM1)
Alarm lamp (ALM2)

Alarm lamp (ALM1)

ALM1 lit (red)ALM1 and ALM2 lit (red)NOTE If the alarm pattern is set to self-latching, the alarm will continue even when the gas concentration falls
below the alarm setpoint.
Operate the keys to cancel the alarm state after confirming that there is no gas present in the vicinity.

92 / 175

6. Alarm Activation

6-1 Gas alarm activation

6-1-2 Contact operation (auto reset)
If auto reset is set, the contacts will activate when the gas concentration reaches or exceeds the alarm setpoint.
The contact operation is automatically reset when the gas concentration falls below the alarm setpoint.

<Alarm pattern (H-HH)>
Normal

Alarm

Reset

Gas concentration■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact<Alarm pattern (L-H)>
Normal

Alarm

Reset

Alarm

Reset

Gas concentration■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact<Alarm pattern (L-LL)>(Oxygen deficiency alarm)
NormalAlarm

Gas concentration■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact

93 / 175

Reset6. Alarm Activation

6-1 Gas alarm activation

6-1-3 Contact operation (self-latching)
If self-latching is set, the contacts will activate when the gas concentration reaches or exceeds the alarm
setpoint.
The contact operation is automatically reset when the gas concentration falls below the alarm setpoint after
resetting.
The alarm lamps flash when an alarm occurs. The lamps stop flashing and remains constantly lit when reset.
Then, the lamps go out when the gas concentration falls below the alarm setpoint.

NOTE To cancel an alarm, press the MENU/ESC key, SET key, ▲ key, or ▼ key in detection mode.

<Alarm pattern (H-HH)>
Normal

Alarm

Reset

Gas concentration

Reset

Reset

■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact
Reset■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact
Reset■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact
Reset■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact

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6. Alarm Activation

6-1 Gas alarm activation<Alarm pattern (L-H)>
Normal

Alarm

Reset

Alarm

Reset

Gas concentration

Reset

Reset

■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact
Reset

Reset

■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact
Reset■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact
Reset■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact

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6. Alarm Activation

6-1 Gas alarm activation<Alarm pattern (L-LL)>(Oxygen deficiency alarm)
Normal

Alarm

Reset

Gas concentration

Reset

Reset

■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact
Reset■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact
Reset■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact
Reset■ ALM1 alarm lamp (red)■ ALM2 alarm lamp (red)■ ALM1 alarm contact■ ALM2 alarm contact

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6. Alarm Activation

6-2 Fault alarm activation

6-1-4 Alarm response
If an alarm is triggered, respond promptly in accordance with the user’s management rules.
The typical procedures are as follows:
Step 1 Check the reading on the product.

CAUTION In the case of momentary gas leaks, the reading may have already dropped by the time the reading ischecked. The reading may also drop while in a temporary alarm state due to factors other than gas
alarms, such as noise or incidental conditions.
Step 2 Keep all individuals out of the monitored zone to ensure safety in accordance with your alarm
control concentrations.
Step 3 If the concentration display continues, close the main valve for the gas involved and confirm
that the gas concentration reading has fallen.
Step 4 Approach the gas leak location and use a portable gas detector to check for the presence of any
remaining gas.

CAUTION To avoid hazards while carrying out this work, assume that the gas is still present and wear theappropriate gear.
Step 5 Once you have determined that no hazard remains, take action to fix the gas leak.

6-2 Fault alarm activation
A fault alarm is triggered if an abnormality is detected in the product.
If a fault alarm occurs, the fault lamp (FAULT) illuminates in yellow, and an error code is displayed as follows:<In case of sensor abnormality>
Fault lamp (FAULT)FAULT lit (yellow)

NOTE
 After the product has successfully recovered from the fault, it will initialize and restart.
 For more information on fault details (error codes) and appropriate corrective action, refer to‘9. Troubleshooting’.
 If a fault alarm occurs, determine the cause and take appropriate action. If the product has problems andfaults occur repeatedly, contact RIKEN KEIKI immediately.

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6. Alarm Activation

6-3 Warning operation

6-3 Warning operation
If the product ambient temperature exceeds the specified operating temperature range, the concentration readout
and warning number [E-27] are displayed alternately.
Gas can still be measured in this state, as this is not a product fault. The external output will also be output in therange 4 mA to 20 mA according to the target gas concentration. The fault lamp will not light up.

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6. Alarm Activation

6-4 External output operation

6-4 External output operation
6-4-1 For target gases other than oxygenMode

4 - 20 mA (output value)

1

Power supply off

0 mA

2

Initialization

Depends on the settings for item 11.
2.5 mA setting: 2.5 mA
4 mA, HOLD, 4 - 20 mA setting: 4 mA

3Detection mode (no alarm)

4 - 20 mA (concentration output)

4

Detection mode (gas alarm)

4 - 20 mA (concentration output)

5

Detection mode (full scale exceeded)

20.5 mA (fixed)

6

Outside operating temperature range

4 - 20 mA (concentration output)

7

Fault alarm

0.5 mA (fixed)

8

Inhibit

Depends on the settings for item 11.
2.5 mA setting: 2.5 mA
4 mA, HOLD, 4 - 20 mA setting: 4 mA

9

Alarm test mode

Output ON setting: 4 - 20 mA (concentration output)
Output OFF setting: 4 mA

10

User mode

Depends on the settings for item 11.
2.5 mA setting: 2.5 mA
4 mA setting: 4 mA
HOLD setting: Retains previous value.
4 - 20 mA setting: 4 - 20 mA (concentration output)

11

Maintenance mode

2.5 mA setting: 2.5 mA
4 mA setting: 4 mA
HOLD setting: Retains previous value.
4 - 20 mA setting: 4 - 20 mA (concentration output)

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6. Alarm Activation

6-4 External output operation<Gas concentration and external output example (with standard range)><4 - 20 mA specification (maintenance output: 2.5 mA setting)>
Detection mode
Maintenance mode

External output
20.5 mA
20 mA

4 mA
2.5 mAGas concentration
0

Zero suppression

Full scale
20 mA output

Full scale over
20.5 mA fixed output

CAUTION The 4 - 20 mA output is already adjusted. When the full scale is exceeded, the output will not exceed
approximately 20.5 mA.
 If the inhibit function is enabled or initialization is underway, the output follows the 4 - 20 mA output setting
in maintenance mode. Special care is required when starting the product or after altering specifications.
 Make sure you fully understand the operation details. Take appropriate precautions where necessary to
prevent false alarms on the receiving side.
 When the suppression function is canceled, the signal will be linearly output to 4 mA (equivalent to
0 %LEL).
 When the minus suppression function is canceled, the signal will be linearly output to 3.2 mA (equivalent
to −5 %LEL).

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6. Alarm Activation

6-4 External output operation<Gas concentration and external output example (with double range)> NC
Two display ranges (L range and H range) are provided when using a new ceramic type (catalytic type) sensor.
The display automatically switches to the H range if the combustible gas concentration reading exceeds the fullscale of the L range. The range also automatically switches back to the L range when the gas concentration
drops below the full scale of the L range.
For example, when the target gas is isobutane, readings between 0 and 2,000 ppm appear in the L range andthe display switches to the H range for readings between 12.0 and 100.0 %LEL.
<4 - 16 mA (L range)/16 - 20 mA (H range) setting>External output
20.5 mA
20 mA

Detection mode
Maintenance mode

16 mA

4 mA
2.5 mAH range

0 Zero suppression

Full scale
20 mA output

Gas concentration
Full scale over
20.5 mA fixed output<4 - 20 mA (L range)/22 mA (H range) setting>External output
20.5 mA
20 mA

Detection mode
Maintenance mode

4 mA
2.5 mA
L range0

Zero suppression

Full scale
20 mA output

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Gas concentration
H range20.5 mA fixed output

6. Alarm Activation

6-4 External output operation<4 - 20 mA (H range) setting>External output

Detection mode
Maintenance mode

20.5 mA
20 mA

Switchover point mA
Full scale over
20.5 mA fixed output

4 mA
2.5 mA
L range0

H rangeZero suppression

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Full scale
20 mA output

Gas
concentration

6. Alarm Activation

6-4 External output operation

6-4-2 When the target gas is oxygenMode

4 - 20 mA (output value)

1

Power supply off

0 mA

2

Initialization

Depends on the settings for item 11.
2.5 mA setting: 2.5 mA
4 mA, HOLD, 4 - 20 mA setting: 4 mA※

3Detection mode (no alarm)

4 - 20 mA (concentration output)

4

Detection mode (gas alarm)

4 - 20 mA (concentration output)

5

Detection mode (full scale exceeded)

20.5 mA (fixed)

6

Outside operating temperature range

4 - 20 mA (concentration output)

7

Fault alarm

0.5 mA (fixed)

8

Inhibit

Depends on the settings for item 11.
2.5 mA setting: 2.5 mA
4 mA, HOLD, 4 - 20 mA setting: 4 mA※

9

Alarm test mode

Output ON setting: 4 - 20 mA (concentration output)
Output OFF setting: Retains previous value.

10

User mode

Depends on the settings for item 11.
2.5 mA setting: 2.5 mA
4 mA setting: 4 mA※
HOLD setting: Retains previous value.
4 - 20 mA setting: 4 - 20 mA (concentration output)

11

Maintenance mode

2.5 mA setting: 2.5 mA
4 mA setting: 4 mA※
HOLD setting: Retains previous value.
4 - 20 mA setting: 4 - 20 mA (concentration output)*ESF (detection target gas: oxygen 0 to 25 vol%) is air equivalent (20.9 vol% = 17.4 mA).

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6. Alarm Activation

6-4 External output operation

CAUTION<With analog transmission (4 - 20 mA)> The 4 - 20 mA output is already adjusted. If the full scale is exceeded, the output will not exceed 20.5 mA.
 If the inhibit function is enabled or initialization is underway, the output follows the 4 - 20 mA output setting
in maintenance mode. Note that the output may become low (e.g., 2.5 mA during initialization) whenusing ESF (detection target gas: oxygen). Special care is required when starting the product or after
altering specifications.
 Make sure you fully understand the operation details and take appropriate precautions where necessary(e.g., setting to skip state) to prevent false alarms on the receiving side.
 Particular care is required in the following situations:
Analog transmission
Examples where care is required
4 - 20 mA specifications
A false alarm may occur upstream (L alarm) if
Using ESF (detection target gas: oxygen)
2.5 mA is output in maintenance mode or if the(L-LL, L-H)
inhibit function is enabled.
If changed from another principle (H-HH), 4 mA
Changed to ESF specifications(equivalent to zero concentration) is output until the(detection target gas: oxygen 0 - 25 vol%)change is confirmed (until [C-02] is displayed).
If changed from 0 to 25 vol% (L-LL, L-H), 17.4 mA
Changed from ESF specifications(equivalent to approximately 84 %FS) is output until(detection target gas: oxygen 0 - 25 vol%)the change is confirmed (until [C-02] is displayed).

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6. Alarm Activation

6-4 External output operation<Gas concentration and external output example>
0 - 25 vol% (oxygen deficiency alarm specification)
External output
20.5 mA
20 mA
Detection mode
Maintenance mode

17.4 mA

4 mA
2.5 mAGas concentration
0
Suppression value

Full scale
20 mA output

Full scale over
20.5 mA fixed output

CAUTION The 4 - 20 mA output is already adjusted. When the full scale is exceeded, the output will not exceed
approximately 20.5 mA.
 If the inhibit function is enabled or initialization is underway, the output follows the 4 - 20 mA output setting
in maintenance mode. Special care is required when starting the product or after altering specifications.
 Make sure you fully understand the operation details. Take appropriate precautions where necessary to
prevent false alarms on the receiving side.
 When the minus suppression function is canceled, the signal will be linearly output to 3.2 mA (equivalent
to −5 %LEL).

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6. Alarm Activation

6-5 Functions to ensure correct alarm activation

6-5 Functions to ensure correct alarm activation
6-5-1 Zero suppression function
The sensors used in the product are susceptible to the effects of ambient fluctuations (e.g., temperature andhumidity characteristics) and interference gases (interference characteristics), which affect the readings givenby the product. Therefore, readings may fluctuate around zero levels even under normal conditions.
The zero suppression function is designed to minimize the effects of these ambient fluctuations and interference
gases around the zero level. Use this function to suppress reading fluctuations below the preset value to give azero reading (or [20.9] (vol%) for oxygen).
<Zero suppression function disabled><Zero suppression function enabled>

The reading fluctuates around the zerolevel.

Displays zero up to the preset value.

NOTE The standard preset value for the zero suppression function differs depending on sensor specifications.
 When the detection target gas is oxygen, enabling the zero suppression function will give a reading of[20.9] (vol%) for fluctuations in the vicinity of 20.9 vol% up to the preset value. Note that the standard
preset value for the zero suppression function is ±0.5 vol% (with respect to 20.9 vol%) when thedetection target gas is oxygen.
 In user mode and maintenance mode, this function is disabled and reading fluctuations below the preset
value are apparent.
 The zero suppression type is initially set to [CUT]. For information on how to change the zero
suppression type, refer to ‘7-5-9 Zero suppression type setting’.
 The positive zero suppression value can be set within the range of 0 to 2/3 of the first alarm setpoint (ifthe first alarm setpoint is 25%LEL, up to 16%LEL). The negative zero suppression value can be set
within the range of 0 to 5 % of full scale +1 digit (if the full scale is 100%LEL, -5%LEL+1 digit). (This is notnormally used by the user.)CAUTION The negative suppression value (below zero) is subject to suppression corresponding to 5 % of full scale.
The error code "E-1" is displayed if the reading falls below 5% of full scale. Accurate gas detection is notpossible in this state. Check to confirm that no miscellaneous gases are present, then perform zero
calibration.

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6. Alarm Activation

6-5 Functions to ensure correct alarm activation

6-5-2 Automatic sensor recognition function
This product features a function that automatically recognizes the sensor after a sensor is replaced or
specifications have been changed.
The display appears as follows to prevent incorrect mounting if a sensor with a different serial number, detection
principle, or specifications is mounted:<After sensor replacement>
The display appears as follows when the sensor has been replaced with a sensor of the same specifications (e.g.,
detection principle and model)—for example at periodic replacement.
Pressing the MENU/ESC key makes the product recognize the sensor as a new sensor and start up.

If the sensor mounted after replacement has the same or an older manufacturing date than the sensor replaced,the display alternates between [C-01] and [USEd], as follows.
An old sensor may have been mounted by mistake. Check the sensor.

<After changing specifications>
The display appears as follows when the sensor has been replaced with a sensor of different specifications (e.g.,
detection principle and model).
Pressing the MENU/ESC key makes the product recognize the sensor as a sensor with new specifications andstart up.
If you did not intend to change the specifications, the sensor may have been mounted by mistake. Check thesensor.

CAUTION
 Confirming changes in sensor specifications (e.g., detection principal, sensor type, detection target gas,and detection range) when [C-02] is displayed will reflect the changes in the specifications of the productas gas detector.
The following parameters will be reset to their initial values in addition to the alarm setpoints.
Change the parameters in maintenance mode if values other than the initial values are required.
・Alarm delay
・Zero suppression value
・Alarm type Confirming the changes by pressing the MENU/ESC key when [C-02] is displayed will start initializationand switch the operation. The initialization output will also change at the same time.
 Settings such as external output are maintained at their previous settings in maintenance mode.
Particular care is required here.
 The ESF specifications include three different alarm types: L-LL, L-H, and H-HH.
The alarm directions will be reversed for changes from or to ESF (L-LL alarm).

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7. Maintenance

7-1 Maintenance intervals and items

7

Maintenance
The product is an important safety and disaster prevention device.
Perform product maintenance at regular intervals to ensure performance and to improve disaster prevention
and safety reliability.

7-1 Maintenance intervals and items
The following items should be maintained regularly before using the product:• Daily maintenance:
Perform maintenance before commencing work.
• Monthly maintenance: Inspect the alarm circuit (alarm test) once a month.
 Regular maintenance: Check detection accuracy and perform calibration using a calibration gas.
<Recommended calibration interval>
ESF/IRF sensors: At least once every 6 - 12 months
NCF/SGF/SHF sensors: At least once every 4 - 6 months
Perform calibration at least once a year to ensure adequate performance as a safety
device.
Maintenance
item

Maintenance details

Daily
maintenance

Monthly
maintenanceRegularmaintenancePower supply
check

Check to confirm that the power lamp
is lit.

〇〇〇Concentration
display check

Check to confirm that the concentration
reading is zero (or [20.9] (vol%) for
oxygen).
If the reading is offset, perform zero
calibration after confirming that no
miscellaneous gas is present in thevicinity.

〇〇〇

Use the alarm test function to checkthe alarm circuit.
If you use an optional alarm relay,
check the relay at the same time.

－

〇

〇

Calibration

Perform sensitivity calibration using acalibration gas.

－

－

〇

Gas alarm check

Check the gas alarm using a calibration
gas.

－

－

〇

Grounding cablecheck

To ensure EMC performance, check to
confirm that the grounding cableconnection is secure and free ofcorrosion.

－

－

○

Alarm test

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7. Maintenance

7-1 Maintenance intervals and items<Maintenance services>
RIKEN KEIKI provides services related to regular maintenance including calibration, adjustments, and servicing.
Preparing a calibration gas requires dedicated equipment, including gas cylinders of the specified concentrationand gas sampling bags.
Our certified service engineers have expert knowledge of the dedicated tools and products. We recommend
taking advantage of our maintenance service to ensure safe use of the product.
The main details of the maintenance services are as follows. Please contact RIKEN KEIKI for more information.
Service

Service details

Power supply check・ Check the power supply voltage.
・ Check to confirm that the power lamp is lit.
(Confirm that the power lamp (POWER), alarm lamps (ALM1, ALM2), fault lamp
(FAULT), unit lamps (PPM, %LEL, %) are clearly visible on the display.)
・ Check the operation of the UPS (uninterruptible power system), if used.

Concentration
display check

Check to confirm that the concentration reading indicates zero using a zero
calibration gas. Perform zero calibration if the reading is not zero.
With the oxygen deficiency alarm specifications, introduce clean air and check thatthe concentration reading indicates [20.9] (vol%). Perform span adjustment if thereading is offset.

Filter check

Check to confirm that the dust filter is neither contaminated nor clogged.
Replace the filter if the filter is dirty or clogged.

Alarm test

Use the alarm test function to inspect the alarm circuit.
・ Check alarm lamps. (Check the ALM1 and ALM2 operations.)
・ Check external alarms. (Check the buzzer, reset signal, and other external
alarm operations.)

Calibration

Perform sensitivity calibration using a calibration gas.

Gas alarm check

Check the gas alarm using a calibration gas.
・ Check alarms. (Confirm alarm activation when alarm setpoint is reached.)
・ Check delay time. (Check delay time until alarm activation.)・ Check alarm lamps. (Check the ALM1 and ALM2 operations.)
・ Check external alarms. (Check the buzzer, reset signal, and other external
alarm operations.)

Product cleaning
and repair (visualinspection)

Check the product exterior, cover, and interior for dirt and damage. Clean/repair
problem areas.
Replace cracked or damaged parts.

Product operation
check

Operate the keys to check individual functions and parameters.

Consumable part
replacement

Replace degraded components such as sensors and filters.

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7. Maintenance

7-2 Maintenance mode

7-2 Maintenance mode
Switching to maintenance mode lets you perform various tests, zero calibration, and span adjustment andconfigure various settings.

7-2-1 Maintenance mode setting items
Item No.
2-0

Setting item
Test mode

LED display

2-1

Zero calibration

Performs zero calibration.
(Refer to ‘7-4-2 Performing zero
calibration’.)2-2

Span adjustment

Performs span adjustment.
(Refer to ‘7-4-3 Performing span
adjustment’.)

2-3

DisplayThis is not normally used by the
user.

2-4

Environmental settings 1

2-5

Environmental settings 2

Configures settings such as alarm
setpoints, alarm pattern, fault alarm
pattern, zero suppression value, andthe date and time.
(Refer to ‘7-5 Setting environmental
settings 1’.)This is not normally used by the
user.

2-6

Environmental settings 3

Configures settings such as used
contact settings and various external
outputs.
(Refer to ‘7-6 Setting environmental
settings 3’.)

2-7

Communication settings

This is not normally used by theuser.

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Details
Performs the gas test, alarm test,
fault test, LED test, and RAM test.
(Refer to ‘7-3 Performing tests (testmode)’.)

7. MaintenanceItem No.
2-8

Setting item
Factory mode selection

2-9

User mode selection

7-2 Maintenance mode

LED display

Details
This is not normally used by theuser.

Switches to user mode.
(Refer to ‘5-5 User mode’.)7-2-2 Switching to maintenance mode1

Hold down the MENU/ESC key (for approximately threeseconds) in detection mode.

The product switches to user mode.

2

Press the ▲ or ▼ key to select [1-3], then press the SET
key.

The product switches to maintenance mode.

3

Press the ▲ or ▼ key to select the required item number,then press the SET key.

Display example: With
environmental settings 1
selected
The details corresponding to the item number selected are displayed.
Set individual items.

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7. Maintenance4

7-2 Maintenance mode

Once the operation is complete, hold down the MENU/ESC key (for approximately three seconds).
The product switches to detection mode.

WARNING Once the operation is complete, be sure to hold down the MENU/ESC key to return to detection mode.
The product will not detect gases while in adjustment/setting state. If left in maintenance mode, theproduct will take 10 hours to return to detection mode. Detection will not be available during this time,posing hazards.

NOTE If the password setting is enabled, the password must be entered to access maintenance mode.
 The password is set in advance by RIKEN KEIKI.
If you are unsure, contact RIKEN KEIKI.

<Switching from maintenance mode to user mode>1

Press the ▲ or ▼ key in maintenance mode several times
to select [2-9], then press the SET key.

2

Press the SET key.

The product switches to user mode.

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7. Maintenance

7-3 Performing tests (test mode)

7-3 Performing tests (test mode)
Test mode is used for performing various tests, such as gas tests and alarm tests.
Item No.
2-0
2-0.0
2-0.1
2-0.2
2-0.3
2-0.4

Setting item
Test mode
Gas test
Alarm test
Fault test
LED test
RAM test

7-3-1 Performing gas test
Perform a gas test.
Before starting the gas test, prepare the gas to be used and connect to the product.
For information on gas test preparation, refer to ‘7-4-1 Calibration preparation’.

WARNING Depending on the settings, contact and gas concentration outputs may be activated during gas testing,even in maintenance mode. Take care during gas testing.

1

Press the ▲ or ▼ key in maintenance mode several times
to select [2-0], then press the SET key.

2

Select [2-0.0], then press the SET key.

3

Introduce the gas to be used in the gas test.

4

Shut off the gas test gas once the gas concentration
reading has stabilized.

5

Once the reading has returned to [0.0] (or [20.9] (vol%) for
oxygen), press the MENU/ESC key.
Returns to the [2-0.0] display.

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7. Maintenance

7-3 Performing tests (test mode)

7-3-2 Performing alarm test
Test to check whether an alarm is triggered when the reading reaches the alarm setpoint.

WARNING Depending on the settings, contact and gas concentration outputs may be activated during alarm testing,even in maintenance mode. Take care during alarm testing.

NOTE The procedure in step 3 is required even if the product is a no alarm relay model. Note that the contact
will not operate even when [on] is selected.

1

Press the ▲ or ▼ key in maintenance mode several times
to select [2-0], then press the SET key.

2

Press the ▲ or ▼ key to select [2-0.1], then press the SET
key.

3

Press the ▲ or ▼ key to select [oFF] or [on], then press the
SET key.
Select [on] if the setting for the contact used is alarm only or
alarm or fault, or [oFF] if the setting is other than those.

4

Press the ▲ or ▼ key to increase or decrease the reading.

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7. Maintenance5

7-3 Performing tests (test mode)

Check to confirm that an alarm is triggered.
The first alarm is triggered when the reading reaches the firstalarm setpoint.
The alarm lamp (ALM1) lights up (red) when the first alarm istriggered.

The second alarm is triggered when the reading reaches thesecond alarm setpoint.
The alarm lamps (ALM1 and ALM2) light up (red) when thesecond alarm is triggered.

6

Once the alarm test is complete, press the MENU/ESC key.
Returns to the [2-0.1] display.

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Alarm lamp
(ALM1)

Alarm lamp
(ALM1)

Alarm lamp
(ALM2)

7. Maintenance

7-3 Performing tests (test mode)

7-3-3 Performing fault test
Test to check whether an alarm is triggered when a fault occurs in the product.

WARNING Depending on the settings, contact and gas concentration outputs may be activated during fault testing,even in maintenance mode. Take care during fault testing.

1

Press the ▲ or ▼ key in maintenance mode several times
to select [2-0], then press the SET key.

2

Press the ▲ or ▼ key to select [2-0.2], then press the SET
key.

3

Press the ▲ or ▼ key to select [on], then press the SET
key.

4

Check to confirm that a fault alarm is triggered.
The fault lamp (FAULT) lights up (yellow) when a fault alarm istriggered.

5

Once the fault test is complete, press the ▲ or ▼ key toselect [oFF], then press the SET key.
The fault alarm is cleared. The fault lamp (FAULT) goes out.
Fault alarms can also be cleared by pressing the MENU/ESC key.

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Fault lamp
(FAULT)7. Maintenance

7-3 Performing tests (test mode)

7-3-4 Performing LED test
Perform an LED display test.
1

Press the ▲ or ▼ key in maintenance mode several times
to select [2-0], then press the SET key.

2

Press the ▲ or ▼ key to select [2-0.3], then press the SET
key.

3

Press the ▲ or ▼ key to select [on], then press the SET
key.

4

Check to confirm that all LEDs light up.

5

Once the LED test is complete, press the ▲ or ▼ key toselect [oFF], then press the SET key.
The LED test ends.
The LED test can also be ended by pressing the MENU/ESC key.

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7. Maintenance

7-3 Performing tests (test mode)

7-3-5 Performing memory test (RAM test)
Perform a memory test.
1

Press the ▲ or ▼ key in maintenance mode several times
to select [2-0], then press the SET key.

2

Press the ▲ or ▼ key to select [2-0.4], then press the SET
key.

3

Press the SET key.

The memory test starts.

3

Check the memory test result.
No problems with memory:[PASS] appears.

Problems with RAM:
[F-rA] appears.

Problems with ROM:
[F-rO] appears.

Problems with both RAM and ROM:
[F-rA] and [F-rO] are displayed alternately.

4

Once you have checked the result, press the SET key.
Returns to the [2-0.4] display.

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7. Maintenance

7-4 Performing calibration

7-4 Performing calibration
7-4-1 Calibration preparation
Before performing calibration (zero calibration and span adjustment), prepare the calibration gas.
Also connect the calibration equipment required to the product before starting.
 Zero calibration gas
 Span adjustment gas (in gas sampling bag or gas can)
 Gas sampling bag for exhaust gas
 Calibration adapter or splash guard<List of adjustment jigs>
Item nameCalibration
adapter
Pump
Flowmeter
Stopwatch

PipingApplicable specifications
For IRF sensors
Part No.: 4283 9011 00
For NCF/SGF/SHF sensors
Part No.: 4283 9012 70
For ESF sensors
Part No.: 4283 9013 40
One that can provide a flow rate of 0.5 mL or greater
Explosion-proof specifications
Measures tolerances to 0.1 ml.
Has passed regular inspection.
Has passed regular inspection.
Material: PolyurethaneInternal diameter: 4 mm
For general combustible gases
Pipe length between gas and adapter:
Within 1 m
Material: Teflon
Internal diameter: 4 mm
For organic solvents
Pipe length between gas and adapter:
Within 1 m
Material: Teflon
Internal diameter: 4 mm
For strongly adsorptive gases
Pipe length between gas and adapter:
Within 10 cm<Zero calibration gas>
 The zero calibration gas is a gas for calibrating the zero point. The ambient air can be used as the zero
calibration gas if there are no interfering impurities or target gases present. For O2 and CO2 sensors,
nitrogen (N2) is used.

<Span adjustment gas>
 The span adjustment gas is a gas for calibrating the sensitivity of the sensors during span adjustment. The
span adjustment gas is a gas of known concentration diluted with clean air or nitrogen. For O2 sensors, theoxygen in the ambient atmosphere is used, so a span adjustment gas is not required.
 We recommend calibrating the device using the detection target gas (actual gas calibration). This method ismore accurate than using a replacement gas. Use of a replacement gas for calibration is permissible incircumstances when it is not possible to use actual gas calibration.
 It is necessary to calibrate for methane and hydrogen using only the actual gases. Do not use replacement
gases for calibration.
 Span adjustment must be performed within 24 hours of the most recent valid zero calibration.
 For managing the concentration of calibration gases, we recommend the use of a RIKEN KEIKI portabledetector.
 Contact RIKEN KEIKI.
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7. Maintenance

7-4 Performing calibration

WARNING Span adjustment gases include combustible gases and toxic gases. Never inhale the calibration gas.
Accidental inhalation may be fatal or harmful to health.

<When using the calibration adapter>
NOTE Use a flow rate of 0.5 L/min ± 0.1 L/min when calibrating. Calibration accuracy may be impaired if
calibration is performed using a different flow rate.
 Three types of calibration adapters are used according to the gas detector model: the calibration adapter
for IRF sensors, that for NCF/SHF/SGF sensors, and that for ESF sensors.
Note that the SD-3GHS, the SD-3DGHS, and the GD-3GHS use the IRF sensor adapter as an
exception.
 Leaving the suction cap and calibration adapter attached in a windless state for 10 minutes or more may
cause adsorbed gas to accumulate, which can cause the reading to rise (for oxygen, the pipes andadapter interior become oxygen deficient, causing the reading to fall). If this occurs, push clean air
through to return the reading to zero. Furthermore, as the sensor will be shut off from the atmosphere,
detection will not be possible in this state.

<Using a gas sampling bag>

RI

EC

Product (SD-3)

Flowmeter
Pump
Out
Calibration
adapterGassamplingbag

P

Needle valveIn

120 / 175

To exhaust
port7. Maintenance

7-4 Performing calibration<Using a gas sampling bag>

NC

GH

SP

Product (SD-3)

Calibration adapter
In
FlowmeterGassamplingbag

Pump
To exhaust port

P

Out
Needle valve*The diagram illustrates the SD-3. The connection method for the remote sensor head (GD-3) is identical.

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7. Maintenance

7-4 Performing calibration

RI<Using a gas can>EC

Product (SD-3)

Out

In

<Using a gas can>NC

GHTo exhaust
port

Calibration
adapter

SP

Product (SD-3)

In

Out
To exhaust
port

Calibration
adapter*The diagram illustrates the SD-3. The connection method for the remote sensor head (GD-3) is identical.

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7. Maintenance

7-4 Performing calibration<When using the splash guard>

WARNING Gas response times can be affected when a splash guard is used.
 The gas response time increases and this can increase the time until the alarm occurs.

NOTE
 The calibration adapter is not required when using the splash guard.
 When using the splash guard, calibrate using the following wind speed:Detection principle

Wind speed

Non-dispersive infrared absorption type(infrared type)New ceramic type (catalytic type)Max. 6 m/s

Semiconductor typeHot-wire semiconductor type
Electrochemical typeMax. 1 m/s

 If calibration is unsuccessful, fit the calibration adapter and calibrate again.
 When calibrating adsorptive gas, fit the calibration adapter.
 Use a flow rate of 0.5 L/min ±0.1 L/min when calibrating. Calibration accuracy may be reduced if
calibration is performed using a different flow rate.

<Using a gas sampling bag>

Product (SD-3)

Splash guard

Flowmeter
Pump
Gas
samplingbag

P
Needle valve*The diagram illustrates the SD-3. The connection method is the same for the remote sensor head (GD-3).

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7. Maintenance

7-4 Performing calibration<Using a gas can>Splash guard
In* The diagram illustrates the SD-3. The connection method is the same for the remote sensor head (GD-3).

<When using filters>

WARNING Sensitivity, gas response times, and replacement gas sensitivity can be affected when a filter is attached.
 The gas response time increases when a filter is used, and this can increase the time until the alarm
occurs.

<When using a protective cover>

WARNING Sensitivity, gas response times, and replacement gas sensitivity can be affected when a protective coveris attached.
 The gas response time increases when a protective cover is used, and this can increase the time until thealarm occurs.

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7. Maintenance

7-4 Performing calibration

7-4-2 Performing zero calibration
Gas concentrations cannot be accurately measured unless zero calibration is performed correctly.
Be sure to carry out zero calibration to ensure accurate measurement.
Prepare the zero calibration gas, then connect to the product before starting zero calibration.
For information on zero calibration preparation, refer to ‘7-4-1 Calibration preparation’.

WARNING Before performing zero calibration for the surrounding atmosphere, confirm that the surrounding
atmosphere contains clean air. Performing zero calibration in the presence of miscellaneous gases will
prevent correct calibration and create safety hazards in the event of an actual gas leak.

CAUTION Perform zero calibration after supplying the zero calibration gas and waiting for the reading to stabilize.

NOTE
 Perform zero calibration and span adjustment in the specified order. Sensor characteristics may beaffected if adjustment is not performed in the correct order.
GHF sensors: Perform span adjustment first, followed by zero calibration.
Sensors other than GHF sensors: Perform zero calibration first, followed by span adjustment.

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7. Maintenance

7-4 Performing calibration

1

Press the ▲ or ▼ key in maintenance mode several times
to select [2-1], then press the SET key.

2

Introduce the zero calibration gas, then press the SET key.

Zero calibration starts.

3

Check the zero calibration result.
If zero calibration is successful[PASS] is displayed for three seconds before the display
automatically returns to [2-1].

If zero calibration is unsuccessful[FAIL] is displayed and the display returns to [2-1] when the
SET key is pressed.

NOTE If zero calibration is unsuccessful because the zero point (N2 in the case of oxygen) fluctuatessignificantly around zero, [FAIL] is displayed. If this occurs, zero calibration was not performed.

7-4-3 Performing span adjustment
Perform the span adjustment required to ensure accurate measurement of gas concentrations.
Prepare the span adjustment gas, then connect to the product before starting span adjustment.
For information on span adjustment preparation, refer to ‘7-4-1 Calibration preparation’.

NOTE Dedicated equipment is required for span adjustment. We recommend contacting RIKEN KEIKI torequest the required equipment.

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7. Maintenance

7-4 Performing calibration<With standard range>

CAUTION Perform span adjustment after supplying the span adjustment gas (at a concentration of 1.6 times thealarm setpoint value or 40 % of full scale) and waiting for the reading to stabilize.
 With the oxygen deficiency alarm specifications, introduce clean air to adjust to [20.9] (vol%).
1

Press the ▲ or ▼ key in maintenance mode several times
to select [2-2], then press the SET key.

2

Introduce the span adjustment gas, then press the SET key.
The SET key is disabled if the reading is less than 10 % of fullscale.

3

Press the ▲ or ▼ key to adjust the reading to match theconcentration of the gas introduced, then press the SET
key.

Span adjustment starts.

4

Check the span adjustment result.
If span adjustment is successful[PASS] is displayed, followed by thecalibration concentration upper limit.
If span adjustment is unsuccessful[FAIL] appears.

5

Press the SET key.
Returns to the [2-2] display.

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7. Maintenance

7-4 Performing calibration

NOTE If span adjustment is unsuccessful because the reading fluctuates significantly compared to theconcentration of the gas introduced, [FAIL] appears. If this occurs, span adjustment was not performed.
 If span adjustment was unsuccessful, check whether the correct concentration span adjustment gas was
supplied and confirm that there are no leaks in the gas calibration equipment. If span adjustment was not
performed correctly, repeat span adjustment.
 If span adjustment was performed correctly or if span adjustment fails even when repeated, the gas
sensor may have reached the end of its service life. Turn off the power and contact RIKEN KEIKI.

<With double range> NC

CAUTION Perform span adjustment after supplying the span adjustment gas and waiting for the reading to stabilize.
 For double range span adjustment, perform span adjustment first for the L range, followed by the H range
in succession. If span adjustment was aborted midway, repeat from the L range.

1

Press the ▲ or ▼ key in maintenance mode several times
to select [2-2], then press the SET key.

2

Introduce the span adjustment gas, then press the SET key.
The SET key is disabled if the reading is less than 10 % of fullscale.

3

Press the ▲ or ▼ key to adjust the reading to match theconcentration of the gas introduced, then press the SET
key.

Span adjustment starts for the L range.

4

Check the L range span adjustment result.
・ If L range span adjustment is
successful[PASS] is displayed, followed by
the calibration concentration
upper limit, after which H range
span adjustment automaticallystarts.
・ If L range span adjustment is unsuccessful[FAIL] appears, and the product automatically proceeds to
H range span adjustment.

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7. Maintenance

7-4 Performing calibration

5

Introduce the span adjustment gas, then press the SET
key.
The SET key is disabled if the reading is less than 10 % of fullscale.

6

Press the ▲ or ▼ key to adjust the reading to match theconcentration of the gas introduced, then press the SET
key.

Span adjustment starts for the H range.

7

Check the H range span adjustment result.
・ If H range span adjustment is
successful[PASS] is displayed, followed by
the calibration concentration
upper limit.
・ If H range span adjustment is unsuccessful[FAIL] appears.

8

Press the SET key.
Returns to the [2-2] display.

NOTE If span adjustment is unsuccessful because the reading fluctuates significantly compared to theconcentration of the gas introduced, [FAIL] appears. If this occurs, span adjustment was not performed.
 If span adjustment was unsuccessful, check whether the correct concentration span adjustment gas wasintroduced and confirm that there are no leaks in the gas calibration equipment If span adjustment was
not performed correctly, repeat span adjustment.
 If span adjustment was performed correctly or if span adjustment fails even when repeated, the gas
sensor may have reached the end of its service life. Turn off the power and contact RIKEN KEIKI.

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7. Maintenance

7-5 Setting environmental settings 1

7-5 Setting environmental settings 1
The following items can be set in environmental settings 1:
Item No.
2-4

Setting item

Remarks

Environmental settings 1
2-4.0

Inhibit setting

2-4.1

Alarm setpoint setting

2-4.2

Alarm delay settingThis is not normally used by the user.

2-4.3

Alarm pattern settingThis is not normally used by the user.

2-4.4

Alarm setpoint limiter settingThis is not normally used by the user.

2-4.5

Alarm type settingThis is not normally used by the user.

2-4.6

Fault alarm pattern settingThis is not normally used by the user.

2-4.7

Zero suppression value setting

2-4.8

Zero suppression type setting

2-4.9

Password

2-4.A

Date and time setting

7-5-1 Inhibit setting
Enabling the inhibit setting prevents alarms from being issued externally even when the gas concentration isdisplayed in detection mode. This setting is primarily used when testing and maintaining the product.
The default setting is disabled.
1

Press the ▲ or ▼ key in maintenance mode to select[2-4], then press the SET key.

2

Select [2-4.0], then press the SET key.

3

Press the ▲ or ▼ key to select [oFF] or [on], then press the
SET key.

Returns to the [2-4.0] display.

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7. Maintenance

7-5 Setting environmental settings 1

NOTE
 Enabling the inhibit setting causes the LED display to alternate between [InHI.] and [0.0] (gasconcentration) when in detection mode.

7-5-2 Alarm setpoint setting
Set the gas alarm setpoints (first alarm setpoint and second alarm setpoint).
Set each alarm setpoint within the following range:
Alarm setpointFirst alarm setpoint ([AL1])
Second alarm setpoint([AL2])

Alarm setpoint range
0 - 10 % of full scale (H-HH)
Combustible gas
First alarm setpoint to 60 % of full scale (H-HH)
Other gases
First alarm setpoint to full scale (H-HH)

1

Press the ▲ or ▼ key in maintenance mode to select [2-4],
then press the SET key.

2

Press the ▲ or ▼ key to select [2-4.1], then press the SET
key.

3

Press the ▲ or ▼ key to select [AL1] or [AL2], then press
the SET key.
To set the first alarm setpoint, select [AL1]. To set the second
alarm setpoint, select [AL2].

4

Press the ▲ or ▼ key to set the alarm setpoint, then press
the SET key.

The display returns to [AL1] or [AL2].

NOTE The alarm setpoints can be checked by displaying the settings in user mode. (Refer to ‘5-7-1 Checking
alarm setpoints’.)

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7. Maintenance

7-5 Setting environmental settings 1

7-5-3 Zero suppression value setting
Set the positive and negative zero suppression values.
Set the zero suppression values within the following ranges:
 Positive suppression value setting ([P-SuP]):
0 to 2/3 of first alarm setpoint Negative suppression value setting ([n-SuP]):
0 to 5 % of full scale + 1 digit

NOTE
 For more information on the zero suppression function, refer to ‘6-5-1 Zero suppression function’.

1

Press the ▲ or ▼ key in maintenance mode to select[2-4], then press the SET key.

2

Press the ▲ or ▼ key to select [2-4.7], then press the SET
key.

3

Press the ▲ or ▼ key to select [P-SuP] or [n-SuP], thenpress the SET key.
To set the positive zero suppression value, select[P-SuP]. To set the negative zero suppression value,
select [n-SuP].

4

Press the ▲ or ▼ key to set the zero suppression value,then press the SET key.

The display returns to [P-SuP] or [n-SuP].

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7. Maintenance

7-5 Setting environmental settings 1

7-5-4 Zero suppression type setting
Set the zero suppression type.
Select one of the following: Cut type ([Cut]):
Values that exceed the zero suppression value are displayed unchanged.
 Slope type ([SLOPE]): Values that exceed the zero suppression value are displayed smoothly.
The default setting is cut type ([Cut]).
1

Press the ▲ or ▼ key in maintenance mode to select[2-4], then press the SET key.

2

Press the ▲ or ▼ key to select [2-4.8], then press the SET
key.

3

Press the ▲ or ▼ key to select [Cut] or [SLOPE], thenpress the SET key.

The display returns to [2-4.8].

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7. Maintenance

7-5 Setting environmental settings 1

7-5-5 Password setting
Set a password for accessing maintenance mode.
If you enable password setting, the product will display a password input screen to access maintenance mode.
The default setting is enabled.

NOTE The password is set beforehand by RIKEN KEIKI.
If you are unsure, please contact RIKEN KEIKI.

1

Press the ▲ or ▼ key in maintenance mode to select[2-4], then press the SET key.

2

Press the ▲ or ▼ key to select [2-4.9], then press the SET
key.

3

Press the ▲ or ▼ key to select [on] or [oFF], then press the
SET key.

The display returns to [2-4.9].

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7. Maintenance

7-5 Setting environmental settings 1

7-5-6 Date and time setting
Sets the date and time (year, month, date, hours, and minutes) for the internal clock.
1

Press the ▲ or ▼ key in maintenance mode to select [2-4],
then press the SET key.

2

Press the ▲ or ▼ key to select [2-4.A], then press the SET
key.

3

Press the ▲ or ▼ key to set the last two digits of the year,
then press the SET key.
The selected item (last two digits of the year) flashes.

4

Press the ▲ or ▼ key to set the month, then press the SET
key.
The selected item (month) flashes.

5

Press the ▲ or ▼ key to set the date, then press the SET
key.
The selected item (day) flashes.

6

Press the ▲ or ▼ key to set the hours (24-hour format),then press the SET key.
The selected item (hour) flashes.

7

Press the ▲ or ▼ key to set the minutes, then press the
SET key.
The selected item (minutes) flashes.

Returns to the [2-4.A] display.

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7. Maintenance

7-6 Setting environmental settings 3

7-6 Setting environmental settings 3
The following items can be set in environmental settings 3:
Item No.
2-6

Setting item

Remarks

Environmental settings 3
2-6.0

Used contact settingThis is not normally used by the user.

2-6.1

Energized/de-energized settingThis is not normally used by the user.

2-6.2

Maintenance external output settingThis is not normally used by the user.

2-6.3

External output adjustment(4 - 20 mA)

This is not normally used by the user.

2-6.4

Alarm test external output

This is not normally used by the user.

2-6.5

Fault alarm external output settingThis is not normally used by the user.

2-6.6

Double range external output settingNC

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7. Maintenance

7-6 Setting environmental settings 3

7-6-1 Double range external output setting

NC

Sets the double range external output range. (Refer to <Gas concentration and external output example (withdouble range)> in ‘6-3 External output operation’.)Select one of the following: 4 - 20 mA (L range)/22 mA (H range) ([L4-20])
 4 - 20 mA (H range) ([H4-20])
 4 -16 mA (L range)/16 - 20 mA (H range) ([4-16])
The default setting is 4 - 16 mA (L range)/16 - 20 mA (H range) ([4-16]).

NOTE
 The double range external output setting can be set only with sensors that rely on the new ceramic
detection principle. (Refer to ‘1-2-2 Detection principles and detection target gases for individual models’.)

1

Press the ▲ or ▼ key in maintenance mode to select [2-6],
then press the SET key.

2

Press the ▲ or ▼ key to select [2-6.6], then press the SET
key.

3

Press the ▲ or ▼ key to select [4-16], [L4-20], or [H4-20],
then press the SET key.

Returns to the [2-6.6] display.

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7. Maintenance

7-7 Parts replacement

7-7 Parts replacement
7-7-1 Sensor replacement
A functional check by a qualified maintenance engineer (or similarly qualified technician) is required after sensor
replacement. To ensure safety and the stable operation of the product, request checking by a qualified
maintenance engineer. Contact RIKEN KEIKI to request checking.

<Sensor replacement intervals>
Sensorreplacement
interval

Gas types

ChemicalformulaDetection
concentration

IRF

－

－

－

5 years

NCF

－

－

－

3 years

SHF

－

－

－

3 years

Sensor model

SGF

－

－

－

3 years

*1

－

－

－

3 years

*2

ESF-B

－

－

－

3 years*5

ESF-C*3－－－

3 years

*4

－

－

－

3 years

ESF-A

ESF-X

*1: ESF-A refers to the type of sensor starting with “ESF-A”.
*2: ESF-B refers to the type of sensor starting with “ESF-B”.
*3: ESF-C refers to the type of sensor starting with “ESF-C”.
*4: ESF-X refers to the type of sensor starting with “ESF-X”.
*5: 3 years for use in a room temperature environment, and 2 years for use under other conditions.

CAUTION Be sure to turn OFF the power supplied to the sensor before replacing the sensor.
 Refer to ‘4-8 Mounting the sensor’ for instructions on how to mount the sensor.
 Perform zero calibration and span adjustment after replacing the sensor.
 The sensor can be replaced in zones classified as hazardous without turning off the main unit power
supply.
 If the same type of sensor (the same part number) was previously installed, the particular configurationsof the device (detection target gas, measurement range, alarm setpoints, zero suppression, etc.) aremaintained. In other cases, the default factory settings of the new sensor are uploaded, overwriting thecurrent configurations. The sensor is recognized by the automatic sensor recognition function. Refer to ‘65-2 Automatic sensor recognition function’ for information on the automatic sensor recognition function.
 Use the “Sensor replacement” item from the sensor replacement function menu to replace the sensor
without triggering a fault signal on the main unit.

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7. Maintenance

7-7 Parts replacement

NOTE Please contact RIKEN KEIKI to request sensor replacement. Calibration using a calibration gas isrequired after sensor replacement.

7-7-2 Replacement of periodic replacement parts
The product periodic replacement parts are as follows. The parts should be replaced at the recommended
replacement intervals.

<Recommended periodic replacement parts list>
Name
Sensor guard(for SD-3RI/GHS)
Sensor guard(for SD-3NC/GH/SP)
Sensor guard(for SD-3EC/ECS/ECB)
Silicone removal filter
Activated carbon filter

Recommended
check interval

Recommended
replacement interval

Quantity(per unit)

Remarks

3 - 8 years
6 months

1
1 year
1 yearProduct No.:4283 0030 20
Product No.:4283 0040 10

NOTE
 The above replacement intervals are guidelines only. Replacement intervals may vary depending on
actual operating conditions. These intervals do not constitute warranty periods. Replacement intervals
may vary depending on the results of regular maintenance.

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8. Storage, Relocation, and Disposal

8-1 Procedures for storage or when not in use for extended periods

8

Storage, Relocation, andDisposal
8-1 Procedures for storage or when not in use for extended
periods
The product must be stored in the following environment: In a location at normal temperatures and humidity and away from direct sunlight In a location free of gases, solvents, and vapor<Storage conditions (Sensor)>
Model

Storagelimit(years)－Temperature(°C)

Humidity*1(% RH)

Pressure(kPa)

Remarks

Minimum Maximum Minimum Maximum Minimum Maximum

SGF

0.5

-10

40

0

90

80

120

SHF

0.5

-10

40

0

90

80

120

NCF

0.5

-10

40

0

90

80

120

IRF

0.5

-10

40

0

90

80

120

ESF

0.5

-10

40

0

90

80

120

・ The sensor must be stored in the specified
packing case.
・ Store in a location away from direct
sunlight.
・ Store in an environment free of corrosive
gas, vibration, and dust.
・ Avoid condensation and moisture.
・ Store in an environment free of gases that
may act as a catalyst poison (e.g., silicone,chlorine, sulfur gases).
・ The sensor must be stored in the specified
packing case.
・ Store in a location away from direct
sunlight.
・ Store in an environment free of corrosive
gas, vibration, and dust.
・ Avoid condensation and moisture.
・ The sensor must be stored in the specified
packing case.
・ Store in a location away from direct
sunlight.
・ Store in an environment free of corrosive
gas, vibration, and dust.
・ Avoid condensation and moisture.
・ Store in an environment free of gases that
may act as a catalyst poison (e.g., silicone,chlorine, sulfur gases).

*1: Maximum humidity corresponds to an absolute humidity of 33 g/m3 (33.6 °C, 90 %RH) or less.

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8. Storage, Relocation, and Disposal

8-1 Procedures for storage or when not in use for extended periods<Storage conditions (Sensor-fitted SD-3)>
Storage

Model

limit
(years)－Temperature(°C)

Humidity*1(% RH)

Pressure(kPa)

Remarks

Minimum Maximum Minimum Maximum Minimum Maximum

SGF

0.5

-10

40

0

90

80

120

SHF

0.5

-10

40

0

90

80

120

NCF

0.5

-10

40

0

90

80

120

IRF

0.5

-10

40

0

90

80

120

0.5

-10

40

20

90

80

120

0.5

-10

40

30

80

80

120

ESF-A*2

ESF-X*3

ESF-B*4
ESF-C*5・ Store in a location away from direct
sunlight.
・ Store in an environment free ofcorrosive gas, vibration, and dust.
・ Avoid condensation and moisture.
・ Store in an environment free ofgases that may act as a catalyst
poison (e.g., silicone, chlorine, sulfur
gases).
・ Store in a location away from direct
sunlight.
・ Store in an environment free ofcorrosive gas, vibration, and dust.
・ Avoid condensation and moisture.
・ Store in a location away from direct
sunlight.
・ Store in an environment free ofcorrosive gas, vibration, and dust.
・ Avoid condensation and moisture.
・ Store in an environment free ofgases that may act as a catalyst
poison (e.g., silicone, chlorine, sulfur
gases).
・ Store in the dedicated sensor storage
container.*6
Open the dedicated container justbefore use, remove the sensor, andmount in the detector.

*1: Maximum humidity corresponds to an absolute humidity of 33 g/m3 (33.6 °C, 90 %RH).
*2: ESF-A refers to sensor model names starting with “ESF-A”.
*3: ESF-X refers to sensor model names starting with “ESF-X”.
*4: ESF-B refers to sensor model names starting with “ESF-B”.
*5: ESF-C refers to sensor model names starting with “ESF-C”.
*6: If not stored in the container, fluid leakage may occur under high humidity conditions of 90 %RH or more. Fluid
shortage may occur with the ESF-B under low humidity conditions.

CAUTION This product is very heavy and features various projections. Damage to this product and accompanying
parts may result if they are packaged in general packaging materials. When storing or returning the
product to RIKEN KEIKI for any reason, use the packaging in which the product was shipped. If theoriginal packaging is no longer available, wrap twice and place hard objects in the spaces within the
packaging to ensure that the product will not shift inside the packaging. Avoid packaging fragile items.

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8. Storage, Relocation, and Disposal

8-2 Procedures for relocation or reuse

8-2 Procedures for relocation or reuse
Before relocating and resuming use of the product, refer to ‘4-1 Installation precautions’ for information on
relocation locations.
For information on installation procedures, refer to ‘4. Installation’.

CAUTION Calibration must always be performed before resuming use of the product that has been relocated orpreviously stopped and stored. Contact RIKEN KEIKI for information on readjustment procedures,
including calibration.

8-3 Product disposal・・・・

Dispose of the product as industrial waste (incombustible) in accordance with local regulations.
Used sensor units must be returned to RIKEN KEIKI. Submit returns to RIKEN KEIKI.
Avoid direct contact with any fluid that may leak from electrochemical type sensors (ESF sensors). Place theunit in a plastic bag and make sure the fluid cannot leak out.
The product and ESF sensor contain button-type batteries. These batteries must be properly separated
before disposal. Contact your nearest sales office for advice.

<SD-3 main unit>
Button-type lithium battery specifications
Item name

Lithium battery

Nominal voltage

3.0 V

Nominal capacity

48 mAhRemoval method
Remove the main PCB unit indicated by the red box in the figure
to the right. Remove the PCB holder.
The battery is located on the underside of the main PCB (on therear of the 7-segment LCD).
The battery is covered by a plastic case. The plastic case isattached to the PCB. Remove the case using pliers or a flatheadscrewdriver.
Cut the terminals on both sides of the battery using nippers, thenremove.
Wrap the removed battery in tape to prevent short-circuiting before
disposal.

Battery

Main PCB

142 / 175

Plastic case

PCB holder

8. Storage, Relocation, and Disposal

8-3 Product disposal<ESF Sensor>
Button-type lithium battery specifications
Item nameNominal voltage:
Nominal capacity

Lithium manganese dioxide battery
3.0 V
140 mAh

Removal method

ESF Sensor

Remove the ESF sensor rear cover (white cover).
Remove the battery from the rear cover.
Wrap the removed battery in tape to prevent short-circuiting before
disposal.

Rear coverBattery

WARNING Never attempt to disassemble ESF sensors. They contain electrolyte. Blistering may result if theelectrolyte comes into contact with the skin. Contact with eyes may result in blindness. Discoloration orholes may result if contact with clothing occurs. If contact with electrolyte occurs, rinse the area
immediately with plenty of water.

NOTE The product contains a battery.
 Crossed-out recycle dustbin markThis pictogram is affixed to products containing batteries to which EU Battery
Directive 2006/66/EC applies.
Such batteries must be disposed of appropriately.
This pictogram means batteries must be separated from ordinary waste anddisposed of appropriately.

143 / 175

9. Troubleshooting

9-1 Product abnormalities

9

TroubleshootingThis troubleshooting section does not address causes of all problems that may occur with the product. It
provides brief explanations to assist in determining the causes of common problems.
If you encounter symptoms not addressed here or if problems persist even after taking corrective action, contact
RIKEN KEIKI.

9-1 Product abnormalities
Symptom/display

FAULT
lamp

The power cannot
be turned on.

―

Abnormaloperation

Cause

Action

The wires are incorrectly
connected.

Wire correctly.

The wires are detachedfrom the terminal plate.

Connect correctly.

Abnormalities or
instantaneousinterruptions in the power
supply circuit

Check to confirm that the rated voltage is
supplied.
Consider use of an uninterruptible power system,
power supply line filter, or insulated transformer,
and add such devices where appropriate.

Cable abnormality(Disconnection, cable notconnected, short circuit)

Check the wiring for the product and peripheraldevices.

Fuse blown

Replacement required. Contact RIKEN KEIKI.

Internal circuit abnormality

Replacement required. Contact RIKEN KEIKI.

Disturbances due tosudden noise, etc.

Turn off the power and restart. If similar
symptoms recur frequently, take appropriate
measures to address the noise source.
If the problem persists even with noise prevention
measures, contact RIKEN KEIKI.

The sensor is notconnected or connected
improperly.

Turn off the power and check the sensor
connection.

A sensor fault has
occurred.

Replace with a new sensor.

Effects of sudden surge
noise

Turn off the power and restart. If similar
symptoms recur frequently, take appropriate
measures to address the noise source.
If the problem persists even with noise prevention
measures, contact RIKEN KEIKI.

―

Sensorabnormality
(E-1)

(lit)

The main unit (SD-3/
Connect internal wiring of the main unit (SD-3/
SD-3SC) or remote sensor SD-3SC) or remote sensor head (GD-3) correctly.
head (GD-3) internal wiring
is connected incorrectly.

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9. Troubleshooting

Symptom/display

9-2 Reading abnormalities

FAULT
lamp

Sensorabnormality
(E-1)
(lit)

Systemabnormality
(E-9)
(lit)
GD-3 abnormality(E-1A)

(lit)

Cause

ActionCable abnormality
between the main unit
(SD-3SC) and remotesensor head (GD-3)

Check the cable between the main unit (SD-3SC)
and remote sensor head (GD-3).

A main unit (SD-3/
SD-3SC) or remote sensor
head (GD-3) fuse has
blown.

Replacement required. Contact RIKEN KEIKI.

Main unit (SD-3/SD-3SC)or remote sensor head
(GD-3) internal circuit
abnormality

Replacement required. Contact RIKEN KEIKI.

4 - 20 mA output
disconnection

Turn off the power and check the 4 - 20 mA
output connection.

Internal ROM, RAM, or
EEPROM fault

Turn off the power and restart. If the problem
persists, replacement is necessary. Contact
RIKEN KEIKI.

The sensor is notconnected or connected
improperly.

Turn off the power and check the sensor
connection.

A sensor fault has
occurred.

Replace with a new sensor.

Effects of sudden surge
noise

Turn off the power and restart. If similar
symptoms recur frequently, take appropriate
measures to address the noise source.
If the problem persists even with noise prevention
measures, contact RIKEN KEIKI.

9-2 Reading abnormalities
Symptom/display
・ The reading
rises (or drops)
and remains
unchanged.
・ A gas alarm istriggereddespite theabsence of agas leak or any
otherabnormalities atthe detection
area.
・ Response is
slow.

FAULT
lamp

Cause

ActionThe sensor zero or
span has altered(drifted).

Perform zero calibration or span adjustment.

Presence of interference
gases

Check for the presence of interference gases
such as solvents and take appropriate action.

Slow leakage

Trace amounts of detection target gas may beleaking. Leaving this unresolved may lead tohazardous conditions. Take the same action
as for gas alarms.

Environmental
fluctuations

Perform zero calibration or span adjustment.

Effects of noise

Turn off the power and restart. If similar
symptoms recur frequently, take appropriate
measures to address the noise source.

―

If the problem persists even with noise
prevention measures, contact RIKEN KEIKI.

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9. Troubleshooting

Symptom/display

9-2 Reading abnormalities

FAULT
lamp

Systemabnormality
(E-9)

Cause

ActionSudden environmental
changes

Alarm indications may be issued by the productdue to sudden environmental fluctuations (e.g.,temperature).
The product cannot be used in locations where
sudden environmental changes occur frequently.
The user should take appropriate measures.

The sensor sensitivity
has degraded.

Replace with a new sensor.

The calibration gas
concentration isinappropriate.

Prepare the correct calibration gas.

The sensor sensitivity
has degraded.

Replace with a new sensor.

Clock abnormality

Set the date and time.
Correction may not function correctly if the EC
sensitivity correction function is enabled.
If similar symptoms recur frequently, the internal
clock may be defective. Replace with a newinternal clock.
Contact RIKEN KEIKI.

Ambient temperatures atthe location where theproduct is installed areoutside the operating
temperature range.

The product operating temperature range varies
with the specific detection principle. The productcannot be used outside the operating
temperature range.
The user should take appropriate measures.

The sensor isapproaching the end ofits service life.

We recommend sensor replacement.
Contact RIKEN KEIKI.

―

Outside operating
temperature
range(E-27)―

Sensor life
expiration
warning(E-8)―

Sensor warning
(E-1)

―

Contact RIKEN KEIKI.

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10. Product Specifications

10-1 SD-3 specifications

10

Product Specifications
10-1 SD-3 specifications
10-1-1 SD-3 (model without EC barrier)ModelSpecifications
Display
Sensor
Detection principle
Detection target gas
Detection range
Sampling method
Set flow rate
Power supply
indication
External output
Alarm setpoints
Alarm accuracy
Alarm delay time
Repeatability (foridentical conditions)Indication accuracy(for identical conditions)
Gas alarm typeGas alarm
indication
Gas alarm reset
operation
Fault alarm/self
diagnosis
Fault alarmindication
Fault alarm reset
operation

Contact operation

Warnings
Warning display
Warning operation

SD-3
Standard

SD-3 (contact model)
Contact
7-segment LED (5 digits)
F sensor (RIKEN KEIKI)
Infrared/electrochemical/new ceramic (catalytic)/semiconductor/hot-wiresemiconductor
Depends on sensor specifications.
Depends on sensor specifications.
Diffusion type/suction type (introduced via external unit)
0.4 - 1.5 L/min
Power lamp lit (green)
Gas concentration signal (4 - 20 mA DC + HART output)
Depends on sensor specifications.
Depends on sensor specifications.
Depends on sensor specifications.
Depends on sensor specifications.
Depends on sensor specifications.
Two-step alarm (H-HH, H-L, or L-LL)
Alarm lamp lit (red)Auto reset or self-latching
System abnormality (E-9)/sensor abnormality (E-1)
Fault lamp lit (yellow)/error code display
System abnormality: Self-latching
Sensor abnormality: Auto reset (self-latching if sensor is disconnected)
SPDT (× 3):
2 alarms, 1 fault output―
250 V AC, 2 A; 30 V DC, 1 A (resistanceload)
Minimum load 5 V DC, 0.1 A
Sensor life assessment/clock abnormality diagnosis/communication diagnosis/
sensor warning
Blinking display alternating between gas concentration and error code
Same as normal operation
147 / 175

10. Product Specifications

Model
Functions
Transmission
method (4 - 20 mA)
Transmission
specifications(4 - 20 mA)
Transmission cable(4 - 20 mA)
Transmission
distance(4 - 20 mA)
Power source

Power supply cable
Power consumption
Cable connectors
Operation method
Operatingtemperature range
Operating humidity
range
Housing material
Protection level
Installation type
Explosion-proof
construction
Explosion-proof
class
External
dimensions
Weight10-1 SD-3 specifications

SD-3
SD-3 (contact model)
Alarm delay/suppression/HART communication
3-wire analog transmission (common power supply <power supply, signal,common>) or
2-wire analog transmission (current source)
4 mA - 20 mA DC (non-insulated linear output)
Maximum load resistance 600 Ω (with derating depending on power supply voltage)
Resolution: max. 250 divisions (depending on specifications)Shielded cable 1.25 sq (1.308 mm2/AWG16) or
2.0 sq (2.08 mm2/AWG14) (same as power supply cable)*To ensure explosion protection, use a cable designed for use in temperatures atleast 5 °C above the maximum anticipated ambient temperature.
For 1.25 sq (1.308 mm2/AWG16): Not exceeding 1.25 km
For 2.0 sq (2.08 mm2/AWG14): Not exceeding 2 km (with derating depending on
supply voltage)
24 V DC (18 V - 30 V DC)*Use a power supply capable of minimum temporary output of 2.5 A to ensure thatfuses blow normally in the event of a product abnormality.
Shielded cable 1.25 sq (1.308 mm2/AWG16) or
2.0 sq (2.08 mm2/AWG14) (same as transmission cable)*To ensure explosion protection, use a cable designed for use in temperatures atleast 5 °C above the maximum anticipated ambient temperature.
Refer to ‘10-1-3 Electrical ratings (SD-3)’.
M25 × 1.5
Dedicated magnet control key−40 °C - +70 °C (no sudden changes)
In accordance with sensor specifications if restrictions apply due to sensor
specifications
0 %RH - 95 %RH (no condensation)
In accordance with sensor specifications if restrictions apply due to sensor
specifications
Stainless steel (SCS14)
IP66/67 equivalent
Wall mounting (standard)/2B pole mounting (optional)
Flame-proof construction
Varies depending on model.
Refer to <Explosion-proof performance data> in ‘2-4 Safety information’.
Diffusion type: Approx. 171 mm (W) × 277 mm (H) × 127 mm (D) (excluding projections)Suction type: Approx. 171 mm (W) × 289 mm (H) × 127 mm (D) (excluding projections)Diffusion type: approx. 6.7 kg/Suction type: approx. 7.0 kg*When used with the contacts closed, the contacts may seize due to vibration. Keep this precaution in mind.

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10. Product Specifications

10-1 SD-3 specifications<Dimensional drawings (SD-3 (model without EC barrier))><Diffusion type>74<Suction type>74

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10. Product Specifications

10-1 SD-3 specifications

10-1-2 SD-3 (model with EC barrier)ModelSpecifications
Display
Sensor
Detection principle
Detection target
gas
Detection range
Sampling method
Set flow rate
Power supply
indication
External output
Alarm setpoints
Alarm accuracy
Alarm delay time
Repeatability (foridentical conditions)Indication accuracy(for identical conditions)
Gas alarm typeGas alarm
indication
Gas alarm reset
operation
Fault alarm/self
diagnosis
Fault alarmindication
Fault alarm reset
operation
Contact operation

Warnings
Warning display
Warning operation
Functions
Transmission
method (4 - 20 mA)
Transmission
specifications(4 - 20 mA)
Transmission cable(4 - 20 mA)
Transmission
distance(4 - 20 mA)

SD-3
Standard

SD-3 (contact model)
Contact
7-segment LED (5 digits)
F sensor (RIKEN KEIKI)
Electrochemical type

Depends on sensor specifications.
Depends on sensor specifications.
Diffusion type/suction type (introduced via external unit)
0.4 - 1.5 L/min
Power lamp lit (green)
Gas concentration signal (4 - 20 mA DC + HART output)
Depends on sensor specifications.
Depends on sensor specifications.
Depends on sensor specifications.
Depends on sensor specifications.
Depends on sensor specifications.
Two-step alarm (H-HH, H-L, or L-LL)
Alarm lamp lit (red)Auto reset or self-latching
System abnormality (E-9)/sensor abnormality (E-1)
Fault lamp lit (yellow)/error code display
System abnormality: Self-latching
Sensor abnormality: Auto reset (self-latching if sensor is disconnected)
SPDT (× 3):
2 alarms, 1 fault output―
250 V AC, 2A; 30 V DC, 1 A (resistanceload)
Minimum load 5 V DC, 0.1 A
Sensor life assessment/clock abnormality diagnosis/communication diagnosis/
sensor warning
Blinking display alternating between gas concentration and error code
Same as normal operation
Alarm delay/suppression/HART communication
3-wire analog transmission (common power supply <power supply, signal,common>) or
2-wire analog transmission (current source)
4 mA - 20 mA DC (non-insulated linear output)
Maximum load resistance 600 Ω (with derating depending on power supply voltage)
Resolution: max. 250 divisions (depending on specifications)Shielded cable 1.25 sq (1.308 mm2/AWG16) or
2.0 sq (2.08 mm2/AWG14) (same as power supply cable)*To ensure explosion protection, use a cable designed for use in temperatures atleast 5 °C above the maximum anticipated ambient temperature.
For 1.25 sq (1.308 mm2/AWG16): Not exceeding 1.25 km
For 2.0 sq (2.08 mm2/AWG14): Not exceeding 2 km (with derating depending on
supply voltage)

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10. Product Specifications

Model
Power source

Power supply cable
Power consumption
Cable connectors
Operation method
Operatingtemperature range
Operating humidity
range
Housing material
Protection level
Installation type
Explosion-proof
construction
Explosion-proof
class
External
dimensions
Weight10-1 SD-3 specifications

SD-3

SD-3 (contact model)
24 V DC (18 V - 30 V DC)*Use a power supply capable of minimum temporary output of 2.5 A to ensure thatfuses blow normally in the event of a product abnormality.
Shielded cable 1.25 sq (1.308 mm2/AWG16) or
2.0 sq (2.08 mm2/AWG14) (same as transmission cable)*To ensure explosion protection, use a cable designed for use in temperatures atleast 5 °C above the maximum anticipated ambient temperature.
Refer to ‘10-1-3 Electrical ratings (SD-3)’.
M25 × 1.5
Dedicated magnet control key−40 °C - +70 °C (no sudden changes)
In accordance with sensor specifications if restrictions apply due to sensor
specifications
0 %RH - 95 %RH (no condensation)
In accordance with sensor specifications if restrictions apply due to sensor
specifications
Stainless steel (SCS14)
IP66/67 equivalent
Wall mounting (standard)/2B pole mounting (optional)
Flame-proof construction + intrinsically safe explosion-proof construction
Varies depending on model.
Refer to <Explosion-proof performance data> in ‘2-4 Safety information’.
Diffusion type: Approx. 171 mm (W) × 322 mm (H) × 127 mm (D) (excluding projections)Suction type: Approx. 171 mm (W) × 334 mm (H) × 127 mm (D) (excluding projections)Diffusion type: approx. 7.3 kg/Suction type: approx. 7.6 kg*When used with the contacts closed, the contacts may seize due to vibration. Keep this precaution in mind.

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10. Product Specifications

10-1 SD-3 specifications<Dimensional drawings (SD-3 (model with EC barrier))><Diffusion type>74<Suction type>74

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10. Product Specifications

10-1 SD-3 specifications

10-1-3 Electrical ratings (SD-3)
Model
SD-3RIPower supply
24 V DC (18 V - 30 V DC)

Power consumption
Max. 3.8 W

SD-3GH

24 V DC (18 V - 30 V DC)

Max. 4.5 W

SD-3GHS

24 V DC (18 V - 30 V DC)

Max. 4.5 W

SD-3NC

24 V DC (18 V - 30 V DC)

Max. 4.5 W

SD-3SP

24 V DC (18 V - 30 V DC)

Max. 3.5 W

SD-3EC

24 V DC (18 V - 30 V DC)

Max. 2.8 W

SD-3ECS

24 V DC (18 V - 30 V DC)

Max. 2.8 W

SD-3ECB

24 V DC (18 V - 30 V DC)

Max. 3.1 W

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10. Product Specifications

10-2 SD-3SC + GD-3 specifications

10-2 SD-3SC + GD-3 specifications
10-2-1 SD-3SC + GD-3 (model without EC barrier)ModelSpecifications
Display
Sensor
Detection principle
Detection target gas
Detection range
Sampling method
Power supply
indication
External output
Alarm setpoints
Alarm accuracy
Alarm delay time
Repeatability(for identicalconditions)Indication accuracy(for identicalconditions)
Gas alarm typeGas alarm indication
Gas alarm reset
operation
Fault alarm/self
diagnosis
Fault alarm indication
Fault alarm reset
operation
Contact operation

Warnings
Warning display
Warning operation
Functions
Transmission
method (4 - 20 mA)
Transmission
specifications(4 - 20 mA)

SD-3SC (contact model)+ GD-3Standard
Contact
7-segment LED (5 digits)
F sensor (RIKEN KEIKI)
Infrared/electrochemical/new ceramic (catalytic)/semiconductor/hot-wiresemiconductor
Depends on sensor specifications.
Depends on sensor specifications.
Diffusion type
SD-3SC + GD-3

Power lamp lit (green)
Gas concentration signal (4 - 20 mA DC + HART output)
Depends on sensor specifications.
Depends on sensor specifications.
Depends on sensor specifications.
Depends on sensor specifications.

Depends on sensor specifications.
Two-step alarm (H-HH, H-L, or L-LL)
Alarm lamp lit (red)Auto reset or self-latching
System abnormality (E-9)/sensor abnormality (E-1)
Fault lamp lit (yellow)/error code display
System abnormality: Self-latching
Sensor abnormality: Auto reset (self-latching if sensor is disconnected)
SPDT (× 3):
2 alarms, 1 fault output―
250 V AC, 2A; 30 V DC, 1 A (resistance load)
Minimum load 5 V DC, 0.1 A
Sensor life assessment/clock abnormality diagnosis/communication diagnosis/
sensor warning
Blinking display alternating between gas concentration and error code
Same as normal operation
Alarm delay/suppression/HART communication
3-wire analog transmission (common power supply <power supply, signal,common>) or
2-wire analog transmission (current source)
4 mA - 20 mA DC (non-insulated linear output)
Maximum load resistance 600 Ω (with derating depending on power supply voltage)
Resolution: max. 250 divisions (depending on specifications)

154 / 175

10. Product Specifications

Model
Transmission cable(4 - 20 mA)
Transmission
distance (4 - 20 mA)
Transmission cable(between GD-3 units)
Transmission
distance (between
GD-3 units)10-2 SD-3SC + GD-3 specifications

SD-3SC (contact model)+ GD-3
2
Shielded cable 1.25 sq (1.308 mm /AWG16) or
2.0 sq (2.08 mm2/AWG14) (same as power supply cable)*To ensure explosion protection, use a cable designed for use in temperatures atleast 5 °C above the maximum anticipated ambient temperature.
SD-3SC + GD-3

For 1.25 sq (1.308 mm2/AWG16): Not exceeding 1.25 km
For 2.0 sq (2.08 mm2/AWG14): Not exceeding 2 km (with derating depending on
supply voltage)
Shielded twisted pair cable 1.25 sq (1.308 mm2/AWG16)*To ensure explosion protection, use a cable designed for use in temperatures atleast 5 °C above the maximum anticipated ambient temperature.
20 m (maximum)

Power source

24 V DC (18 V - 30 V DC)*Use a power supply capable of minimum temporary output of 2.5 A to ensure thatfuses blow normally in the event of a product abnormality.

Power supply cable

Shielded cable 1.25 sq (1.308 mm2/AWG16) or
2.0 sq (2.08 mm2/AWG14) (same as transmission cable)*To ensure explosion protection, use a cable designed for use in temperatures atleast 5 °C above the maximum anticipated ambient temperature.

Power consumption
Cable connectors
Operation method
Operatingtemperature range
Operating humidity
range
Housing material
Protection level
Installation type
Explosion-proof
construction
Explosion-proof class
External dimensions(SD-3SC)
Weight (SD-3SC)
External dimensions(GD-3)
Weight (GD-3)

Refer to ‘10-2-3 Electrical ratings (SD-3SC + GD-3)’.
M25 × 1.5
Dedicated magnet control key−40 °C - +70 °C (no sudden changes)
In accordance with sensor specifications if restrictions apply due to sensor
specifications
0 %RH - 95 %RH (no condensation)
In accordance with sensor specifications if restrictions apply due to sensor
specifications
Stainless steel (SCS14)
IP66/67 equivalent
Wall mounting (standard)/2B pole mounting (optional)
Flame-proof construction
Varies depending on model.
Refer to <Explosion-proof performance data> in ‘2-4 Safety information’.
Diffusion type: Approx. 171 mm (W) × 193 mm (H) × 127 mm (D) (excluding projections)
Approx. 6.0 kg
Approx. 125 mm (W) × 195 mm (H) × 88 mm (D) (excluding projections)
Approx. 3.0 kg*When used with the contacts closed, the contacts may seize due to vibration. Keep this precaution in mind.

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10. Product Specifications

10-2 SD-3SC + GD-3 specifications<Dimensional drawings (SD-3SC + GD-3 (model without EC barrier))><Main unit (SD-3SC)>74<Remote sensor unit (GD-3 (model without EC barrier))>

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10. Product Specifications

10-2 SD-3SC + GD-3 specifications

10-2-2 SD-3SC + GD-3 (model with EC barrier)ModelSpecifications
Display
Sensor
Detection principle
Detection target gas
Detection range
Sampling method
Power supply
indication
External output
Alarm setpoints
Alarm accuracy
Alarm delay time
Repeatability(for identicalconditions)Indication accuracy(for identicalconditions)
Gas alarm typeGas alarm indication
Gas alarm reset
operation
Fault alarm/self
diagnosis
Fault alarm indication
Fault alarm reset
operation

Contact operation

Warnings
Warning display
Warning operation
Functions
Transmission
method (4 - 20 mA)
Transmission
specifications(4 - 20 mA)
Transmission cable(4 - 20 mA)

SD-3SC (contact model)+ GD-3Standard
Contact
7-segment LED (5 digits)
F sensor (RIKEN KEIKI)
Electrochemical type
Depends on sensor specifications.
Depends on sensor specifications.
Diffusion type

SD-3SC + GD-3

Power lamp lit (green)
Gas concentration signal (4 - 20 mA DC + HART output)
Depends on sensor specifications.
Depends on sensor specifications.
Depends on sensor specifications.
Depends on sensor specifications.

Depends on sensor specifications.
Two-step alarm (H-HH, H-L, or L-LL)
Power lamp lit (red)Auto reset or self-latching
System abnormality (E-9)/sensor abnormality (E-1)
Fault lamp lit (yellow)/error code display
System abnormality: Self-latching
Sensor abnormality: Auto reset (self-latching if sensor is disconnected)
SPDT (× 3):
2 alarms, 1 fault output―
250 V AC, 2A; 30 V DC, 1 A (resistanceload)
Minimum load 5 V DC, 0.1 A
Sensor life assessment/clock abnormality diagnosis/communication diagnosis/
sensor warning
Blinking display alternating between gas concentration and error code
Same as normal operation
Alarm delay/suppression/HART communication
3-wire analog transmission (common power supply <power supply, signal,common>) or
2-wire analog transmission (current source)
4 mA - 20 mA DC (non-insulated linear output)
Maximum load resistance 600 Ω (with derating depending on power supply
voltage)
Resolution: max. 250 divisions (depending on specifications)Shielded cable 1.25 sq (1.308 mm2/AWG16) or
2.0 sq (2.08 mm2/AWG14) (same as power supply cable)*To ensure explosion protection, use a cable designed for use in temperatures atleast 5 °C above the maximum anticipated ambient temperature.
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10. Product Specifications

Model
Transmission
distance (4 - 20 mA)
Transmission cable(between GD-3 units)
Transmission
distance (between
GD-3 units)
Power source

Power supply cable
Power consumption
Cable connectors
Operation method
Operatingtemperature range
Operating humidity
range
Housing material
Protection level
Installation type
Explosion-proof
construction

10-2 SD-3SC + GD-3 specifications

SD-3SC (contact model)+ GD-32
For 1.25 sq (1.308 mm /AWG16): Not exceeding 1.25 km
For 2.0 sq (2.08 mm2/AWG14): Not exceeding 2 km (with derating depending on
supply voltage)
Shielded twisted pair cable 1.25 sq (1.308 mm2/AWG16)*To ensure explosion protection, use a cable designed for use in temperatures atleast 5 °C above the maximum anticipated ambient temperature.
SD-3SC + GD-3

20 m (maximum)
24 V DC (18 V - 30 V DC)*Use a power supply capable of minimum temporary output of 2.5 A to ensure thatfuses blow normally in the event of a product abnormality.
Shielded cable 1.25 sq (1.308 mm2/AWG16) or
2.0 sq (2.08 mm2/AWG14) (same as transmission cable)*To ensure explosion protection, use a cable designed for use in temperatures atleast 5 °C above the maximum anticipated ambient temperature.
Refer to ‘10-2-3 Electrical ratings (SD-3SC + GD-3)’.
M25 × 1.5
Dedicated magnet control key−40 °C - +70 °C (no sudden changes)
In accordance with sensor specifications if restrictions apply due to sensor
specifications
0 %RH - 95 %RH (no condensation)
In accordance with sensor specifications if restrictions apply due to sensor
specifications
Stainless steel (SCS14)
IP66/67 equivalent
Wall mounting (standard)/2B pole mounting (optional)
Flame-proof construction + intrinsically safe explosion-proof construction

Explosion-proof class

Varies depending on model.
Refer to <Explosion-proof performance data> in ‘2-4 Safety information’.

External dimensions(SD-3SC)

Diffusion type: Approx. 171 mm (W) × 193 mm (H) × 127 mm (D)(excluding projections)

Weight (SD-3SC)
External dimensions(GD-3)
Weight (GD-3)

Approx. 6.0 kg
Approx. 125 mm (W) × 240 mm (H) × 88 mm (D)(excluding projections)
Approx. 4.0 kg*When used with the contacts closed, the contacts may seize due to vibration. Keep this precaution in mind.

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10. Product Specifications

10-2 SD-3SC + GD-3 specifications<Dimensional drawings (SD-3SC + GD-3 (model with EC barrier))><Main unit (SD-3SC)>74<Remote sensor unit (GD-3 (model without EC barrier))>

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10. Product Specifications

10-2 SD-3SC + GD-3 specifications

10-2-3 Electrical ratings (SD-3SC + GD-3)
Model

Power supply

Power consumption

SD-3SC

24 V DC (18 V - 30 V DC)

Max. 5 W

GD-3RI

24 V DC (18 V - 30 V DC)

Max. 1.2 W

GD-3GH

24 V DC (18 V - 30 V DC)

Max. 2 W

GD-3GHS

24 V DC (18 V - 30 V DC)

Max. 2 W

GD-3NC

24 V DC (18 V - 30 V DC)

Max. 2 W

GD-3SP

24 V DC (18 V - 30 V DC)

Max. 1 W

GD-3EC

24 V DC (18 V - 30 V DC)

Max. 1 W

GD-3ECS

24 V DC (18 V - 30 V DC)

Max. 1 W

GD-3ECB

24 V DC (18 V - 30 V DC)

Max. 1 W

160 / 175

10. Product Specifications

10-3 Detection target gases for individual detection principles

10-3 Detection target gases for individual detection principles
10-3-1 Non-dispersive infrared absorption type (Infrared type)
Sensormodel

Gas nameGassymbol

F.S.

First

Second1 digitAlarm
setpointAlarm
setpoint

Calibration
OperatingOperatinggas
temperature range humidity range(alternative(no sudden changes) (no condensation)gas)

IRF-1301*

MethaneCH4

100 %LEL

0.5 %LEL

25 %LEL

50 %LELCH4

IRF-1303*

Isobutane

i-C4H10

100 %LEL

0.5 %LEL

25 %LEL

50 %LEL

i-C4H10

IRF-1317*

Propane

C3H8

100 %LEL

0.5 %LEL

25 %LEL

50 %LEL

IRF-1435

Carbon dioxide

CO22,000 ppm

1 ppm

1,000 ppm-

CO2

IRF-1436

Carbon dioxide

CO25,000 ppm

10 ppm

1,000 ppm-

CO2

IRF-1433

Carbon dioxideCO210,000 ppm

10 ppm

1,000 ppm-

CO2

IRF-1437

Carbon dioxide

CO2

2 vol%

0.005
vol%

1 vol%-CO2

IRF-1438

Carbon dioxide

CO2

5 vol%

0.010
vol%

1 vol%-CO2

IRF-1439

Carbon dioxide

CO2

10 vol%0.01 vol%

1 vol%-CO2

IRF-1334*

MethaneCH4

100 vol%

0.5 vol%

25 vol%50 vol%CH4

IRF-1316*

Ethylene

C2H4

100 %LEL

0.5 %LEL

25 %LEL

50 %LEL

IRF-1340*

Isobutylene

i-C4H8

100 %LEL

0.5 %LEL

25 %LEL

50 %LEL

IRF-1308*

N-hexanen-C6H14

100 %LEL

0.5 %LEL

25 %LEL

50 %LEL

IRF-1332*

Butadiene

C4H6

100 %LEL

0.5 %LEL

25 %LEL

50 %LELYears ofwarranty

C3H8(i-C4H10)−40 - 70 °C

95 %RH or less

3 years

C2H4(CH4)
i-C4H8(i-C4H10)
n-C6H14(i-C4H10)
C4H6
(CH4)

*Interference occurs due to other hydrocarbon gases.

NOTE
 Install in a location with stable conditions within the specified operating temperature range and free of
sudden fluctuations.
 When calibrating, allow the product to warm up for at least 10 minutes before performing zero calibrationand span adjustment.
 Ensure identical temperatures, humidity, and pressure in the calibration and measurement environments.
(Readings may fluctuate due to temperature, humidity, and pressure characteristics. In some cases,
readings may exceed the zero suppression value due to sensor characteristics.)
 For low gas sensitivity ethylene and butadiene, we recommend using with the alarm settings at 25 %LEL
or greater.
 If the composition of the base gas differs greatly for calibration and measurement—for example, if an air
base is used for calibration but a CO2 base is used for measurement—reading may differ due to infraredadsorption characteristics, even if the concentration of the target gas is the same.
 Perform maintenance if a warning appears while the life assessment or self-diagnostic function is active.
 Use the IRF sensor adapter when calibrating. Calibration accuracy may be impaired without the IRF
sensor adapter.
 The warranty period for IRF sensors is three years, regardless of detection target gas.

161 / 175

10. Product Specifications

10-3 Detection target gases for individual detection principles

10-3-2 New ceramic type (catalytic type)
Sensormodel

Gas nameGassymbolF.S.

1 digitFirst

Second

Alarm

Alarm

setpoint

setpoint

Calibrationgas

NCF-6318

MethaneCH4

100 %LEL 0.5 %LEL

25 %LEL

50 %LEL

CH4*2

NCF-6319

VCM

VCM

100 %LEL 0.5 %LEL

25 %LEL

50 %LEL

i-C4H10

NCF-6320

HydrogenH2

100 %LEL 0.5 %LEL

25 %LEL

50 %LELH2*3

OperatingOperatingtemperature range humidity range(no sudden changes) (no condensation)−40 - 70 °C

0 - 95 %RH*1

Years ofwarranty

3 years*1: Absolute humidity not exceeding 46 g/m3 (equivalent to 37 °C, 95 %RH)
*2: Use the NCF-6318 if methane calibration is required or when the detection target gas is methane, propane, or ethane. The detection target gas
overlaps for the NCF-6318 and NCF-6319. Use the NCF-6319 in cases other than the above.
*3: Use the NCF-6320 if hydrogen selectivity is required.

NOTE
 Install in a stable location within the specified operating temperature range and free of sudden
temperature fluctuations.
 Sensor characteristics may degrade significantly in the presence of silicone gases (organic silicone
gases), the various types of halogen gases, sulfide gases, or acidic gases.
 A silicone removal filter and activated carbon filter are available as options.
 For models with a F.S. of 5,000 ppm or less, allow the product to warm up for at least 120 minutes inclean air before performing zero calibration and span adjustment.
 For models with a F.S. of 5,000 ppm or less, the effects of ambient humidity and temperature fluctuations
will become more significant, and the zero point may drift. If so, turn the zero follower function ON.
However, we recommend using a sensor with a different detection principle. The zero follower function is
not available if gases are always present.
 Readings may be affected by combustible gases other than the detection target gas.
 When oxygen concentrations fall, the readings may also fall.
 Some interference may occur in the presence of highly thermally conductive gases such as CO2, Ar, andHe in high concentrations as base gases.
 When low vapor pressure gases are detected by aspiration, the gas may condense when aspirated fromwarmer areas and detected in cooler areas, or blockages may occur in sintered alloy. Keep vapor
pressure in mind when using the product.
 Perform maintenance if a warning appears while the life assessment or self-diagnostic function is active.
 Use the combustible gas sensor adapter when calibrating. Calibration accuracy may be impaired without
the combustible gas sensor adapter.
 Indication accuracy may degrade in situations in which temperatures fluctuate significantly (±40 °C or
greater) above or below the ambient temperature in which zero calibration or span adjustment was
performed. If this occurs, repeat zero calibration or span adjustment.
 There may be fluctuations in readings if the product receives strong shocks from outside or is subjected
to vibrations. If this occurs, perform zero calibration and span adjustment.
 The zero point may fluctuate if the sensor is in continuous contact with high-concentration gas of
100 %LEL or more for extended periods. If this occurs, perform zero calibration and span adjustment.
 The sensor may be hot during replacement. Be careful to avoid burns when replacing the sensor. If thesensor is hot, turn off the power and wait for it to cool.
 There is a Teflon film on the top of the sensors. The performance of the sensor may be affected if thisTeflon film is damaged. Avoid applying excessive pressure or sharp objects to the Teflon film.
 The warranty period for NCF sensors is three years, regardless of detection target gas.

162 / 175

10. Product Specifications

10-3 Detection target gases for individual detection principles

10-3-3 Semiconductor type
Sensormodel

Gas nameGassymbolF.S.

1 digit

First
alarm
setpoint

OperatingOperating
SecondCalibration
alarm
temperature range humidity range
gas
setpoint

SGF-8562
SGF-8563

Carbon disulfide
Ethylene oxide

CS2
EO

200 ppm
100 ppm

1 ppm
1 ppm

50 ppm25 ppm100 ppm
50 ppmCS2
EO

SGF-8562

Hydrogen sulfide

H2S

100 ppm

1 ppm

25 ppm50 ppmH2S(no sudden changes)(no condensation)-20 - 65 °C

20 - 95 %RH*

Warranty
period3 years*Absolute humidity not exceeding 46 g/m3 (equivalent to 37 °C, 95 %RH)

NOTE
 Sensor characteristics may degrade significantly in the presence of silicone gases (organic silicone
gases), the various types of halogen gases, sulfide gases, or acidic gases.
 A silicone removal filter and activated carbon filter are available as options.
 Select the calibration gas after accounting for typical humidity in the operating environment.
 When calibrating, allow a warmup time depending on the unpowered period in clean air before
proceeding with the zero calibration and span adjustment. Refer to ‘<Warmup times for semiconductor
type sensors>’ below for warmup times.
 Readings may be affected by combustible gases other than the detection target gas.
 Readings may fluctuate in the presence of fluctuations (e.g., temperature and humidity) in the installation
location.
 When oxygen concentrations fall, the readings may also fall.
 Some interference may occur in the presence of highly thermally conductive gases such as CO2, Ar, andHe in high concentrations as base gases.
 When low vapor pressure gases are detected by aspiration, the gas may condense when aspirated fromwarmer areas and detected in cooler areas, or blockages may occur in sintered alloy. Keep vapor
pressure in mind when using the product.
 Perform maintenance if a warning appears while the life assessment or self-diagnostic function is active.
 Use the combustible gas sensor adapter when calibrating. Calibration accuracy may be impaired without
the combustible gas sensor adapter.
 Indication accuracy may degrade in situations in which temperatures fluctuate significantly (±20 °C or
greater) above or below the ambient temperature in which zero calibration or span adjustment was
performed. If this occurs, repeat zero calibration or span adjustment.
 There may be fluctuations in readings if the product receives strong shocks from outside or is subjected
to vibrations. If this occurs, perform zero calibration and span adjustment.
 The zero point may fluctuate if the sensor comes into contact with high-concentration gas continuously
for extended periods. If this occurs, perform zero calibration and span adjustment.
 Readings may fall in environments where gas is continuously present.
 The sensor may be hot during replacement. Be careful to avoid burns when replacing the sensor. If thesensor is hot, turn off the power and wait for it to cool.
 There is a Teflon film on the top of the sensors. There may be an impact on the performance of thesensor if this Teflon film is damaged. Avoid applying excessive pressure or sharp objects to the Teflon
film.
 Calibration is not possible if the reading during calibration does not exceed the zero suppression value.
If the reading is below the zero suppression value when the desired calibration gas is introduced forcalibration, first calibrate using a gas that gives a reading higher than the zero suppression value, thencalibrate using the desired calibration gas.
 Depending on the conditions and length of time for which the power was turned off, the reading maychange when the power is turned on, even after the warmup time (three minutes) has elapsed. If thisoccurs, wait until the reading returns to zero.
 The warranty period for SGF sensors is three years, regardless of detection target gas.

163 / 175

10. Product Specifications

10-3 Detection target gases for individual detection principles<Semiconductor type sensor warmup times>
Unpowered period
Within 10 minutes
Within 1 hourWithin 24 hours
Within 72 hours
Within 10 days
Less than 1 month
1 month to less than 3 months
3 months or more

Warmup time
30 minutes or more
2 hours or more
4 hours or more
24 hours or more
2 days or more
7 days or more
14 days or more
1 month or more

164 / 175

10. Product Specifications

10-3 Detection target gases for individual detection principles

10-3-4 Hot-wire semiconductor type
Sensormodel

Gas nameGassymbolF.S.

1 digit

First
alarm
setpoint

Secondalarm
setpoint

Calibration
gas

OperatingOperatingtemperature range

humidity range(no sudden changes)(no condensation)

SHF-8601

MethaneCH45,000 ppm

25 ppm

2,000 ppm 4,000 ppm

CH4-30 - 70 °C

SHF-8601

CarbonmonoxideCO

1,000 ppm

10 ppm

250 ppm

CO

0 - 70 °C

SHF-8602

Isobutane

i-C4H102,000 ppm

10 ppm

500 ppm 1,000 ppm

i-C4H10-30 - 70 °C

SHF-8603

HydrogenH2

2,000 ppm

10 ppm

500 ppm 1,000 ppm

H2-30 - 70 °C

500 ppm

20 - 95 %RH*

Warranty
period3 years3*Absolute humidity not exceeding 46 g/m (equivalent to 37 °C, 95 %RH)

NOTE
 Sensor characteristics may degrade significantly in the presence of silicone gases (organic silicone
gases), the various types of halogen gases, sulfide gases, or acidic gases.
 A silicone removal filter and activated carbon filter are available as options.
 Select the calibration gas after accounting for typical humidity in the operating environment.
 When calibrating, allow a warmup time depending on the unpowered period in clean air before
proceeding with the zero calibration and span adjustment. Refer to ‘<Warmup times for hot-wiresemiconductor type sensors>’ below for warmup times.
 The reading may change even for combustible gases other than the detection target gas.
 Readings may fluctuate in the presence of fluctuations (e.g., temperature and humidity) in the installation
location.
 When oxygen concentrations fall, the readings may also fall.
 Some interference may occur in the presence of highly thermally conductive gases such as CO2, Ar, andHe in high concentrations as base gases.
 When low vapor pressure gases are detected by aspiration, the gas may condense when aspirated fromwarmer areas and detected in cooler areas, or blockages may occur in sintered alloy. Keep vapor
pressure in mind when using the product.
 Perform maintenance if a warning appears while the life assessment or self-diagnostic function is active.
 Use the combustible gas sensor adapter when calibrating. Calibration accuracy may be impaired without
the combustible gas sensor adapter.
 Indication accuracy may degrade in situations in which temperatures fluctuate significantly (±20 °C or
greater) above or below the ambient temperature in which zero calibration or span adjustment was
performed. If this occurs, repeat zero calibration or span adjustment.
 There may be fluctuations in readings if the product receives strong shocks from outside or is subjected
to vibrations. If this occurs, perform zero calibration and span adjustment.
 The zero point may fluctuate if the sensor comes into contact with high-concentration gas continuously
for extended periods. If this occurs, perform zero calibration and span adjustment.
 Readings may fall in environments where gas is continuously present.
 The calibration value may become offset if gas is detected at levels exceeding the F.S. value. Enabling
the sensor protection function will help minimize these effects if there is any possibility of exposure to gas
at levels exceeding the F.S. value. However, if the sensor protection function is enabled, detection is notpossible after the F.S. value has been exceeded until it is reset, as the power to the sensor is cut off.
Reset from the sensor protection state in an environment with clean air.
If the sensor protection state is left in place for extended periods (one day or longer), warm up for aperiod of time corresponding to the sensor protection period. (Enabling the sensor protection function
also enables the over locking function.) The sensor may be hot during replacement. Be careful to avoid burns when replacing the sensor. If thesensor is hot, turn off the power and wait for it to cool.
 Depending on the conditions and length of time for which the power was turned off, the reading maychange when the power is turned on, even after the warmup time (three minutes) has elapsed. If thisoccurs, wait until the reading returns to zero.
 The warranty period for SHF sensors is three years, regardless of detection target gas.

165 / 175

10. Product Specifications

10-3 Detection target gases for individual detection principles<Hot-wire semiconductor type sensor warmup times>
Time turned off
Under 10 minutes
Under 1 hour
Under 24 hours
Under 72 hours
Under 10 days
Under 1 month
Under 3 months
3 months or more

Warmup time
SHF-8603
Other SHF sensors
At least 10 minutes At least 1 hour
At least 30 minutes At least 2 hours
At least 1 hour
At least 4 hours
At least 4 hours
At least 24 hours
At least 2 days
At least 2 days
At least 7 days
At least 7 days
At least 14 days
At least 14 days
At least 1 month
At least 1 month*Note that warmup times differ between the SHF-8603 and other SHF sensors.

166 / 175

10. Product Specifications

10-3 Detection target gases for individual detection principles

10-3-5 Electrochemical type
Sensor model

ESF-A24A

ESF-A24P

ESF-A24R

ESF-A24RH*1

Gas name

NitrogendioxideCarbonmonoxideHydrogensulfideHydrogensulfideGas
symbolF.S.

1 digitFirst

Second

Alarm

Alarm

setpoint

setpoint

Calibration
gas

OperatingOperatingtemperature range

humidity range(no sudden changes)(no condensation)

Years ofwarranty

NO2

15 ppm0.1 ppm

5.0 ppm

10.0 ppm

NO2−40 - 70 °C

20 - 90 %RH

3 yearsCO

150 ppm

1 ppm

50 ppm100 ppmCO−40 - 70 °C

20 - 90 %RH

3 years

H2S

100 ppm

1 ppm

20 ppm40 ppmH2S−40 - 70 °C

20 - 90 %RH

3 years

H2S

30 ppm0.2 ppm

10 ppm20 ppmH2S−40 - 70 °C

40 - 95 %RH

3 years

ESF-B22

AmmoniaNH3

75 ppm

0.5 ppm

25 ppm50 ppmNH3−40 - 70 °C

30 - 80 %RH

3 years*2

ESF-B22

AmmoniaNH3

150 ppm

0.5 ppm

50 ppm100 ppm

NH3−40 - 70 °C

30 - 80 %RH

3 years*2

ESF-B22

AmmoniaNH3

400 ppm

1 ppm

25 ppm300 ppm

NH3−40 - 70 °C

30 - 80 %RH

3 years*2

ESF-X24P2

Oxygen

O2

25 %

0.1 %

18.0 %

18.0 %

N2−40 - 70 °C

20 - 90 %RH

3 years

ESF-C92

ChlorineCL2

1.5 ppm

0.01 ppm

0.5 ppm

1.0 ppm

CL2−20 - 70 °C

30 - 80 %RH

3 years

ESF-C92

Chlorine

CL2

3 ppm

0.02 ppm

1 ppm

2 ppm

CL2

−20 - 70 °C

30 - 80 %RH

3 years

ESF-C92

Chlorine

CL2

10 ppm0.1 ppm

3 ppm

10 ppmCL2−20 - 70 °C

30 - 80 %RH

3 years*1: Sensor for high humidity.
*2: 3 years for use in a room temperature environment, and 2years for use under other conditions.

NOTE (1) Precautions for product storage and distribution
・Store the sensor in the sensor container.
 (2) Precautions for calibration
・Use the calibration cap for SD-3EC/ECS/ECB.
・Keep the flow rate at 0.5±0.1L/min.
・Perform zero and span calibration in a normal atmosphere.
・Use air or N2 as balance gas.
・Use N2 for zero calibration of the O2 sensor.
 (3) General operating precautions
・If the sensor is to be used for a long period of time in an environment outside the -25 to 55°C range,
allow it to fully acclimate to the operating environment before calibrating it.
・Indicator accuracy may be degraded when used in a high or low humidity environment.
・The response may become slow at low temperatures.
・The temperature range of 55 to 70℃ should be used for a total of one week.
・When calibrated at high or low temperatures, large temperature changes may cause a drop inindication accuracy.
・Sudden changes in temperature, humidity, or pressure may cause fluctuations in the indication.
・Diffusion type detectors may be affected by wind velocity due to the characteristics of the gas.
・If a warning message is displayed while using the life-time diagnosis or self-diagnostic function,
maintenance should be performed.
 ・The warranty period for ESF sensors varies for each sensor model. Refer to the table above.

167 / 175

11. Appendix

11-1 Detection principle

11

Appendix11-1 Detection principle
11-1-1 Non-dispersive infrared absorption type (Infrared type)<Sensor overview>
This gas detection sensor relies on the fact that many gases absorb infrared radiation. It detects the presence ofa detection target gas by irradiating a measurement cell with infrared and detecting variations caused by target
gas absorption of infrared. It continuously detects all infrared within a specific waveband without dividing(dispersing) infrared into differing wavelengths.

<Sensor structure and principle>
 Structure
A measurement cell and optical filter are positioned between the infrared emitter and the infrared sensor.
Infrared light from the infrared emitter passes through the measurement cell and optical filter before being
detected by the infrared sensor. The optical filter selectively allows the passage of infrared light in the
waveband absorbed by the detection target gas.
 Principle
When the detection target gas is introduced into the measurement cell, it absorbs infrared light, reducing theamount of infrared light detected at the infrared sensor. Based on this principle, a number of samples ofdetection target gas of known concentration is introduced to calculate the correlation (calibration curve)
between infrared reduction and the concentration of the detection target gas. The calibration curve can beused to determine the gas concentration from the measured infrared reduction when an unknown
concentration of detection target gas is introduced.
<Structuree diagram><Calibration curve (example)>

Infrared light

Infrared light

Detection
target gas

Detection
target gas

Infrared reduction

MirrorOptical filter
Detection target gas
concentration
Infrared emitter

Infrared sensor

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11. Appendix

11-1 Detection principle

11-1-2 New ceramic type (catalytic type)<Sensor overview>
This uses an ultrafine particle (new ceramic) oxidation catalyst to detect gas concentrations over a wide range,from low concentrations (ppm) up to the lower explosive limit (LEL). This revolutionary gas detection sensor wasdeveloped by RIKEN KEIKI and specifically designed to detect combustible gases.

<Sensor structure and principle>
 Structure
The new ceramic sensors consist of a detecting element and a compensating element. (Some sensors do
not have a compensating element.) The detecting element consists of an ultrafine particle oxidation catalyst(new ceramic) that reacts with combustible gases sintered on top of a precious metal coil. This undergoes a
combustion reaction in the presence of the detection target gas.
The compensating element consists of a material inert to combustible gases sintered on top of a precious
metal coil. This compensates for atmospheric effects.
 Principle
When combustible gas burns on the surface of the detecting element heated to between 300 °C and 450 °C
by the precious metal coil, this increases the temperature of the element. This temperature variation results inchanges in the resistance of the precious metal coil that makes up the element. These variations inresistance are essentially proportional to gas concentrations. The resistance variation can be extracted as a
voltage using a bridge circuit to calculate the gas concentration.
<Sensor element diagram>Compensating element
・・・Compensates for atmospheric effects.

Detecting element
・・・Detects gas.
Oxidation catalyst +alumina carrier

Glass +
alumina carrier

Precious metal coil

Precious metal coil
0.5 mm - 1.4 mm

0.5 mm - 1.4 mm
0.8 mm - 1.4 mm

0.8 mm - 1.4 mm<Bridge circuit>
Element temperature
decreases.
Resistance decreases.

Element temperature
increases.
Resistance increases.

Compensating
element

Detectingelement+
V-

Resistance ofrheostat arm R

Sensor voltage Vs

169 / 175

Sensor output

11. Appendix

11-1 Detection principle

11-1-3 Semiconductor type
<Sensor overview>
This method detects gas concentrations from variations in resistance that occur when a metal oxide
semiconductor comes into contact with the detection target gas. This general-purpose gas detector sensor isideal for detecting a wide range of gases, from toxic gases to combustible gases.

<Sensor structure and principle>
 Structure
The sensor consists of a metal oxide semiconductor (SnO2) formed around a heater coil and alumina tube.
The alumina tube has two gold electrodes at each end to measure semiconductor resistance.
 Principle
Oxygen from the atmosphere is adsorbed as O- and O2- to the surface of the metal oxide semiconductor
heated to between 350 °C and 400 °C by the heater coil. The semiconductor maintains a constantresistance. If a methane or other such gas comes into contact with this surface and becomes chemicallyadsorbed, the oxygen is oxidized and released by the adsorbed O2- ions.
The following chemical reaction occurs here at the sensor surface:
CH4 + 4O2- → CO2 ＋ 2H2O ＋ 8eIn other words, as methane gas is adsorbed to the sensor surface removing adsorbed oxygen, the increasein free electrons inside the sensor reduces the resistance. This variation in resistance can be measured andused to calculate the gas concentration.
<Sensor element diagram>

Gold electrodes

Metal oxide
semiconductor<Drive circuit>
Zero calibrator

DC power
sourceDetectingelement

Heater coil
Alumina tube

Lead wires

HeaterVoltageregulator

H2O

H2Signal amplifier

Span adjuster
Load resistanceH2 + O2- → H2O + 2e-

170 / 175

Indicator

11. Appendix

11-1 Detection principle

11-1-4 Hot-wire semiconductor type
<Sensor overview>
This sensor type detects gas concentrations based on variations in the resistance of a platinum coil integrated
with a metal oxide semiconductor whose resistance changes when it comes into contact with a gas. The highsensitivity low-concentration detection gas sensor is configured simply as a detecting element of metal oxide
semiconductor sintered around a platinum coil.

<Sensor structure and principle>
 Structure
The sensor consists simply of a detecting element formed of a metal oxide semiconductor sintered around aplatinum coil.
 Principle
The resistance (R) of the detecting element is the combined resistance of the semiconductor resistance (RS)and the platinum coil resistance (RH).
The detecting element is heated to between 300 °C and 400 °C by the platinum coil and maintains constantresistance. If methane or another such gas comes into contact with the detecting element, oxygen adsorbed
to the surface of the metal oxide semiconductor is released, increasing the number of free electrons inside
the semiconductor and reducing the resistance of the semiconductor. This reduces the resistance of theentire detecting element. These variations in resistance are measured as a voltage and used to calculate gas
concentrations.

<Detecting element diagram>Metal oxide
semiconductor<Drive circuit>

Platinum coil
0.5 mm - 1.4 mm

Constant
current

0.8 mm - 1.4 mm

171 / 175

Detecting element
Semiconductor material
Resistance changes
Sensor output

Indicator

11. Appendix

11-1 Detection principle

11-1-5 Electrochemical type
<Sensor overview>
This sensor type detects a gas concentration in the form of a current generated when the detection target gas iselectrolyzed on electrodes maintained at constant potential. This is the most effective gas sensor for detecting
toxic gas. Gases can be selectively detected by selecting a specific potential.

<Sensor structure and principle>
 Structure
The sensor consists of an electrode (working electrode) formed of a precious metal catalyst on a gas
permeable membrane, a reference electrode, and a counter electrode, all enclosed in a plastic container
filled with electrolyte solution.
 Principle
A potentiostat circuit is used to maintain a constant potential between the working electrode and referenceelectrode. The detection target gas passes through the gas permeable membrane and undergoes
electrolysis reaction on reaching the working electrode. A side reaction also occurs at the counter electrodeso that the same amount of electric current flows through it as that produced at the working electrode.
Example: In the case of hydrogen sulfide (H2S), the following chemical reaction occurs:
Working electrode:H2S + 4H2O → H2SO4 + 8H+ + 8e- (e- is an electron)
Counter electrode:2O2 + 8H+ + 8e- → 4H2O
The current generated here is proportional to the gas concentration. The gas concentration can therefore be
determined by measuring the current flowing through the working electrode<Structure diagram>
Potentiostat circuit
Referenceelectrode

Working electrode

Detection
target gas

Electrolyte

Gas permeable
membrane

Catalyst

172 / 175

Counter
electrodeContainer

11. Appendix

11-2 Terminology

11-2 Terminology
TermDefinition

Initialization

This function prevents alarms from being issued for a while after the power isturned on.
This prevents alarms from being issued, as the output from the detector
fluctuates for a while after the power is turned on.

Full scale

The maximum value of the detection range

Calibration

This refers to the process of checking the product reading against a calibrationgas.
The process includes adjusting the product reading to match the concentrationof the calibration gas.

Zero suppression

This function is used to hide (suppress) reading fluctuations below a set lower
limit to minimize sensor output fluctuations not caused by gas, such astemperature and humidity fluctuations and noise effects.

Alarm delay time

This function temporarily suspends immediate alarm activation to prevent false
alarms caused by external noise, even if the reading reaches an alarm setpoint.

InhibitThis function pauses gas detection—for example, when the product isundergoing maintenance. It is also sometimes referred to as point skipping.

%

Unit used to express the percentage of a target gas contained in a given
volumeppm

Unit used to express the parts per million of a target gas contained in a given
volume%LEL

Unit for combustible gases in which the lower explosive limit (LEL) of the target
gas is set to 100 % (Example: For methane, 5 % concentration by volume
corresponds to 100 %LEL.)

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Product warranty

Product warranty
1. If a fault occurs with the product within three years of the purchase date, with use under normal conditions incompliance with precautions indicated in the operating instructions or on labels affixed to the main unit, repairs
will be cost free.
2. Contact our sales department or your nearest sales office for information on repairs, maintenance, or after-sales
service.
3. You will be charged for costs incurred as the result of service rendered in remote locations.
4. Fees will be charged for repairs in the following cases, even during the warranty period:(a) Fault or damage is attributable to incorrect use or improper repairs or modifications.
(b) Fault or damage following repairs or modifications made at locations other than Riken Keiki or a service
agent specified by Riken Keiki.
(c) Fault or damage is attributable to moving, transporting, falling, dropping, or improper storage occurring
after purchase.
(d) Fault or damage is attributable to external factors, including natural phenomena such as fire, earthquake,flood, or lightning; pollution; abnormal voltage; use of power sources outside of rated ranges (voltage,
frequency), etc.
(e) The fault is attributable to a factor external to this product.
(f) When replacing consumables (batteries, fuses, etc.).

Sensor warranty
1. Replacements will be provided at no charge if a fault occurs within three years of the purchase date or the dateon which a sensor was replaced for a fee (excluding certain sensors), with use under normal conditions incompliance with precautions indicated in the operating instructions or on labels affixed to the main unit.
For information on the length of the warranty for each sensor model, refer to ‘10- 3 Detection target gases
for individual detection principles’.
A precondition of the warranty for sensors requires sensors to be serviced once or more a year from the purchasedate or the date on which a sensor was replaced for a fee.
2. Contact our sales department or your nearest sales office for information about repairs, maintenance, or aftersales service.
3. You will be charged for costs incurred as the result of replacements performed in remote locations.
4. Fees will be charged for replacements made in the following cases, even during the warranty period.
(a) If the product is used in disregard of the precautions provided in the operating instructions, on labels
affixed to the main unit, or elsewhere.
(b) Fault or damage following repairs or modifications made at locations other than Riken Keiki or a service
agent specified by Riken Keiki.
(c) Fault or damage is attributable to moving, transporting, falling, dropping, or improper storage occurring
after purchase.
(d) Fault or damage is attributable to external factors, including natural phenomena such as fire, earthquake,flood, or lightning; pollution; abnormal voltage; use of power sources outside of rated ranges (voltage,
frequency), etc.
(e) The fault is attributable to a factor external to this product.
(f) Changes in the gas sensitivity of the sensor, fault, or damage are due to the effects of coexisting gases(acidic gases, alkaline gases, alcohol, silicone, etc.) in the installation environment.

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Revision History

Revision History
Issue

Revision details

Issue date

0First issue (PT2E-2874)

7/14/2023

1

1-2-1 Modification of models and codes
3-1-5 Addition and correction of special accessories (optional)
4-1-2 Added description of cable and power supply installation
6-4-1, 6-4-2 Correction of external output operation table
7-7, 8-1, 10-3-5 Modifications due to addition of ESF sensor lineup

9/5/2023

2

3-1-5 Addition of tag plate with wire chain
4-11 Adding a lightning arrestor installation

12/26/2023

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