PT2E-19613

Smart transmitter/Gas Detector Head

SD-1DRI
Operating Manual(PT2E-196)(PT2-196)

Operating Precautions
This detector is a gas detector that detects combustible gases in the air and triggers a gas alarm.
The gas detector is a safety unit, not an analyzer or densitometer which performs quantitative/qualitative
analysis/measurement for gases.
Please fully understand the following points before using it, so that it can be used properly.
1.

This detector may be interfered by gases and vapors other than the gas to be detected.
Please note that the alarm may be triggered by interference. In addition, it may be fluctuated byenvironmental (temperature, humidity, etc.) changes in the installation site.

2.

The alarm must be set within a range where the performance of the detector can be ensured.
In facilities compliant with the High Pressure Gas Safety Act, an alarm setting below our standard
alarm setpoint may trigger a false alarm.

3.

This is a safety unit, not a control unit.
The alarm contact output of the detector must be used for an external alarm lamp/buzzer, while thealarm signal output must be used for an indicator or external recorder.
If these outputs are used to control other units, we shall not be responsible for any malfunctions.

4.

For maintenance of the detector, it must go through a regular maintenance, including replacement andadjustment of the regular replacement parts as specified in the operating manual. In addition, because
this is a safety unit, it is recommended that a regular maintenance and a gas calibration are performed
every six months in accordance with the regulations.

Operating Precautions<Contents>
1 Outline of the Product ......................................................................................................... 1
1-1. Preface .............................................................................................................................. 1
1-2. Purpose of use .................................................................................................................. 1
1-3. Definition of DANGER, WARNING, CAUTION, and NOTE ............................................... 1
1-4. Method of confirmation for Standards and Explosion proof specification .......................... 22 Important Notices on Safety................................................................................................ 3
2-1. Danger cases .................................................................................................................... 3
2-2. Warning cases .................................................................................................................. 4
2-3. Precautions ....................................................................................................................... 5
2-4. Safety Information ............................................................................................................. 6
3 Product Components .......................................................................................................... 9
3-1. Gas detector and standard accessories ............................................................................ 9
3-2. Names and functions for each part ................................................................................... 10
3-3. Block diagram ................................................................................................................... 11
4 How to Use ......................................................................................................................... 124-1. Before using the detector .................................................................................................. 12
4-2. Precautions for installation points...................................................................................... 12
4-3. Precautions for system designing ..................................................................................... 13
4-4. How to install ..................................................................................................................... 15
4-5. Installation procedure ........................................................................................................ 16
4-6. How to wire ....................................................................................................................... 18
4-7. How to tube ....................................................................................................................... 22
5 How to Operate................................................................................................................... 23
5-1. Preparation for start-up ..................................................................................................... 23
5-2. Basic operating procedures............................................................................................... 23
5-3. How to start the detector ................................................................................................... 24
5-4. Modes ............................................................................................................................... 25
5-5. Maintenance mode(User) .................................................................................................. 26
5-6. How to exit ........................................................................................................................ 28
6 Operations and Functions ................................................................................................... 29
6-1. Gas alarm activation ......................................................................................................... 29
6-2. Fault alarm activation ........................................................................................................ 30
6-3. External output operation .................................................................................................. 31
6-4. Other functions .................................................................................................................. 32
7 Maintenance ....................................................................................................................... 33
7-1. Maintenance intervals and items ....................................................................................... 33
7-2. Maintenance mode (Regular maintenance) ...................................................................... 35
7-3. Gas calibration method ..................................................................................................... 42
7-4. Parts replacement ............................................................................................................. 45
8 Storage, Relocation and Disposal....................................................................................... 47
8-1. Procedures to store the detector or leave it for a long time ............................................... 47
8-2. Procedures to relocate the detector or use it again ........................................................... 47
8-3. Disposal of products .......................................................................................................... 47
9 Troubleshooting .................................................................................................................. 48
10 Product Specifications ...................................................................................................... 50
10-1. List of specifications ........................................................................................................ 50
10-2. Detection principle ........................................................................................................... 55
11 Definition of Terms ............................................................................................................ 56-1-

1 Outline of the Product1-1. Preface

1

Outline of the Product1-1. Preface
Thank you for choosing our smart transmitter/gas detector head SD-1DRI. Please check that the model
number of the product you purchased is included in the specifications on this manual.
This manual explains how to use the detector and its specifications. It contains information required forusing the detector properly. Not only the first-time users but also the users who have already used the
product must read and understand the operating manual to enhance the knowledge and experience before
using the detector.
Product specifications may be abbreviated in this document as follows.
Japan Ex specification ： Japan specification
ATEX / IECEx specification ： Export specification

1-2. Purpose of use
 The detector is a fixed type gas detector head that detects leak of combustible gases and that performs thealarm activation when the gas concentration is over the setting value.
This detector is a safety unit, not an analyzer or densitometer which performs quantitative/qualitative
analysis/measurement for gases. Please fully understand the features of the detector before using it, sothat it can be used properly.
 The detector detects abnormalities in the air caused by presence of gases or other reasons (leak) with thebuilt-in gas sensor. The concentrations of detected gases are displayed on the seven-segment LED.
 An external pump etc. outside the detector introduces gas to perform gas detection.
 The detector has a built-in alarm contact and can be used either as a gas alarm, fault alarm, or common(gas, fault) alarm.
 The detector outputs gas concentration in 4 – 20 mA.

1-3. Definition of DANGER, WARNING, CAUTION, andNOTE
DANGERWARNINGCAUTION
NOTE

This message indicates that improper handling may cause serious
damage on life, health or assets.
This message indicates that improper handling may cause serious
damage on health or assets.
This message indicates that improper handling may cause minor
damage on health or assets.
This message indicates advice on handling.

-1-1 Outline of the Product1-4. Method of confirmation for Standards and Explosion proof specification

1-4. Method of confirmation for Standards andExplosion proof specification
This instrument has some specification depends on standard and explosion proof certificate. Pleaseconfirm the detector specification before using. Please refer Declaration of Conformity that is at the end of
this manual if you have CE marking type. You can confirm instrument specification to see name plate as
follows.
Japan Ex certificate

Ex marking

CE marking

ATEX/IECEx, CE marking type name plate

Japan Ex type name plate-2-2 Important Notices on Safety

2-1. Danger cases

2

Important Notices on
Safety2-1. Danger cases
DANGER<About explosion-proof>
The window plate material is a polycarbonate resin. Do not use organic solvents and alkali types (liquid orvapor). It may cause the color and shape of the window plate to be changed.
 Do not open the lid when applying current.
 Do not attempt to repair the detector.
 For the lid, use hexagon socket head bolts specified by RIKEN KEIKI.
 Do not apply a strong force or shock to the window plate. The explosion-proof performances may be
deteriorated due to damages. The explosion protection conditions for the detector is "low (2J)"
possibility of mechanical damage.
 Ambient temperature:
Export Specifications: -20 to +60°C
Japan Specifications: -20 to +53°C(The ambient temperature on explosion-proof certification is described above and it indicates thetemperature range which can maintain the explosion-proof performance and not the productperformance, see “10-1. List of specifications” for details.)
 Do not replace parts at your sole discretion but contact RIKEN KEIKI if the transparent window has acrack or the explosion-proof joint surface is abnormal, or the clamping screw or bolt is changed, lostetc.
 Do not repair the explosion-proof joint surface.
 Be careful not to hit sharp tools against the window plate.
 Nitrile rubber (NBR) is used for the cable gland component. The organic solvents and alkalis (liquid
or vapor) present in the measurement environment may not be able to maintain the explosion-proof
performance.

-3-2 Important Notices on Safety

2-2. Warning cases

2-2. Warning cases
WARNING
Power supply
Before turning on the detector, always check that the voltage is properly applied. Do not use an unstable
power supply because it may cause malfunctions.
Need of grounding circuit
Do not cut the grounding circuit or disconnect the wire from the grounding terminal.
Defects in protective functions
Before starting the detector, check the protective functions for defects. When seeming defects are foundin the protective functions, such as protective grounding, do not start the detector.
Tubing
The detector is designed to draw gases around it under the atmospheric pressure. Be sure that
excessive pressure is not applied to the sampling inlet and outlet (GAS IN, GAS OUT) of thedetector. Detected gases must be exhausted from the detected gas exhausting outlet (GAS OUT) to
which an exhaust tube is connected, to a point regarded as a safe place.
External connection
Before connecting the detector to the external control circuit, securely connect it to a protective
grounding circuit.
Zero adjustment in the atmosphere
When the zero adjustment is performed in the atmosphere, check the atmosphere for freshness before
beginning the adjustment. If other gases exist, the adjustment cannot be performed properly, thus
leading to dangers when the gas leaks.
Response to a gas alarm
Issuance of a gas alarm indicates that there are extreme dangers. Take proper actions based on yourjudgment.

-4-

2 Important Notices on Safety

2-3. Precautions

2-3. Precautions
CAUTION
Do not use a transceiver near the detector.
Radio wave from a transceiver near the detector or its cables may disturb commands. If a transceiver isused, it must be used in a place where it disturbs nothing.
To restart the detector, wait for five seconds or more before doing it.
Restarting the detector within five seconds may cause errors.
Verify that the flow rate corresponds to the specified flow rate before using the detector.
If it does not correspond to the specified flow rate, gas detection cannot be performed properly.
Check whether the flow rate is unstable or lost.
Attach the dust filter before using the detector.
Before using the detector, attach the specified filter to prevent disturbances by possible gas
adsorption or air dust.
A dust filter to be used varies depending on the gas to be detected. For more information on dust
filters, please contact RIKEN KEIKI.
Observe the operating restrictions to prevent condensation inside the tube.
Condensation formed inside the tube causes clogging or gas adsorption, which may disturb
accurate gas detection. Thus, condensation must be avoided. In addition to the installation
environment, carefully monitor the temperature/humidity of the sampling point to prevent
condensation inside the tube. In particular, when detecting a gas which is dissolved into water andcorrodes contacted materials, such as a strong acid gas, the gas is undetectable and furthermore
may corrode internal parts. Please observe the operating restrictions.
Do not use the external output of the detector to control other units.
This is not a control unit. It is not allowed to use the external output of the detector to control other units.
Do not disassemble/modify the detector, or change the settings if not necessary.
Disassembling/Modifying the detector will invalidate the warranty of the performance. Changing thesettings without understanding the specifications may cause alarm malfunctions. Please use the detector
properly in accordance with the operating manual.
Avoid applying organic solvents and others to the window plate for a long time.
The window plate material is a polycarbonate resin. When organic solvents (liquid or highly-concentrated
vapor) and others are applied to the plate for a long time, its color and shape may be changed.
Do not forget to perform a regular maintenance.
Since this is a safety unit, a regular maintenance must be performed to ensure safety. Continuing to use
the detector without performing a maintenance will compromise the sensitivity of the sensor, thus
resulting in inaccurate gas detection.

-5-

2 Important Notices on Safety

2-4. Safety Information

2-4. Safety Information
Necessary information for explosion proof construction of Model SD-1DRI.
The Model SD-1DRI is a fixed mount, continuous-monitoring detector head and provides a 4-20mA signal
which indicates the target gas reading for use by a gas monitoring controller, recording device, or
programmable controller.
There is one point of contact and works by gas warning or trouble or both by setting.
<ATEX/IECEx Specifications>Technical Data
(Protection Method)(Certificate Numbers)(Group)(Category)(Type of Protection and Marking code)(Equipment Protection Level)(Ambient Temperature)(Electrical Data)(Applicable Standard)(Manual Number)

Flameproof enclosure “d”
IECEx DEK 24.0004X
DEKRA 24ATEX0004 X
II
2G
Ex db ll C T6
Gb
-20C to +60C
Supply voltage: 24VDC 85mA (Typ.)
Signal output:( 4 to 20 mA): 24VDC 22mA
Relay( Contact output): 30VDC or 250VAC 0.5A
IEC 60079-0: 2017，IEC 60079-1: 2014-06
EN IEC 60079-0: 2018，EN 60079-1: 2014
PT2E-196* The ambient temperature on explosion-proof certification is described above and it indicates thetemperature range which can maintain the explosion-proof performance and not the product performance,
see “10-1. List of specifications” for details
Specific conditions of “X”-mark:・The property class of the cover screws is at least A*-70.
・The plastic window is submitted to tests corresponding to the low risk of mechanical danger.
・The flameproof joints not intended to be repaired.

-6-

2 Important Notices on Safety

2-4. Safety Information

Installation
Installation Diagram
Hazardous Location(Zone 1)

Nonhazardous Location

Gas
Detector(SD‐1DRI)
Gas
Detector(SD‐1DOX)

Indicator etc.
24V

24V

GND

GND
Sig+

Sig+
RLY

CVVS Cable

-7-

RLY

2 Important Notices on Safety

2-4. Safety Information<Japan Ex Specifications>Technical Data
(Protection Method)

Flameproof enclosure(Explosion-proof class)

Ex d llC T6 X

(Ambient Temperature)-20C to +53C(Electrical Data)

Supply voltage: 24VDC 85mA
Analog signal output: 24VDC 22mA
Contact output (Contact capacity): 250VAC 0.5A (Load resistance)
30VDC 0.5A (Load resistance)(Applicable Standard)

JNIOSH-TR-NO. 43(2008)* The ambient temperature on explosion-proof certification is described above and it indicates thetemperature range which can maintain the explosion-proof performance and not the product performance,
see “10-1. List of specifications” for details
Installation
Installation Diagram
Hazardous Location(Zone 1)

Nonhazardous Location

Gas
Detector(SD‐1DRI)
Gas
Detector(SD‐1DOX)

Indicator etc.
24V

24V

GND

GND
Sig+

Sig+
RLY

CVVS Cable

-8-

RLY

3 Product Components

3-1. Gas detector and standard accessories

3

Product Components
3-1. Gas detector and standard accessories<Main Unit> (including a cable gland)【Export Specification】

Adapter(NPT 1/2 )Aspirator cap【Japan Specification】

Aspirator cap

Cable gland (G3/4)-9-

3 Product Components

3-2. Names and functions for each part

<Standard Accessories> Operating manual･･････････････････ one
 Dedicated handling lever (used for the wiring) ･･････････････････ one
 Dedicated control key････････ The supplied quantity depends on the number of units to be delivered.
1 to 10 unitsone
11 to 20 units
two
21 to 50 units
threeover 51 units
four

CAUTION
Use the supplied dedicated control key to operate the detector. If products other than these accessories
are used, key operations cannot be accepted properly.
Note that the control key is made of extremely strong magnet. Putting it close to a magnetic product,such as a credit card and ID card, may damage the stored data.

3-2. Names and functions for each part
(5) Power lamp

(6) Alarm lamp

(7) Fault lamp(3)  key(1) MENU/ESC key(8) Concentration
value display(4)  key(2) SET key(1)

MENU/ESC key(2)

SET key

(3)
(4)

 key
 key

(5)

Power lamp

(6)

Alarm lamp

(7)

Fault lamp

(8)

Concentration value
display

Used to enter the maintenance mode.
It is also used to cancel in a specific mode.
It is used for value confirmation and so on in a specificmode.
Used to switch menus or change a value (UP).
Used to switch menus or change a value (DOWN).
Power lamp.
Detection mode: It lights up in green.
Maintenance mode: It blinks in green.
Alarm lamp. It lights up in red when the alarm setpoint value
is reached.
Fault lamp. It lights up in yellow when an abnormality isdetected in the detector.
Displays the gas concentration and so on.

- 10 -

3 Product Components

3-3. Block diagram

3-3. Block diagram<Electric Diagram>

Power supply part
POWER INPUT (24 VDC)
Display(POWER) (ALARM) (FAULT)
Alarm contact controller
1.Gas alarm contact(ALARM)or
2.Fault contact (FAULT)
or
3.Select either gas alarm orcontact (ALARM/FAULT)

Controller(CPU)

Seven-segment LED(four-digit)
Magnetic operation part
(MENU/ESC) (▲) (▼) (SET)Contact activation
 De-energized(De-energized at a
normal state)
ON-ALARM (Closed
contact at an alarm

SensorTransmitter• 4 – 20 mA transmission- 11 -

4 How to Use

4-1. Before using the detector

4

How to Use
4-1. Before using the detector
Not only the first-time users but also the users who have already used the product must follow the operating
precautions.
Ignoring the precautions may damage the detector, resulting in inaccurate gas detection.

4-2. Precautions for installation points
CAUTION
This is a precision device. Because the detector may not provide the specified performance in someplaces (environments), check the environment in the installation point, and then take appropriate actions
if necessary.
Because the detector plays an important role for safety and disaster prevention, as many units of thedetector as needed must be installed in appropriate points.
Because points where gases leak and remain easily are different depending on the types of gases andthe working areas, please decide carefully installation points and the number of units to be installed.
Do not install the detector in a place with vibrations or shocks.
The detector consists of sensitive electronic parts. The detector must be installed in a stable place without
vibrations or shocks and it cannot drop.
Do not install the detector in a place exposed to water, oil or chemicals.
When selecting installation points, avoid a place where the detector is exposed to water, oil or chemicals.
Do not install the detector in a place where the range of operating temperatures is exceeded.
The detector must be installed in a stable place where the operating temperature is maintained and do notchange suddenly.
* For operating temperature range, see “10-1. List of specifications” for details.
Do not install the detector in a place exposed to direct sunlight or sudden changes in the temperature.
When selecting installation points, avoid a place where it is exposed to direct sunlight or radiant heat
(infrared rays emitted from a high-temperature object), and where the temperature changes suddenly.
Condensation may be formed inside the detector, or the detector cannot adjust to sudden changes in thetemperature.
Keep the detector (and its cables) away from noise source devices.
When selecting installation points, avoid a place where high-frequency/high-voltage exist.

- 12 -

4 How to Use

4-3. Precautions for system designing

Do not install the detector in a place where maintenance of the detector cannot be performed or wherehandling the detector involves dangers.
Regular maintenance of the detector must be performed.
Do not install the detector in a place where the machinery must be stopped when maintenance is performed
in its inside, where parts of the machinery must be removed to perform maintenance, or where the detector
cannot be removed because tubes or racks prevent access to it. Do not install the detector in a place where
maintenance involves dangers, for example, near a high-voltage cable.
Do not install the detector in machinery which is not properly grounded.
Before installing the detector in machinery, the machinery must be grounded properly.
Do not install the detector in a place where other gases exist around it.
The detector must not be installed in a place where other gases exist around it.

4-3. Precautions for system designing
CAUTION
An unstable power supply and noise may cause malfunctions or false alarms.
The descriptions in this section must be reflected on the designing of a system using the detector.
Using a stable power supply
The external output and alarm contact of the detector may be activated when the power is turned on, whenmomentary blackout occurs, or when the system is being stabilized. In such cases, use a UPS, or takeappropriate actions on the receiving side of output signals.
The detector must be provided with the following power supply.
Power supply
voltageAllowed time of
momentary blackout

Others24 VDC±10%: Terminal voltage of the detector
Up to 10 milliseconds(To recover from the momentary
blackout for 10 milliseconds or more,restart the detector.)
Do not use it with a power supply oflarge power load or high-frequency
noise.

Example of actions
To ensure continuous operation andactivation, install a UPS outside thedetector.
Example of actions
Use a line filter to avoid the noise
source if necessary.

Introducing protective measures against lightning
If cables are installed outside the factory/plant, or if internal cables are installed in the same duct as thecables coming from outside the factory/plant, "lightning" will cause problems. Because lightning acts as alarge emission source while cables act as a receiving antenna, devices connected to the cables may bedamaged.
Lightning cannot be prevented. Cables installed in a metal conduit or under the ground cannot becompletely protected from inductive lightning surge caused by lightning. Although complete elimination ofdisasters caused by lightning is impossible, the following protective measures can be taken.
Take appropriate measures in accordance with the importance of the facilities
and the environment.
Protection against  Provide protection by a lightning arrester (cable safety retainer).
(Although inductive lightning surge can be transmitted through the cable, it islightning
prevented by installing a lightning arrester before the field devices and central
processing equipment. For information on how to use a lightning arrester,
please contact the manufacturer.)
In addition to lightning, there are more sources of surge noise. To protect units
Groundingfrom these noise sources, the units must be grounded.
* The lightning arrester has a circuit to remove a surge voltage which damages field devices, so that signals
may be attenuated. Before installing a lightning arrester, verify that it works properly.

- 13 -

4 How to Use

4-3. Precautions for system designing

Proper use of alarm contact
The alarm contact of the detector is used to transmit signals to activate an external buzzer, an alarm lamp ora rotating lamp. Do not use the detector for controlling purpose (e.g., controlling the shutdown valve.)
The specifications for the alarm contact of the detector are based on the resistant load conditions. If
inductive load is used at the alarm contact, the following errors will occur easily because counterelectromotive force is generated at the contact.
 Deposition, defective insulation or defective contact at the relay contact
 Damage of any electric parts due to high-voltage generated inside the detector
 Abnormal operations by an out-of-control CPU

CAUTION
In principal, do not activate inductive load at the alarm contact of the detector. (In particular, never use theinductive load to activate a fluorescent lamp or motor.)
If inductive load is activated, relay it with an external relay (contact amplification). However, because thecoil of an external relay also involves inductive load, select a relay at a lower voltage (100 VAC or below),
and then protect the contact of the detector with an appropriate surge absorbing part, such as a CR circuit.

If load is to be activated, appropriate measures must be taken to stabilize the operation of the detector andprotect the alarm contact referring to the following information.
 Relay it with an external relay at a lower voltage of 100 VAC or below (contact amplification). At the sametime, the surge absorbing part SK1 suitable for the specifications must be attached to the external relay.
 In addition, the surge absorbing part SK2 must be attached to the loaded side of the external relay ifnecessary.
 It may be recommended that the surge absorbing part should be attached to the contact for certain loadconditions. It must be attached to an appropriate position by checking how the load is activated.
SD-1DRI- 14 -

4 How to Use

4-4. How to install

4-4. How to install<Installation Dimensions and Maintenance Space>

193mm

150mm

The following installation requirements must be met to install the detector.
 Attach the detector on the wall and others using four M5 screws.
 Tighten the hexagon socket head cap screws fixing the lid and the main body with the tightening torque of
215.6±24.5N･cm.
 When closing the lid of the detector, please wipe the screw and the mating surface of the main body andthe lid, and apply our company-specified grease.

CAUTION
Do not install the detector in a place where maintenance of the detector cannot be performed or wherehandling the detector involves dangers.
Regular maintenance of the detector must be performed.
Do not install the detector in a place where the machinery must be stopped when maintenance isperformed in its inside, where parts of the machinery must be removed to perform maintenance, orwhere the detector cannot be removed because tubes or racks prevent access to it. Do not install thedetector in a place where maintenance involves dangers, for example, near a high-voltage cable.

NOTE
・Our company-specified grease : BARRIERTA JFE 552 (manufactured by NOK KLUBER)
If you can not prepare the specified grease, use one that meets the following requirements.
1. Material does not harden due to deterioration
2. Volatile solvent-free
3. Material does not cause corrosion at the surface
4. Silicon-free
5. Validation of suitability depends on the specifications of grease manufacturer- 15 -

4 How to Use

4-5. Installation procedure

4-5. Installation procedure<Attaching External Cable>【Export Specification】
The export specification comes with adapter A (NPT 1/2) asstandard. Please prepare the Ex cable gland that is suitable for the adapter.
Adapter
Adapter(NPT1/2)(NPT1/2)【Japan Specification】
Cable gland, Rubber seal, Washer and Eccentric washer are mounted on SD-1DRI main body as shown
below.
Attach the parts :Pass a Cable (e.g. CVVS) through the Cable gland, Eccentric washer, Washer, and Rubber seal, anddrawn into detector inside. (For wire methods, see "4-6 How to wire".) When installing the cable gland, wipe
the cable gland mounting part, the hexagon socket set screw, the grounding screw, and the cable gland andwipe the specified grease.
Tightens Cable gland, and then tightens hexagon socket set screw (M4×6), and fix cable gland.

Grounding screw
Hexagon socket set screw（M4×6）
Cable gland mounting part
Rubber seal

Main unit case

WasherRubber seal

Daub screw with grease
Cable gland(G3/4)

WasherEccentric washer
Cable（CVVS etc.）

Eccentric

Cable gland(G3/4)

Please mind directionof Eccentric washer

Cable gland section view
Washer side

Cable gland side

WARNING Do not replace parts at your sole discretion but contact RIKEN KEIKI if the transparent window has acrack or the explosion-proof joint surface is abnormal, or the clamping screw or bolt is changed, lost etc.

CAUTION Tighten 40 Nꞏm or larger torque value to ensure the tightening cable gland and seal plug.
 Tighten the hexagon socket head cap screws fixing the cable gland with the tightening torque of 107.8±12.7N･m.
- 16 -

4 How to Use

4-5. Installation procedure

NOTE
・Our company-specified grease : BARRIERTA JFE 552 (manufactured by NOK KLUBER)
If you can not prepare the specified grease, use one that meets the following requirements.
1. Material does not harden due to deterioration
2. Volatile solvent-free
3. Material does not cause corrosion at the surface
4. Silicon-free
5. Validation of suitability depends on the specifications of grease manufacturer- 17 -

4 How to Use

4-6. How to wire

4-6. How to wire
CAUTION Be careful not to damage the internal electronic circuit when wiring. In addition, be careful not to apply
stresses on the detector when (overweight) cables are installed.
 The power cables and signal cables must not be installed together with the motor power cables, etc.
When these cables must be installed together for unavoidable reasons, put the power cables andsignal cables in a metal conduit. The conduit must be connected to a grounding circuit.
 When stranded wires are used, prevent wires from contacting each other.
 Use the dedicated handling lever to wire.
 Use appropriate cables to wire.

<Recommended Cable>
3-wire (when the contact is not used)
5-wire (when the contact is used)

CVVS1.25 mm2 or 2.0 mm2- 3-core
CVVS1.25 mm2 or 2.0 mm2 -5-core<Parts. length table of outside conductor lead-in> (Japan specification)
Cable overall outer
diameter(mm)Rubber seal innerdiameter(mm)Washer innerdiameter(mm)Clamp innerdiameter(mm)From Φ9.6 to Φ10.5

Φ11

Φ12

Φ10.8

From Φ10.5 to Φ11.5

Φ12

Φ12

Φ11.8

From Φ11.5 toΦ12.5

Φ13

Φ14

Φ12.8

From Φ12.5 toΦ13.0

Φ13.5

Φ14

Φ13.8

φ23

- 18 -

4 How to Use

4-6. How to wire

NOTE

 The following table shows an example of overall outer diameters of cables. Use them for reference.
The overall outer diameters must be checked because they somewhat vary between manufacturers.
Number of core

CVV 1.25 mm2

CVV 2 mm2

CVVS 1.25 mm2

CVVS 2 mm2

2

Φ9.5

Φ10.5

Φ10.0

Φ11.0

3

Φ10.0

Φ11.0

Φ10.5

Φ11.5

4

Φ10.5

Φ11.5

Φ11.0

Φ12.0

5

Φ11.5

Φ12.5

Φ12.0

Φ13.0

6

Φ12.5

Φ13.5

Φ13.0

Φ14.0

<Figure of Terminal Plate>

24 VDC
4 - 20mA

DC+

1- (Common)

2

Sig+

3

Contact

4

Contact

5

Groundingterminal<Specifications of Terminal Plate>Specifications of terminal plate Rated voltage: 250 VAC
 Rated current: 12 A
However, it depends on cables to be used.
Connection conditions
 Cables: 0.25 - 2.5 mm2
 Bare wire length: 8 - 9 mm
 Connecting tool: Dedicated handling lever (accessory) or driver (edge 3.5 x 0.5 mm)- 19 -

4 How to Use

4-6. How to wire

CAUTION
The specified bare wire length must be observed when the wire insulation is peeled off.
Improper clamping of the wire due to a shorter bare wire length may cause defective electrification or
heating.
Damaging the wire insulation due to a shorter bare wire length may cause defective electrification or
heating.
Exposing the wire due to a longer bare wire length may cause defective insulation or a short circuit.
Be careful not to break up the wire. If the wire is broken up when inserted to the terminal, this may cause
defective insulation or heating.

Compatible bar terminal
For a bar terminal, the following items are available.
 Bar terminal (ferrule): Model 216 Series (manufactured by WAGO)
 Crimping tool: Model VarioCrimp 4 (206-204) (manufactured by WAGO)

CAUTION
A bar terminal of the specified model must be used. Using other bar terminals invalidates the warranty ofthe performance.

<How to Connect to Terminal Plate>
When cables are connected to the connectors, use the dedicated lever or a flathead screwdriver to do it asshown below.

CAUTION
The right tools must be used.
In principal, one wire can be connected to one wiring hole.
When the wire is inserted into the driver slot by mistake, it does not contact the conductive part. This may
cause defective electrification or heating.
When the wire is inserted under the spring by mistake, it does not contact the conductive part. This may
cause defective electrification or heating.

NOTE<How to Use the Dedicated Handling Lever>Push the lever with your finger
to lower the spring in its inside.

While holding down the lever, insert the wire into the(round) wiring hole until it reaches the deepest point.
Once the lever is released, the wire is secured.

To check whether the wire is connected securely, pull the wire gently. (Do not pull the wire strongly.)- 20 -

4 How to Use

4-6. How to wire

<Grounding>Connect the detector to your grounding terminal with the external terminal.

WARNING Before turning on the detector, do not forget to connect it to a grounding terminal.
 For stable operation of the detector and safety, it must be connected to a grounding terminal. Do notconnect the grounding wire to a gas pipe.
 The grounding must be made as D type grounding (below 100 Ω of grounding resistance).
 For the grounding wire, use cable lugs to safely connect it to a grounding terminal without loosenessor twist.
 Use ring terminals to connect the grounding terminal with the ground and use the grounding wire withcross-sectional area of 4 mm2 or more for the external grounding terminal.

<Wiring Example>
Connecting to the indicator
SD-1DRI
1 2 3 4 5
RM-5003, etc.
+24 V
GND
Sig

Connecting to the upper unit (DCS, PLC)
SD-1DRI
1 2 3 4 5Power supply(24 VDC)

Relay terminal
plate

+
-

Upper unit
(DCS, PLC)+

- 21 -

4 How to Use

4-7. How to tube

4-7. How to tube
The detector has a Rc1/8 thread inside of the sampling inlet/outlet (GAS IN, GAS OUT), to which one of the"Bs", or "SUS" unions is normally attached. Because their material varies depending on the gas to be used,
please specify the appropriate unions.
The compatible tube is a tube of Φ6 (OD) - Φ4 (ID). The tube must be installed with the supplied inners andsleeves attached to prevent a leak.
When the tube is cut, its cut point has a smaller inner diameter. Use a file etc. to expand the inner diameterof the cut point. To remove cut-dust remaining inside of the tube, blow compressed air into the tube before
connecting it to the detector.
Some sample gases have highly adsorptive or corrosive property. Select the tube material taking into
account of these precautions.
Be careful that the flow rate introduced to the detector is in the range of 0.8 - 2 L/min (the maximum
pressure inside the flow path and sensor parts is 10.13 kPa <gauge pressure>).

WARNING The detector is designed to draw gases around it under the atmospheric pressure.
Be sure that excessive pressure is not applied to the sampling inlet and outlet (GAS IN, GAS OUT) of
the detector.
 Detected gases must be exhausted from the detected gas exhausting outlet (GAS OUT) to which an
exhaust tube is connected, to a point regarded as a safe place.

CAUTION The longer the tube of the GAS IN is, the longer it takes for a gas to reach the detector. Becausesome gases have a highly adsorptive property for the tube, resulting in a slow response and a lower
reading than the actual value, the length of the GAS IN tube must be minimized.
 When the humidity in the sampling point is high, condensation may be formed inside of the tube.
Make sure to avoid condensation when using a gas which is dissolved into water and corrodes
contacted materials, such as a strong acid gas, because it is undetectable and furthermore may
corrode internal parts. Also avoid an excessive U-shaped or V-shaped tube piping.
 Determine the inlet for the sample gas, considering the air flow of the sample gas line and the gas
generating process.
 To remove dust, do not forget to attach a dust filter in the middle of the tube.
 You need to decide the length and material of the tube. Please contact RIKEN KEIKI for more
information.

- 22 -

5 How to Operate

5-1. Preparation for start-up

5

How to Operate
5-1. Preparation for start-up
Before supplying power, read and understand the following precautions. Ignoring these precautions may
cause an electric shock or damage the detector.
 Connect the detector to a grounding circuit.
 Check that the wiring is connected to external device properly.
 Check that the power supply voltage is compliant with the specifications.
 Because the external contact may be activated during the adjustment, take measures to prevent anactivated contact from having influences on external device.
 Check that there is no clogging or leak in the connected tube. (If the connected tube is clogged, pressure isapplied to the sensor, causing errors and malfunctions.)
 Check that the filter is attached properly. (The filter is specified based on the gas to be detected.)

5-2. Basic operating procedures
Normally, the detection mode is activated after the power is turned on.

LED

MENU/ESC(long pressing)

MENU/ESC(long pressing)≪Maintenance Mode≫(User)
LED

LED

≪Maintenance Mode≫(Regular maintenance)
LED

LED

- 23 -

5 How to Operate

5-3. How to start the detector

WARNING
When the detector enters other mode from the detection mode while an alarm is activated, the alarm isreset.

5-3. How to start the detectorBefore supplying power (24 VDC) to the detector, check that the detector is installed properly.
Supply power (24 VDC) to the detector (turn on the detector).
After the detector completes the start-up, it enters the detection mode swiftly.
Perform the adjustment of an external pump etc. so that the flow rate introduced to the detector is in
the range of 0.8～2 L/min (the maximum pressure inside the flow path and sensor parts is 10.13 kPa<gauge pressure>).

CAUTION Do not turn off the detector during the initial clear. The detector is reading the internal memory during
the initial clear.
 If the detector is installed newly or the new sensor is replaced, the sensor must be warmed up for a
specified period which is determined depending on the type of the sensor after the detector is started.
 After the warm-up is completed, perform a gas calibration.

NOTE<<Start-up Operation Procedures>> (approximately 25 seconds for system check of the detector and alarmdeactivation)
Power on → Initial clear (approximately 25 seconds) → Detection modeLED

- 24 -

5 How to Operate

5-4. Modes

5-4. Modes
Details on each mode are provided as follows.

CAUTION Do not change the settings if not necessary. Changing the settings without understanding thespecifications may cause malfunctions.

Mode
Detection
Mode
MaintenanceMode(User)

Item-

LED display
Gas
concentration

Details

ROM/SUM Display

1-0

Zero Adjustment
Setting Display
Switch to the regular
maintenance mode

1-1
1-2

Display the program version and others.
This is not typically used by the user.
Perform the zero adjustment.
Display various setting values.

1-3

Switch to the regular maintenance mode.

Test Mode

2-0

Perform various tests.
2-0.0 Gas Test
2-0.1 Alarm Test
2-0.2 Fault Test
2-0.3 LED Test
2-0.4 Memory Test

Zero Adjustment
Span Adjustment
Zero/Span Initialization

2-1
2-2
2-3

Environmental Setting

2-4

Normal state

Perform the zero adjustment.
Perform the span adjustment.
Initialize zero/span values.
Used for various environmental settings.
2-4.0 Sensor power supply ON/OFF
2-4.1 INHIBIT Setting
2-4.2 Alarm Setpoint Setting
2-4.3 Alarm Delay Time Setting
2-4.4 Alarm Pattern Setting
2-4.5 Zero Suppression Pattern Setting
2-4.6 Zero Suppression Value Setting
2-4.7 Alarm Contact Specification Setting
2-4.8 Energized/De-energized Contact
Setting
2-4.9 Zero Follower Selection
2-4.A Maintenance Mode External Output
Setting
2-4.B External Output Setting
2-4.C Alarm Test External Output Setting
2-4.D Sensor Temperature Compensation
Coefficient Setting
2-4.E Password Setting
2-4.F Sensor Fault Alarm Pattern Setting
2-4.H Sensor Voltage Standardize

Maintenance
Mode(Regularmaintenance)

Adjustment

Display

2-5

Switch to factory mode
Switch to user mode

2-6
2-7

2-4.I Sensor Output Record
Display various electrical settings.
This is not typically used by the user.
Not used
Returns to the user mode.

- 25 -

5 How to Operate

5-5. Maintenance mode(User)

5-5. Maintenance mode(User)WARNING
After the adjustment is completed, never fail to press MENU/ESC key to return to the detection mode.
(If the detector remains in the user mode, it automatically returns to the detection mode in ten hours.)

LED⇒ Page 26

Show Various Settings⇒ Page 27

Switch to the regular
maintenance mode.

- 26 -

5 How to Operate

5-5. Maintenance mode(User)<Zero Adjustment "1-1">This is used to perform the zero adjustment.
LED

NOTE

 If the zero calibration failed since the zero point was significantly fluctuated from around zero, it returns to
1-1 after FAIL rather than PASS is displayed. In this case, the zero adjustment has not been completed.

- 27 -

5 How to Operate

5-6. How to exit

<Setting Display "1-2">
Display various setting values.
LED

Press SET key.

6.0
AL.:

The contact is activated
due to the gas alarm.
FAU.: The contact is activated
due to the fault alarm.
A.orF.: The contact is activated
due to the gas alarm or
the fault alarm.

5-6. How to exit
To turn off the detector, turn off the power supply (24 VDC) to the detector.

WARNING When the detector is turned off, an alarm may be activated on the upper (central) system.
 Before turning off the detector, INHIBIT (point skip) on the upper (central) system must be activated.
Decide whether power can be turned off by checking the operation of the devices connected to theexternal output or external contact output terminal of the detector.
 If the alarm contact is energized (option), it is activated when the detector is turned "OFF".

- 28 -

6 Operations and Functions

6-1. Gas alarm activation

6

Operations and Functions
6-1. Gas alarm activation
Gas alarm: Activated when the concentration of detected gas reaches or exceeds the alarm setpoint value.
<<Auto-Reset>>

NOTE
The alarm setpoint is factory-set. Although the alarm delay time (standard: 2 seconds) works in the detector toprevent a false activation, it can be cancelled if not needed.

<Display Operation>
Gas Concentration Display
In case of over the detection range (Over Scale), "∩∩∩∩" is displayed on the LED.
Power Indicator Lamp (POWER: Green)
During operation, this lights up continuously.
Alarm Indicator Lamp (ALM: Red)
It lights up when the alarm setpoint value is reached to or exceeded.

<Contact Activation>
The contact is activated when the gas concentration reaches or exceeds the alarm setpoint value. (onlywhen the alarm is used)
The contact activation is reset automatically when the gas concentration drops below the alarm setpointvalue.

Concentration

Alarm setpoint

0

Time

Alarm lamp (ALM)
Alarm contact (terminal plate 4, 5)

Alarm delay time (2 seconds)- 29 -

6 Operations and Functions

6-2. Fault alarm activation<Response to Gas Alarm>
A gas concentration value exceeds the alarm setpoint
When a gas alarm is triggered, take actions in accordance with your management rules of gas alarm.
Normally, take the following actions.
 Check the reading of the detector.

NOTE
If a gas leak is momentary, the reading may already have dropped when checking it. In addition, when thealarm is triggered by noise or other incidental conditions other than a gas, the reading may have already
dropped.
 Based on your management rules of gas alarm, no one can be allowed to access the monitored zone toensure safety.
 If the gas concentration display continues to be displayed, close the main valve of the gas, and then checkthat the gas concentration reading dropped.
 Equipped with a protective gear to avoid dangers caused by possibly remaining gases, before accessing
the gas leak point, and then check that gases remain by using a portable gas detector.
 Determine that the point is free from dangers, and take actions to fix the gas leak.

6-2. Fault alarm activation
A fault alarm is triggered when the detector detects abnormalities. After a fault alarm is triggered, the fault
lamp (yellow) lights up and an error message is displayed on the LED. Determine the causes and takeappropriate actions.
After the detector is successfully returned from the fault, it restarts with the process normally performed rightafter it is turned on (initial clear).
If the detector has problems and is repeatedly malfunctioning, contact our overseas sales department or
local representative immediately.

<Display Operation>
Fault Detail Display
Display a message indicating the fault detail.
Fault Lamp (FAULT: Yellow)
This lights up when a failure occurs.

NOTE
For information on malfunctions (error messages), see "9. Troubleshooting".

- 30 -

6 Operations and Functions

6-3. External output operation

6-3. External output operation
Signal Transmission System
Transmission Path
Transmission DistanceConnection Load ResistanceModePower Off1
2
Initial Clear

3
4
5
6
7

Detection Mode(No alarm)
Detection Mode(Gas alarm)
Detection Mode
(Full scale over)Fault Alarm
INHIBIT

8

Alarm Test

9

Maintenance Mode(User)
Maintenance Mode(Regular
Maintenance)

Electric current transmission (non-isolated) 4 – 20 mA
CVVS
CVVS 1.25 mm2: Maximum 1.25 km
CVVS 2.0 mm2: Maximum 2.0 km
Below 300 Ω
4 - 20 mA(output value)
0 mA
Depending on the setting of the section 9
2.5 mA setting: 2.5 mA
4 mA, HOLD, 4 - 20 mA setting: 4 mA
4 - 20 mA (concentration output)
4 - 20 mA (concentration output)
Less than 22mA:lenear output (concentration output)
Exceed 22mA:22mA(Fixed)
0.5 mA (Fixed)
Depending on the setting of the section 9
2.5 mA setting: 2.5 mA
4 mA, HOLD, 4 - 20 mA setting: 4 mA
Output ON setting: 4 - 20 mA (concentration output)
Output OFF setting: 4 mA
2.5 mA setting: 2.5 mA
4 mA setting: 4 mA
HOLD setting: The previous value retained
4-20 mA setting: 4 - 20 mA (concentration output)

Example of Gas Concentration and External Output
4 - 20 mA specification(Maintenance output: 2.5 mA setting)External output
22 mA
20 mA

Detection Mode
Maintenance Mode

4 mA
2.5 mA
Zero suppression
0

CAUTIONGas concentration
Full scale The 4 - 20 mA output is already adjusted. In case of over scale, an output will not exceed 22 mA.
 Output during INHIBIT or initial clear is based on 4 - 20 mA output setting in the maintenance mode.
In particular, when the detector is started or the specification is changed, be careful about 4-20 mA
output setting. Understand how the detector functions, and take actions, if necessary, so that thesignal receiver side can prepare to avoid false alarms.

- 31 -

6 Operations and Functions

6-4. Other functions

6-4. Other functions<Suppression Function>
The sensors used with the detector are influenced by environmental changes (temperature, humidity, andother characteristics) or interference gases (interference characteristics) in no small measure, which affects
the reading. Therefore, the reading might be fluctuated around zero even in a normal environment.
This function obscures influences by environmental changes and interference gases around zero that haveno meaning for your management rules of gas alarm. This function is used to hide (suppress) the fluctuationof the reading under the setting value, indicating zero.
<<Example>>
Suppression Disabled
A fluctuation around zero is displayed as the reading.

Suppression Enabled
A fluctuation under the setting value is hidden with zero.
(Zero suppression)

NOTE The suppression function is factory-set. The standard setting value is 6% FS.
 In the maintenance mode, this function is disabled and the fluctuation of the reading under the setting
value is displayed.

CAUTIONA reading under zero is suppressed with the 10% FS suppression.
A reading that is 10% FS or more under zero is displayed as "-0.0", which prevents an accurate gas
detection and needs the zero adjustment.

- 32 -

7 Maintenance7-1. Maintenance intervals and items

7

MaintenanceThis is an important instrument for the purpose of safety.
To maintain the performance of the detector and improve the reliability of safety, perform a regular
maintenance.

7-1. Maintenance intervals and items
 Daily maintenance: Perform maintenance before beginning to work.
 Monthly maintenance: Perform maintenance on the alarm circuit (alarm test) once a month.
 Regular maintenance: Perform maintenance once or more for every six months to maintain theperformance as a safety unit.
Maintenance
itemPower Supply
Check
Concentration
Display Check

Flow rate check
Filter check
Alarm Test
Span
Adjustment
Gas Alarm
Check

Maintenance content
Check that the power lamp lights up.
Check that the concentration display
value is zero. When the reading isincorrect, perform the zeroadjustment after ensuring that noother gases exist around it.
Check the flow rate to findabnormalities.
Check the dust filter for dust or
clogging.
Inspect the alarm circuit by using thealarm test function.
Perform the sensitivity calibration byusing the calibration gas.
Check the gas alarm by using thecalibration gas.

Daily
maintenance

Monthly
maintenanceRegularmaintenance











































<About Maintenance Services> We provide services on regular maintenance including span adjustment, adjustment and maintenance.
To make the calibration gas, dedicated tools, such as a gas cylinder of the specified concentration and gas
sampling bag must be used.
Our qualified service engineers have expertise and knowledge on the dedicated tools used for services,along with other products. To maintain the safety operation of the detector, please use our maintenanceservice.
 The followings are typical maintenance services. For more information, please contact our overseas sales
department or local representative.

- 33 -

7 Maintenance7-1. Maintenance intervals and items

Main Services
Power Supply
Check

:

Concentration
Display Check
Flow Rate Check:

Filter Check:

Alarm Test:

Span
Adjustment
Gas Alarm
Check:Cleaning andRepair of the
Detector(visualdiagnosis)
Detector
Operation
Check
Replacement ofConsumable
Parts

:

:

:

Checks the power supply voltage.
Verifies that the power lamp lights up.
(Verifies that relevant points can be identified on the system.)(When a UPS (uninterruptible power system) is used, checks the operation with the UPS(uninterruptible power system).)
Verifies that the concentration display value is zero by using the zero gas.
Performs the zero adjustment (AIR adjustment) if the reading is incorrect.
Checks the flow rate indicator to find abnormalities.
Checks the flow rate by using an external flow meter to verify the correctness of the flow rate
indicator on the gas detector. If the flow rate is incorrect, performs the flow rate adjustment.
Checks the dust filter for dust or clogging.
Replaces a dirty or clogged dust filter.
Inspects the alarm circuit by using the alarm test function.
• Checks the alarm lamps. (Check each activation of ALM.)• Checks the external alarm. (Checks the activation of the external alarm, such as a buzzer.)
Performs the sensitivity calibration by using the calibration gas.
Checks the gas alarm by using the calibration gas.
• Checks the alarm. (Checks the alarm activation when the alarm setpoint is reached.)• Checks the delay time. (Checks time to delay until the alarm is triggered.)• Checks the alarm lamps. (Check each activation of ALM.)• Checks the external alarm. (Check the activation of external alarms, such as a buzzer andreset signal.)
Checks dust or damage on surface, cover, or internal parts of the detector, clean and repair
such parts of the detector.
Replaces parts which are cracked or damaged.

:

Uses the keys to check the operation of functions and parameters.

:

Replaces consumable parts, such as a sensor, filter and pump.

- 34 -

7 Maintenance7-2. Maintenance mode (Regular maintenance)

7-2. Maintenance mode (Regular maintenance)
WARNING
After the adjustment is completed, never fail to press MENU/ESC key to return to the detection mode.
(If the detector remains in the maintenance mode, it automatically returns to the detection mode in ten
hours.)

Mode

Maintenance Mode
(Regularmaintenance)

Item

LED
display

Details

Test Mode

2-0

Perform various tests.
2-0.0 Gas Test
2-0.1 Alarm Test
2-0.2 Fault Test
2-0.3 LED Test
2-0.4 Memory Test

Zero Adjustment
Span Adjustment
Zero/Span
Initialization

2-1
2-2

Perform the zero adjustment.
Perform the span adjustment.

2-3

Initialize zero/span values.

Environmental
Setting

2-4

Used for various environmental settings.
2-4.0 Sensor power supply ON/OFF
2-4.1 INHIBIT Setting
2-4.2 Alarm Setpoint Setting
2-4.3 Alarm Delay Time Setting
2-4.4 Alarm Pattern Setting
2-4.5 Zero Suppression Pattern Setting
2-4.6 Zero Suppression Value Setting
2-4.7 Alarm Contact Specification Setting
2-4.8 Energized/De-energized Contact Setting
2-4.9 Zero Follower Selection
2-4.A Maintenance Mode External Output
Setting
2-4.B External Output Setting
2-4.C Alarm Test External Output Setting
2-4.D Sensor Temperature Compensation
Coefficient Setting
2-4.E Password Setting
2-4.F Sensor Fault Alarm Pattern Setting
2-4.H Sensor Voltage Standardize
Adjustment

2-4.I Sensor Output Record
Display various electrical settings.
This is not typically used by the user.

Display

2-5

Switch to factorymode
Switch to user
mode

2-6

Not used

2-7

Returns to the user mode.

- 35 -

7 Maintenance7-2. Maintenance mode (Regular maintenance)
LED

User ModeIn "1-3.", press SET key.

Then press SET key again
for three seconds.
Maintenance Mode
2-0. Test Mode
Perform various tests.

Test Mode=> P362-1. Zero Adjustment
Perform the zeroadjustment.

Zero Adjustment=> P422-2. Span Adjustment
Perform the span
adjustment.

Span
Adjustment=> P432-3. Zero/Span Initialization
Initialize the zero/span
adjustment after the sensor
is replaced.
2-4. Environmental Setting
Set various operations andfunctions.

Environmental
Setting=> P402-4.0 and 2-4.3 to 2-4.I arefactory-set. They are nottypically used by the user.

2-5. Various Electrical
Settings Display
Display various electricalsettings. This is not used by
the user.
2-6.
Enters the factory mode.
This is not used by the user.

2-7.
Returns to the user mode.

rET. is displayed.
Press SET key
again to return tothe user mode.

To 2-0. Test Mode
- 36 -

7 Maintenance7-2. Maintenance mode (Regular maintenance)<Test Mode "2-0">
LED

2-0
Press SET key.

2-0.0 Gas Test

Gas Test=> P372-0.1 Alarm Test

Alarm Test=> P372-0.2 Fault Test

Fault Test=> P382-0.3 LED Test

LED Test=> P382-0.4 Memory Test

Memory Test=> P39

To 2-0.0

WARNING Before starting the alarm test (transmission test), provide a notification to the related sections so thatthey can prepare for false abnormalities (external output signals and alarm contact). After the test iscompleted, never fail to press MENU/ESC key to return to the detection mode. (If the detector
remains in the alarm test mode, it automatically returns to the detection mode in ten hours.)
 In the alarm test mode, the gas concentration equal to the reading is output even in the maintenancemode depending on the setting. Take actions, if necessary, so that the signal receiver side canprepare to avoid false alarms.

- 37 -

7 Maintenance7-2. Maintenance mode (Regular maintenance)<Gas Test "2-0.0">
LED

2-0.0
Press SET key.

Introduce the test gas andperform the gas test.

Stop introducing the test gas. Whenthe reading drops, press MENU/ESC
key to cancel the test and to go backto the original state.
To 2-0.0

WARNING
Because the contact and gas concentration output can be activated by a gas test even in themaintenance mode depending on setting, be careful to perform the test.

<Alarm Test "2-0.1">
LED

2-0.1
Press SET key.

Alarm Test ON/OFF(The used contact setting is an alarm,an alarm or a fault)
Select either ON/OFF, and then press
SET key.
Perform the gas alarm test byincreasing or decreasing the readingwith  or  key.
Press MENU/ESC key to cancel thetest and to go back to the originalstate.

To 2-0.1

WARNING
Because the contact and gas concentration output can be activated by an alarm test even in themaintenance mode depending on setting, be careful to perform the test.

- 38 -

7 Maintenance7-2. Maintenance mode (Regular maintenance)<Fault Test "2-0.2">
LED

2-0.2
Press SET key.

Fault Test ON/OFF
Select either ON/OFF.
Switch ON and press SET key toactivate the fault alarm.
Return to OFF and press SET key todeactivate the fault alarm.
(Pressing MENU/ESC key alsoenables to cancel this menu and to go
back to the original state.)

WARNING
Because the contact and gas concentration output can be activated by a fault test even in themaintenance mode depending on setting, be careful to perform the test.

<LED Test "2-0.3">
LED

2-0.3
Press SET key.

LED Test ON/OFF
Select either ON/OFF.
Switch ON and press SET key to turnon the LED (POWER, ALM, FAULT)
and to display the gas concentrationof 8.8.8.8..
Return to OFF and press SET key todeactivate this menu.
(Pressing MENU/ESC key alsoenables to cancel this menu and to go
back to the original state.)- 39 -

7 Maintenance7-2. Maintenance mode (Regular maintenance)<Memory Test "2-0.4">
LED

2-0.4
Press SET key.

When StA. is displayed, press SET
key again.

When CAL. is displayed, the memory
diagnosis is performed.

When memory is correct as a result of
the diagnosis, PASS is displayed.
Press SET key to go back to theoriginal state.

To 2-0.4

NOTE
When abnormalities are found in memory as a result of the diagnosis, PASS is not displayed. F-RA isdisplayed for the RAM fault, and F-RO is displayed for the ROM fault. For both the RAM fault and ROM fault,
F-RA and F-RO are displayed alternately.

- 40 -

7 Maintenance7-2. Maintenance mode (Regular maintenance)<Environmental Setting "2-4">
Set various operations and functions in the environmental setting.
LED<<Environmental Setting 1>>
2-4. Environmental Setting
Press SET key.

2-4.0
This is factory-set and not
typically used by the user.

2-4.1 INHIBIT Setting
Set INHIBIT.
Select either ON/OFF, and thenpress SET key to confirm theselection.
When ON is selected, in thedetection mode InHI. and 0.0(gas concentration value) aredisplayed on the LCD
alternately. As a result, an alarm
is not triggered to external
device.
Alarm Setpoint Setting=> P402-4.2 Alarm Setpoint Setting
Set the alarm setpoint.

2-4.3 to 2-4.I
They are factory-set and not
typically used by the user.

2-4.3～2-4.I
To 2-4.0<Alarm Setpoint Setting "2-4.2">
LED

2-4.2
Press SET key.

Alarm Setpoint Setting
Select the number by pressing
 or  key, and then press
SET key to confirm the value.
(Press MENU/ESC key to go
back to the original state.)

Return to 2-4.2.

NOTE
It can not be set to a value exceeding 60% of the detection range.

- 41 -

7 Maintenance7-3. Gas calibration method

7-3. Gas calibration method(1) Pipe is attached as shown by the figure below.
With type of calibration gas, pipe configuration is targeted by "pushing type" or "suction type".
When calibrate with solvent gas, only “suction type” and Teflon tube can be allowed. (Length of gas
sampling bag and gas calibration adapter tube is within 30cm.)(2) Perform a gas calibration in each mode (zero adjustment mode and span adjustment mode) using thecalibration gas.
 Zero adjustment gas
 Span adjustment gas (collected in a gas sampling bag) Gas sampling bags
*Use a tedlar bag when make gas from solvent to prevent adsorption.
Pushing type (Calibration gas:gas )<<SD-1DRI>>

Flow meter OUT

Exhaust air

Pump

Gas
samplingbag

Gas calibration adapter

P

IN↑

Needle valve

Sunction type（Calibration：gas or solvent gas）

《SD-1DRI》

Teflon tube
(within30cm)

Gas
samplingbag

Pump
Exhaust air

IN→

Needle valve→
OUT- 42 -

Flow meter7 Maintenance7-3. Gas calibration method<Zero Adjustment "2-1">
This is used to perform the zero adjustment.

WARNING
When the zero adjustment is performed in the atmosphere, check the atmosphere for freshness before
beginning the adjustment. If other gases exist, the adjustment cannot be performed properly, thus
leading to dangers when the gas leaks.

NOTE Before starting the zero adjustment, provide the detector with the zero adjustment gas and wait until theindicator is stabilized.
LED

2-1
Press SET key.

Current Concentration Value Display
Press SET key to perform the zeroadjustment.

Under Zero Adjustment (CAL. is displayed)
Wait for a while until the adjustment iscompleted.

Zero Adjustment Completed
It automatically returns to 2-1 after
PASS is displayed.

Return to 2-1.
* If the zero adjustment failed, it
automatically returns to 2-1 after
FAIL is displayed.
Return to 2-1.

NOTE

 If the zero calibration failed since the zero point was significantly fluctuated from around zero, it returns to
2-1 after FAIL rather than PASS is displayed. In this case, the zero adjustment has not been completed.

- 43 -

7 Maintenance7-3. Gas calibration method<Span Adjustment "2-2">This is used to perform the span adjustment.

CAUTION Before starting the span adjustment, provide the detector with the span adjustment gas (adequate 1.6
times thicker gas than alarm setpoint value or 40% F.S.)and wait until the indicator is stabilized.

NOTE

 An exclusive jig is necessary to perform span adjustment. We recommend that you ask our local sales
office nearest you.
LED

2-2
Press SET key.

Gas Introduction
Introduce a gas, and then press SET key
when the reading is stabilized.
* In case of less than 10% F.S., thiscannot be set.

25.0

Span Adjustment
Because the reading will be fixed, selectthe introduced gas concentration bypressing  or  key.
Select the number, and then press SET
key.

Span Adjustment Completed
It automatically returns to 2-2 after PASS
is displayed.

Return to 2-2.
* If the span adjustment failed, it
automatically returns to 2-2 after FAIL
is displayed.
Return to 2-2.

NOTE

 If the span adjustment failed since the reading was significantly fluctuated from the introduced gas
concentration, it returns to 2-2 after FAIL rather than PASS is displayed . In this case, the span adjustment
has not been completed.
Check if the correct concentration span adjustment gas has been provided and check the gas adjustment
tool for a gas leak. If there are mistakes, perform the span adjustment again.
If the span adjustment cannot be performed even when there is no mistake or after the correction, the gas
sensor life has expired. After turning off the power supply, please contact our overseas sales department
or local representatives.

- 44 -

7 Maintenance7-4. Parts replacement

7-4. Parts replacement<Sensor Replacement>Gas sensor replacement is according to the following procedures.
(1) Turn off the power supply (24V) to the detector.
(2) After loosened set screw by hex wrench (nominal size 2),remove sensor guard by hex wrench (nominal
size 6).
(3) Remove the sensor. Pinch top of sensor (sintered metal portion) by using finger, and pull out it.
(4) Mount a new sensor. There are five pins for sensor, but a pin is longer than the others to show thereference, and equip detection unit with sensor .When put on the sensor, do NOT scratch mating portionof side of the sensor and adapter inside.
(5) After replacing a sensor, put on a sensor guard and set screw firmly.
(6) After sensor replacement, turn on the power and warm – up, then do the zero - point adjustment andspan adjustment by [7-3．Gas calibration method].
After the fixed, sets screw istightened in hex wrench (nominal
size 2)

SensorSensorHex wrench

Sensorguard
Sensorguard

Turning to
the main body front

When put on the sensor, do NOT
scratch mating portion of side of
the sensor and adapter inside.

NOTE
The gas calibration using the standard gas is required after the sensor is replaced. Please request it to ouroverseas sales department or local representatives.

WARNING Do NOT exchange any parts while turn on electricity. It may happen fire.
 Turn off the power supply, and then replace parts.

- 45 -

7 Maintenance7-4. Parts replacement<Replacement of Regular Replacement Parts>
List of recommended regular replacement parts
No.

Item

Maintenanceintervals

Replacement
intervals (year)

Quantity(pieces/unit)

1

Guard assembly

6 months

3 - 8 years

1

2

Aspirator cap

6 months

3 - 8 years

1※ After replacements having need of operation check by professional service engineers.
To maintain the safety operation of the detector, please use our maintenance service.
Request RIKEN KEIKI for it.

NOTE

 The above replacement intervals are recommendation only. The intervals may change depending on theoperating conditions. These intervals do not mean the warranty periods either. The result of the regular
maintenance may determine when to replace the parts.

- 46 -

8 Storage, Relocation and Disposal

8-1. Procedures to store the detector or leave it for a long time

8

Storage, Relocation and
Disposal
8-1. Procedures to store the detector or leave it for along time
The detector must be stored under the following environmental conditions.
 In a dark place under the normal temperature and humidity away from direct sunlight In a place where gases, solvents or vapors are not present

8-2. Procedures to relocate the detector or use it again
When the detector is relocated, select a new place in accordance with "4-2. Precautions for installation
points" and "4-4. How to install".
For information on wiring, see "4-6. How to wire". The unpowered time must be minimized when thedetector is relocated.

CAUTION When using a relocated or stopped/stored detector again, do not forget to perform a gas calibration.
For information on readjustment including a gas calibration, please contact our overseas sales
department or local representatives.

8-3. Disposal of products
When the detector is disposed of, it must be treated properly as an industrial waste in accordance with thelocal regulations.

- 47 -

9 Troubleshooting

9 Troubleshooting

9

Troubleshooting
The troubleshooting does not explain the causes of all the malfunctions which occur on the detector. This
simply helps to find the causes of malfunctions which frequently occur. If the detector shows a symptom
which is not explained in this manual, or still has malfunctions even though remedial actions are taken,
please contact our overseas sales department or local representatives.

<Abnormalities on Unit>
Symptom/Display

The power
cannot be turnedon.

Abnormaloperations

Sensorabnormalities
E-1

Systemabnormalities
E-9

FAULT

-

-





Causes
The wiring is not correct.
The terminal plate isremoved.

Actions
Connect the wiring properly.
Connect the terminal plate properly.

Abnormalities/momentary
blackout of power supply
systemProvide the rated voltage.
Check the UPS, power supply line filter andinsulation transformer, and then take additional
measures.

Cable abnormalities(open circuit/not
connected/short circuit)

Check the wiring of detector and related devices
around it.

Disturbances by sudden
surge noise, etc.

Turn off and restart the detector.
If such a symptom is observed frequently, takeappropriate measures to eliminate the noise.

The sensor is notconnected or improperly
connected.
Zero drift caused byenvironmental changes or
aging deterioration is outof the range of zero
follower.
Faults of the sensor
The rated voltage is not
supplied to the detector.
Abnormalities of ROM,
RAM, or EEPROM insideof the detector- 48 -

Check if the sensor cable is securely fastened tothe terminal plate.
Perform the zero adjustment. If the symptom
persists after the zero adjustment, replace thesensor with a new one.
Replace the sensor with a new one.
Check the power supply, and supply the rated
voltage.
Please contact our overseas sales department
or local representatives.

9 Troubleshooting

9 Troubleshooting<Abnormalities of Readings>
Symptoms

The reading rises(drops) and it remainsso.

CausesDrifting of sensor
outputPresence ofinterference gas
Slow leakEnvironmental
changes
Presence ofinterference gas

A gas alarm is triggered
despite of no gas leakand no otherabnormalities at thedetection point.

Slow response

Sensitivity calibration
impossible

Disturbance by
noise

Sudden change inthe environment

Clogged dust filter
Bended, clogged, or
leaked suction tube
or exhaust tube
Condensation isformed inside thesuction tube.
Deteriorated sensor
sensitivity
Improper calibration
gas concentration
Deteriorated sensor
sensitivity

Actions
Perform the zero adjustment.
Interference gas test including solvents are identified,and be treated properly.
A very small amount of the gas to be detected may beleaking (slow leak). Because ignoring it may cause
dangers, take a remedial measure, i.e., taking actions thesame as those for the gas alarm.
Perform the zero adjustment (AIR adjustment).
Interference gas test including solvents are identified,and be treated properly.
Turn off and restart the detector.
If such a symptom is observed frequently, takeappropriate measures to eliminate the noise.
When the environment (temperature, etc.) changes
suddenly, the detector cannot adjust to it and is affectedby it.
In some cases, the detector triggers an indication alarm.
Because the detector cannot be used under sudden andfrequent environmental changes, any preventive actions
should be taken to eliminate them by the user.
Replace the dust filter.
Fix the defective parts.

Fix the defective parts.

Replace the sensor with a new one.
Use the proper calibration gas.
Replace the sensor with a new one.

- 49 -

10 Product Specifications

10-1. List of specifications

10

Product Specifications
10-1. List of specifications<ATEX/IECEx Specifications>
Model
Detection principle
Detection gas
Concentration display
Detection range
Resolution
Detection method
Suction flow
Alarm setpoints
Power display
External output
Indicate accuracy(under an identical condition)
Response time
(under an identical condition)
Gas alarm typeGas alarm display
Gas alarm patternalarm・Self diagnosis
alarm display
alarm pattern
Alarm contact

SD-1DRI
Non-dispersive infrared absorption method
Combustible gas
LED(4digits・7segments)
Depend on detection gas
Depend on detection gas
Suction method(pour into by external unit)
1.0±0.1L/min
Depend on detection gas
POWER lamp lighting(green)
Gas concentration signal/Alarm contact(Gas alarm or Fault alarm or Gas・Fault common alarm)
Within ±5%FS(Repeatability：Within ±2%FS)
Within 60sec(T90)Single alarm(H)ALM lamp lighting(red)Auto-recover
System failure/Sensor failure
FAULT lamp lighting(yellow)/content display
Auto-recoverNo-voltage contact 1a・Non-exciting at normal(exciting at alarm) or
exciting at normal(non-exciting at alarm)
Contact capacity
30VDC・0.5A(resistive load)
Transmission scheme
Three-wire analog transmission(in common with power supply<power supply, signal, common>)Transmission specification
4 - 20mADC(linear・load resistance under 300Ω)Transmission cable
CVVS 1.25mm2 or 2.0mm2 - 3-core(when the contact is not used)
CVVS 1.25mm2 or 2.0mm2 - 5-core(when the contact is used)
Transmission distance
1.25km or less in case of CVVS 1.25mm2
2.0km or less in case of CVVS 2.0mm2
Functions
Alarm delay/suppression/zero follower
Power supply
24VDC±10%Power consumption
MAX.2W
Cabling port
Adapter A<NPT1/2> or adapter B<NPT3/4> or
Pressure proof packing gland <G3/4> (Compatible cables φ9.6 - 13.0mm in outer diameter)
Piping port
Rc1/8(with BS half union<for Cu pipe> or SUS half union<for SUS pipe> or
PP half union<for PTFE pipe> for O.Dφ6-1t)
Initial clear
Approx.25sec
Operating temperature*
Depend on detection gas(non-rapidly-vary)
Operating humidity
Below 95%RH(non-condensing)
Structure
Wall mounting type
Explosion protected construction
Flame proof structure
Explosion-proof class
Ⅱ2 G Ex db ⅡC T6 Gb(ATEX) / Ex db ⅡC T6 Gb(IECEx)
Dimension
Approx.148(W)×177(H)×88(D)mm(projection portions excluded)
WeightApprox.2.2kg
Color
Munsell 7.5BG5/2* The ambient temperature range which maintain a capability of explosion proof of the label on the detector is -20～+60℃. However,
the available operating temperature range is different depending on detectable gas (P 52).

- 50 -

10 Product Specifications

10-1. List of specifications

Outline Drawings

Adapter(NPT 1/2 )Aspirator cap- 51 -

10 Product Specifications

10-1. List of specifications<Japan Ex Specifications>
Model
Detection principle
Detection gas
Concentration display
Detection range
Resolution
Detection method
Suction flow
Alarm setpoints
Power display
External output
Alarm accuracy(under an identical condition)
Alarm-delay time
(under an identical condition)
Gas alarm typeGas alarm display
Gas alarm patternFault alarm・Self diagnosis
Fault alarm display
Fault alarm pattern
Alarm contact

SD-1DRI
Non-dispersive infrared absorption method
Combustible gas
LED(4digits・7segments)
Depend on detection gas
Depend on detection gas
Suction method(pour into by external unit)
1.0±0.1L/min
Depend on detection gas
POWER lamp lighting(green)
Gas concentration signal/Alarm contact(Gas alarm or Fault alarm or Gas・Fault common alarm)
Within ±25% to the alarm setpoint value

Within 30sec(when introducing 1.6 times thicker gas than alarm setpoint value)(without piping delay time)Single alarm(H)ALM lamp lighting(red)Auto-recover
System failure/Sensor failure
FAULT lamp lighting(yellow)/content display
Auto-recoverNo-voltage contact 1a・Non-exciting at normal(exciting at alarm) or
exciting at normal(non-exciting at alarm)
Contact capacity
250VAC・0.5A/30VDC・0.5A(resistive load)
Transmission scheme
Three-wire analog transmission(in common with power supply<power supply, signal, common>)Transmission specification
4 - 20mADC(linear・load resistance under 300Ω)Transmission cable
CVVS 1.25mm2 or 2.0mm2 - 3-core(when the contact is not used)
CVVS 1.25mm2 or 2.0mm2 - 5-core(when the contact is used)
Transmission distance
1.25km or less in case of CVVS 1.25mm2
2.0km or less in case of CVVS 2.0mm2
Functions
Alarm delay/suppression/zero follower
Power supply
24VDC±10%Power consumption
MAX.2W
Cabling port
Pressure proof packing gland <G3/4> (Compatible cables φ9.6 - 13.0mm in outer diameter)
Piping port
Rc1/8(with BS half union<for Cu pipe> or SUS half union<for SUS pipe> or
PP half union<for PTFE pipe> for O.Dφ6-1t)
Initial clear
Approx.25sec
Operating temperature range*
Depend on detection gas(non-rapidly-vary)
Operating humidity range
Below 95%RH(non-condensing)
Structure
Wall mounting type
Explosion protected construction
Flame proof structure
Explosion-proof grade
Ex d ⅡC T6 X(Japan Ex)
Dimensions
Approx.148(W)×177(H)×88(D)mm(projection portions excluded)
WeightApprox.2.2kg
Color
Munsell 7.5BG5/2* The ambient temperature range which maintain a capability of explosion proof of the label on the detector is -20～+53℃. However,
the available operating temperature range is different depending on detectable gas (P 52).

- 52 -

10 Product Specifications

10-1. List of specifications

Outline Drawings

Aspirator cap

Cable gland (G3/4)- 53 -

10 Product Specifications

10-1. List of specifications＜Detectable gas list＞
Detectable gas

Gas code

LNG
1,2-Dichloroethane
1,3-Dioxolane
1-Butene
1-Hexene
AcetoneIsobutane
IsobutenIsopropyl alcohol
IsoPentane
EthaneEthanol
Ethylene
XyleneMethyl chloride
Ethyl Acetate
n-Butyl acetate
Propylene oxide
Cyclopentane

LNG
EDC
C3H6O2C4H8
1-C6H12C3H6O
i-C4H10i-C4H8IPA
i-C5H12
C2H6
C2H5OH
C2H4
C8H10
CH3CL
EtAC
C6H12O2PO
C5H10

Dichloromethane
Diethyl carbonate
Dimethyl carbonate
Tetrahydrofuran
City gas 13A
TolueneCarbon Dioxiden-Butanen-Hexane

CH2CL2
C5H10O3C3H6O3
THF
13A
C7H8
CO2
n-C4H10n-C6H14n- Heptane
Pentane1,3-Butadiene
PropanePropylene glycol ethyl ether acetate
BenzeneMethanen-C7H16n-C5H12C4H6C3H8PGMMEAc
C6H6
CH4Methanol
Methyl ethyl ketone

CH3OH
MEK

Measuring
range

Alarm
point

0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-5000 ppm
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-10000 ppm
0-100 %LEL
0-100 %LEL
0-5 vol%
0-10 vol%0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 %LEL
0-100 vol%0-100 %LEL
0-10000 ppm
0-100 %LEL

25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
1250
25.0
25.0
25.0
25.0
25.0
25.0
5000
25.0
25.0
1.25
2.5
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
2500
25.0

Operating temperature
Japan
ExportSpecification
Specification-20～53℃-20～60℃-10～53℃-10～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-10～53℃-10～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-10～50℃-10～50℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-10～53℃-10～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-10～53℃-10～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-10～50℃-10～50℃-20～53℃-20～60℃-20～53℃-20～60℃-10～50℃-10～50℃-20～53℃-20～60℃-20～53℃-20～60℃-20～53℃-20～60℃-10～50℃-10～50℃-20～53℃-20～60℃* Please contact our overseas sales department or local representative except gas mentioned above.

- 54 -

10 Product Specifications

10-2. Detection principle

10-2. Detection principle
Model SD-1DRI is based on NDIR (Non-Dispersive Infrared) and this structure is shown below.
The infrared beam emitted from the light source passes through the gas cell, and optical band pass filter
which can pass the absorption wave of measuring gas and attains gas cell is absorbed by the measuringgas when measuring gas is supplied into the gas cell and will decrease according to its concentration.
The variable amount of infrared ray is measured by the infrared sensor and it is displayed as gas
concentration.
Then, there is no sensitivity against gas which have the different absorption wave from the measuring gas.
Then there is no sensitivity against N2 and H2 etc which cannot absorb infrared. As compared with theconventional catalytic combustion method, there is no poisoning material to be absorbed and almost no
sensitivity drop on this detection principle.
The light source, gas cell, infrared sensor etc are housed in a flame arrestor to be an explosion (flame) proof
structure.

Reflective mirror

Flame arrester

InfraredGas cell
Detectable gas

Optical filter

Light source

Infrared sensor
Gas concentration
Analog output- 55 -

11 Definition of Terms

11 Definition of Terms

11

Definition of Terms
Non-dispersive
infrared type
Initial clear
Full scale%LEL
ppm
Calibration
Zero suppression
Alarm delay time
INHIBIT

This is a principle of the sensor installed in the detector head.
See "10-2. Detection principle" for details.
Output from the detector head fluctuates for a while after turning on the power.
This is a function to prevent triggering alarm during that time.
Maximum value of the detection range.
A unit which the lower explosive limit (LEL) of the combustible gas to be detected is
set to 100.
A concentration unit that means part per million of the combustible gas to be
detected.
Adjusts the readings to the calibration gas concentration value by using thecalibration gas.
A function to cut off the specific drifting that the sensor has.
A function which temporarily suspends activation to prevent a false alarm caused
by noise from its outside.
The gas detection function is temporarily suspended during maintenance, etc. ofthe detector.
This is also called "point skip", which has the same function.

- 56 -