Diffusion type Gas Detector
Model KD-12
Instruction Manual Keep this instruction manual where it is readily accessible.
 Thoroughly read this instruction manual before using the equipment so it can be usedsafely and correctly.
 This manual provides information concerning standard specifications. If the specificationsof your model are nonstandard, refer to the delivery specifications.

New Cosmos Electric Co., Ltd.
Instruction Manual No.
GAE-048-08
September 2022

 Nomenclature Replacement of Sensor Unit

See pages 4 to 6.

See pages 29 and 30.

 Wiring and Connecting
Methods

 Display and Operation in
Each ModeSee pages 11 to 15.

See page 18.

24 V
power
supplyIndicator

ShieldE.g., External
alarm

Ground terminals

 Maintenance Check andOperation Methods
See pages 20 to 28.

 Troubleshooting
See page 31.

Table of Contents
1.
2.
3.
4.

Introduction .................................................................................................................. 1
Precautions .................................................................................................................. 2Contents of Package ................................................................................................... 3
External Dimensions and Nomenclature ..................................................................... 4
4-1. Main Unit .................................................................................................................. 4
4-2. Display and Control Blocks ...................................................................................... 5
4-3. Terminal Block .......................................................................................................... 6
5.
Installation.................................................................................................................... 7
5-1. Installation Method ................................................................................................... 7
5-2. Examples of Installation Positions ......................................................................... 10
5-3. Mounting of Optional items ..................................................................................... 11
6.
Wiring Method............................................................................................................ 12
6-1. Wiring Work............................................................................................................ 12
6-2. Wiring and Connection........................................................................................... 13
7.
Precautions before Use ............................................................................................. 16
 In Case of Gas Leakage .................................................................................................. 16

8. Display at Start-up (Initial Delay) ................................................................................... 17
9. Display and Operation in Each Mode ............................................................................ 18
10. Trouble Alarm ............................................................................................................... 19
11. Maintenance Check and Operation Method ................................................................ 20
11-1. Daily Inspection and Periodical Inspection ............................................................ 20
11-2. Preparing Calibration Gas ..................................................................................... 21
11-2. Preparing Calibration Gas (Continued) ................................................................. 22
11-3. Calibration Method ................................................................................................. 23
 Maintenance Mode ........................................................................................................... 23
 Zero Adjustment ............................................................................................................... 24
 Span Rough Adjustment................................................................................................... 26
 Full-scale and Alarm Set Value Display ........................................................................... 27
 Test Mode ......................................................................................................................... 28

11-4. Replacement of Sensor Unit ................................................................................. 29
12. Troubleshooting ........................................................................................................... 31
13.
Specifications ............................................................................................................. 32
14. Markings of explosion-proof ..................................................................................... 33
15. Warranty ................................................................................................................... 34
16. Life Expectancy ........................................................................................................ 34
17. Detection principle ....................................................................................................... 35
18. Glossary ....................................................................................................................... 36

1. Introduction
 Thank you for purchasing the KD-12 Diffusion type Gas Detector.
 In order to ensure the correct and safe operation of this product, be sure to read thismanual before use.
 This product detects combustible gas, and CO2. The product detects gas leakage at an
early stage in industrial facilities (e.g., gas production plants and depots, chemical plants,
paint factories, and power plants), and outputs the gas concentration value in analog
signal form while displaying the gas concentration value.
If the gas concentration reaches a preset alarm level, the red ALARM indicator will flash
and turn ON an external contact output, thus helping to prevent disasters such as
explosion accidents and fires.
 Maintenance and inspection are indispensable to the reliable performance of the Gas
Detection/Alarm System. Be sure to perform the maintenance checks described in thismanual.

Explanation of Symbols
The following symbols are used to indicate and classify precautions in this manual.

DANGER

Indicates information that, if not heeded, is likely to result in death orserious injury.

WARNING

Indicates information that, if not heeded, could possibly result in death orserious injury.

CAUTION

Indicates information that, if not heeded, could result in minor injury, or
damage to the product.

MEMO

Indicates advice on handling the product.

12. Precautions
 Read this manual completely and be sure you understand the information provided herein
before attempting to use the product.
 Abide by all applicable laws and regulations when using this product.

WARNING Be sure to ground the product to prevent electric shocks.
 If there is a gas leak alarm, take the necessary measures in accordance with yourcompany's regulations.
 The cable entry device and blanking elements shall be of ATEX/UKEx/IECEx certified in typeof explosion protection flameproof enclosure ‘’db’’, suitable for the condition of use andcorrectly installed.
 Unused apertures shall be closed with suitable ATEX/UKEx/IECEx certified blanking
elements.
 Fastener type M5 x 16 shall have a yield stress factor of min. 450 N/mm2.

CAUTION All necessary work for the product including wiring and installation should be carried out by
suitably trained personnel in accordance with applicable code of practice.
 Inspection, maintenance and repair of the equipment should be carried out by suitablytrained personnel in accordance with applicable code of practice.
 Do not disassemble the product or modify
the construction or electric circuits of the product.
WARNING
Otherwise, the explosion-proof construction of the product may be adversely affected.
 Do not install the product in places or near places where silicone sealant or gas is used.
Otherwise, the performance of the product may be adversely affected.
 Be sure to provide a protective cover (optional) if the product is installed outdoors.
 Use the product in accordance with applicable laws and regulations.
 Hydrocarbon gas except the target gas might be detected, so consider the measurement
environment.

Special Condition for Safe Use If used in an ATEX hazardous area, an ATEX-certified cable gland must be used according
to EN IEC 60079-0:2018 and EN 60079-1:2014. (Not included)
 If used in an UKEx hazardous area, it must be used a suitably certified cable gland for UKEx
requirements. (Not included)
 If used in an IECEx hazardous area, an IECEx-certified cable gland must be used according
to IEC 60079-0:2017 Edition 7.0 and IEC 60079-1:2014 Edition 7.0. (Not included)
 Fasteners (M5x16 hexagonal head screws) shall have yield stress of at least 450 N/mm2.
 Cable entry requirements for cable gland:
Thread size………………………… G3/4 or PF3/4
Minimum depth of engagement …. 10.86mm
Minimum thread engagement…….. 6 threads

 The dimensions of a flameproof joint between the case and the case cover of the KD-12
flameproof housing must meet the minimum requirements specified in EN/IEC60079-1.
Please contact the manufacturer for inspection, repair or adjustment of the flameproof joint.
23. Contents of Package
 The product is provided with the following items. Make sure that none of these items is
missing.
 Although the product is packed and shipped with the utmost care, contact your New
Cosmos representative if there should be any damage or missing items.
Accessories

Optional items

Detector head
Accessory set
Two M5 screws: 2 pcs
M4 x 4 hexagon socket head screw:1pc

Protective cover (see note 2)
Horizontal type: KW-41A
Vertical type: KW-42A
PB-1 2B Pole Mounting Bracket (see note 2)
SK-1 Sensor Replacement Jig (see note 2)
GCP-09 Calibration Cap (see note 2)
Z-001K Gas Calibration Kit
2 bulb hand pump
Capillary for 2 bulb hand pump

Hexagon wrench (nominal dia. 4): 1 pc
Instruction Manual (see note 1)
MJ-1 Magnetic Stick: 1 pc

Note: 1. A Instruction Manual is provided for each order.
2. The optional items are for use only with KD-12.

WARNING Do not use the magnetic stick for any purposes other than the operation of this product.
 Keep any magnets away from the equipment except MJ-1 magnetic stick.
 Keep in mind that when the magnetic stick attracts magnetic objects, tools, iron pieces,
etc., your hands may become pinched and injured.
 Do not touch the magnet if you are allergic to metal, otherwise your skin may becomechapped or reddened.
 Generally speaking, magnets break easily and the corrosion of the magnet progresses
from the fracture location. Fragments of the magnet may also get in your eyes or injure
your skin.
 The components of the magnetic stick may melt into water. Do not drink water exposed tothe magnetic stick.
 Keep the magnetic stick away from electronic medical devices, such as cardiac
pacemakers, or the magnetic stick may obstruct the normal operation of the device.

CAUTION Keep the magnetic stick away from magnetic tapes, floppy disks, and prepaid cards.
Otherwise, they may become magnetized and the information that they hold may be lost.
 Keep the magnetic stick away from high-precision devices, such as personal computers
and watches. Otherwise, they may malfunction.

34. External Dimensions and Nomenclature
4-1.

Main Unit(Dimensions are in mm)

NumberName

Description(1)

Case cover

---

(2)

Case

---

(3)

Sensor unit

Incorporates a built-in gas sensor.

(4)

Earth terminal(external)

Used for grounding the frame.

(5)

Status lights(3 places)

Indicate the status of the unit:
power (green), alarm (red), and fault (yellow)(6)

Magnetic switches Insert the magnetic stick into each magnetic switch opening to(4 places)
operate.

(7)

Display

Displays the gas concentration, parameter value and status
message.

(8)

Cable entry

Thread size: G3/4 or PF3/4. Pitch=1.81mm.
Depth of engagement: 10.86mm.
Minimum engaged threads: 6 threads.
Applicable cable gland*1 must be provided by end user.

(9)

M5x16 Hexagonal
To secure the case cover.
head screws
Use 4mm hex key wrench (included).
(4 places)(10)

M4x4 Hexagonal
set screw(2 places)

To secure the cable gland (cable fitting) and the sensor unit. Use
2mm hex key wrench (not included).

*1: Cable gland should be ATEX/UKEx-certified according to EN IEC 60079-0:2018 for use in an
ATEX/UKEx hazardous area, and EN 60079-1:2014, and IECEx-certified according to IEC
60079-0:2017 Edition 7.0 and IEC 60079-1:2014 Edition 7.0 for use in an IECEx hazardous area.

4

4-2.

Display and Control Blocks

Magnetic Switches
Use the magnetic stick (MJ-1) to operate the magnetic switches.
Item

Component

Description/Function(1)[MODE] switch

Changes the operation mode or cancels the current
operation.

(2)[ENTER] switch

Confirms a setting or executes an operation.

(3)[UP] switch

Increases the parameter value.

(4)[DOWN] switch

Decreases the parameter value.

Item
(5)

Component

Description/Function
Displays gas concentration, parameter value and status
message.

Display

Status Lights
Item

Component

Description/Function(6)[POWER] light (green)

When lit, the unit is on.

(7)[ALARM] light (red)When lit, alarm notification.

(8)[TROUBLE] light (yellow)

When lit, fault (device error) detected.

5

4-3.

Terminal Block

24V(+) 1
GND

2

Signal 3
ZA

4

ZC

5

POWER －
4～20mA＋E
Clamp

Groundterminal

1
2
3
4
5

Lever

Sensorconnector
O-ringNumber
1

Name

Description

24 V (+)

Power supply voltage (positive)

GND

Power supply voltage (-) and analog signal(negative) common

3

Signal4- to 20-mA (+) analog signal

4

ZA

5

ZC

2

External contact
Ground terminal

Used to ground the frame.

65. Installation
5-1.

Installation Method

WARNING The cable entry device and blanking elements shall be of ATEX/UKEx/IECEx
certified in type of explosion protection flameproof enclosure ‘’db’’, suitable for thecondition of use and correctly installed.
 If used in an ATEX hazardous area, an ATEX-certified cable gland must be usedaccording to EN IEC 60079-0:2018 and EN 60079-1:2014. (Not included)
 If used in an UKEx hazardous area, it must be used a suitably certified cable glandfor UKEx requirements. (Not included)
 If used in an IECEx hazardous area, an IECEx-certified cable gland must be usedaccording to IEC 60079-0:2017 Edition 7.0 and IEC 60079-1:2014 Edition 7.0. (Notincluded) Unused apertures shall be closed with suitable ATEX/UKEx/IECEx certified
blanking elements.
 Fastener type M5 x 16 shall have a yield stress factor of min. 450 N/mm2.
 The dimensions of flameproof joint between casing and casing cover of KD-12
flameproof housing are exceeding the minimum requirements stated
EN/IEC60079-1. Please contact the manufacturer for inspection, repair and/or
adjustments of this flameproof.
 Cable entry requirements for cable gland and sensor:- Cable gland- Sensor

Thread size: G3/4 or PF3/4

Thread size: M27

Pitch: 1.81mm

Pitch: 1.5mm

Min. depth of engagement: 10.86mm

Min. depth of engagement: 8.25mm

Min. thread engagement: 6 threads

Min. thread engagement: 5.5 threads

 Securely tighten the hexagonal set screws to ensure that no movement of thecable gland is possible.
Hexagonal set screws (2 places)
Screw Specifications
Size: M4x4
Screw length for securing cable gland: 3, 4, 5 or 6 mm
Screw length for securing sensor unit: 3 or 4 mmMaterial: Stainless steel

Note: The head of each screw shall be flush with the surface of the fitting.

7

CAUTION
 Be careful not to damage the gas detector when installing it. Otherwise, theexplosion-proof performance of the gas detector will be lost.
 Do not install the product in the following places.
- Places where the ambient temperature exceeds the operating temperature range(10C to 50C).
- Places where condensation occurs.
- Places where water is directly sprayed.
- Places subject to corrosive gas.
- Places near to devices generating high frequency and magnetism.
- Places where any hydrocarbon gases other than the target gas exist.
 Install the gas detector in places where can be maintained and inspected with ease.
 Install the gas detector in places free from vibration.
 Install the gas detector in places free from sudden temperature changes.
 Keep the gas detector free from impacts.
 When installing the gas detector outdoors, be sure to install the protective cover(optional).
 The installing height of the gas detector has an important relation to the specificgravity of the target gas to be detected. Install the gas detector in accordance withrequired regulations.

 Installing Height
Type of gas
Gas heavier than air(Example. LPG)

Installing height
10 cm or less from the floor(Height to the sensor guard tip)

Gas as heavy as air(Example: carbon
monoxide)
Gas lighter than air(Example: methane andhydrogen)

75 to 150 cm from the floor(Height to the sensor guard tip)
Near the ceiling

8

Remarks
Keep a distance of approx. 7cm
from the sensor guard tip foreasy maintenance andinspection
Decide the height by considering
the specific gravity of the target
gas and mounting environment.
Decide the height by consideringscaffold, etc. for easy
maintenance.

 Mount the main unit to the wall with the M5 screws that are provided with the product. Be
sure to install the protective cover (optional) when mounting the main unit outdoors.
Mount the main unit with a 2B pole mounting bracket (optional) when mounting the main
unit to a 2B pole. Refer to 5-3 Mounting of Options for details of optional products.

(Dimensions are in mm)

 The casing cover of the gas detector needs be opened at the time of wiring. Therefore,
when installing the gas detector, provide sufficient space to enable the casing cover to beopened to at least 90°.

(Dimensions are in mm)

9

5-2.

Examples of Installation Positions

 Install the product in places where gas easily accumulates.

Places where gas easily accumulates.
Gas detector
Roof fan(Exhaust port)

Entrance(Suction port)

Entrances and windows(Suction and exhaust ports)

Gas detector
mounting
position

Side view

Plan view
Example of Installation Position

Partition
wall

Pipe
Valve

Detector

FlangeExample of Outdoor Installation Position

10

5-3.

Mounting of Optional items

 Protective Cover
(190)

(90)

(90)

(190)
M3 screw(1 place)M3 screw(1 place)
(190)

(190)

(Dimensions are in mm)

Horizontal Type (KW-41A)

Vertical Type (KW-42A)

CAUTION Secure the casing cover with M3 screws if strong winds are expected.

 2B Pole Mounting Bracket(Dimensions are in mm)

11

6. Wiring Method
6-1.

Wiring Work Be sure to provide explosion-proof wiring if the product is to be used in a hazardous area.

WARNING The cable entry device and blanking elements shall be of ATEX/UKEx/IECEx certified in
type of explosion protection flameproof enclosure ‘’db’’, suitable for the condition of use
and correctly installed.
 Unused apertures shall be closed with suitable ATEX/UKEx/IECEx certified blanking
elements.

CAUTIONAll necessary work for the product including wiring and installation should be carried out
by suitably trained personnel in accordance with applicable code of practice.

 Inspection, maintenance and repair of the equipment should be carried out by suitablytrained personnel in accordance with applicable code of practice.

Cable Work
 Use a shielded cable, such as CVV-S with a thickness of 1.25 to 2.00 mm2. Lay all cables
in protective tubes, such as metal conduits or carbon steel pipes, or other protective
structure, such as a concrete duct.
 When using the external contact function of the product, which requires a five-conductor
cable, make sure that the maximum diameter of the cable conductor is 1.25 mm2. Whenusing only the analog signal function, which requires a three-conductor cable, without theexternal contact function, make sure that the diameter of the cable conductor is 12.5 mm2
or 2.00 mm2.

12

6-2.

Wiring and Connection

WARNING Before opening the case cover of the gas detector, be sure to eliminate possible sourceof ignition. Disconnect the power supply to the detector and all devices connected to it(e.g. indicator unit and signal converter).
 Be sure to ground the product to prevent electric shocks.

 Use a conductor with a cross-sectional area of at least 4mm2 for external grounding.
Place a plain flat washer between the case and the terminal.

CAUTION Wire the connecting terminals correctly.
 Separate connection cables from power lines as far as possible.
When closing the casing cover, make sure that the power supply cord, harness, andO-ring are not caught by the casing cover.

Connecting Power Supply and Signal Wires Provide dedicated breakers, if needed, to lines that are connected to peripheral devices,such as indicator units and signal converters.
 Use a dedicated cable, such as CVV-S (with a thickness of 1.25 to 2.00 mm2).
 Make sure that the power supplied to the product is within the specified voltage range.
 Make sure that the load resistance of the signal line, including the resistance of the wire, is
300 ohm or less.

13

6-2.

Wiring and Connection (Continued)

MEMO If the main unit is grounded on the power supply side, do not connect a shielded cableto the ground terminal (E) in the gas detector, or otherwise two-point grounding will result.
Connection

Example with Power Supply Side Grounded
KD-12R24V
power
supplyCVVS cable

Indicator

ShieldNot grounded

Groundterminals

External alarm

Ground terminal on
power supply side
Grounded

System Configuration Example
Single detector connected
Multiple detectors monitored
to indicator unit
togetherDetector
Detector

KD-12

Indicator unit

KD-12
Security
management system

V2M

KD-12
S-500

GAS
VISION

KD-12
Comprehensive gas
detection/alarm system

KD-12
For details, refer to the Instruction Manual of each device.

14

6-2.

Wiring and Connection (Continued)

Typical Connection Procedure(1)

Prepare a power supply that can provide 24 V.
(Do not turn on the power supply before wiring the main unit.)(2)

Loosen the hexagon socket bolts on the four corners of the main unit using theprovided hexagon wrench with a nominal diameter of 4 mm, and open the casing
cover of the main unit.

(3)

Press the lever of the terminal block with a flat-blade screwdriver.

(4)

The clamp will open. Insert the lead wire.

(5)

Connect the positive side of the power supply to the 24 V+ terminal.

(6)

Connect the negative side of the power supply to the GND terminal.

(7)

The lead wire will be automatically secured when the screwdriver is lifted.

(8)

Check that the power supply cords are securely connected to the terminals. This
completes the power supply preparations.

(9)

Wire the analog signal and external contact terminals, if required.

(10) Tighten the hexagon socket bolts (tightening torque: 0.8-2.4 Nm) on the four cornersof the main unit and close the casing cover of the main unit.

CAUTION

When lowering the lever of the terminal block, be careful not to allow the flat-blade
screwdriver to slip off of the lever. Otherwise, the flat-blade screwdriver may damage thesensor unit code or circuit board.

When closing the casing cover, make sure that the power supply cord, harness, and O-ringare not caught by the casing cover.

15

7. Precautions before Use

CAUTION Before turning ON any of the devices (e.g., indicator unit, signal converter) connected tothe product, recheck that all of the connections are correct. Make sure that the gas
detector and indicator unit or signal converter, in particular, are connected properly.

 In Case of Gas Leakage

DANGER Without panicking, check that there is no fire around the product. Do not touch any
electric switches under any conditions. Sparks from turning electric switches ON or OFF
may cause ignition.

WARNING If there is a gas leak alarm, take the necessary measures specified by your company.
 If a gas leak occurs indoors, open the windows and doors to ventilate the room.
 Check the gas leakage location and promptly take the necessary measures.
Measure the gas concentration with a portable gas detector and confirm the safety
before entering the detection site.

16

8.

Display at Start-up (Initial Delay)

CAUTION Check that there is no gas around the product before starting the product.
 If the sensor output is not stable, the external contact point may operate after the initialdelay. Release the interlock of the external equipment if necessary.
 During the initial delay, the analog signal fixed at 4 mA will be output and the external
contact will not operate.

(1)

When the power supply is turned ON, all of the indicator lamps (green, red, and yellow
lamps) and the display block are lit.

(2)

While the indicator lamps (green, red, and yellow lamps) are lit, the following items will
be lit for approximately 1 second each.
Software version number (of the main unit)
Full scaleAlarm set value

ex) 【

】

ex) 【

】

ex) 【

】

(3)

Then the POWER indicator (green lamp) will be flashed for approximately 1 minute.

(4)

When the POWER indicator is lit, the start-up of the main unit is completed and themain unit will be in gas monitor mode.

MEMO

 The operation with the magnet stick is not available during the initial delay.
 The initial delay lasts approximately one minute after the power is turned on.
 The indicated condensation value may change rapidly during the initial delay, but it is not a
failure.
 If the sensor unit has not been used (energized) for a long period after shipped fromfactory, it may take some time for the sensor to stabilize. When the sensor unit is turned
on after a long unused period, an alarm may be generated even when no gas exists.
Therefore, deactivate the interlocks of the external devices before starting operation.
 More than one hour after turning on the detector, make the zero adjustment and span
adjustment.Refer to 11.3 Calibration Method for the adjustments.

17

9.

Display and Operation in Each Mode
In excess of alarm set value
At start-up(Initial delay)
Green lamp
flashes

Maintenance mode

Gas monitor
mode

Green
lamp is
ON

Red
lamp
flashes

Test mode

Gas monitor
mode

Red lamp
Green flashes
lamp isON

Test mode
Red lamp
flashes

Green lamp
is ON

Contents
of display
[

]

[

]

The valueaccording to gas
concentration isdisplayed.
The value
gradually
approaches
zero.

Gas
concentration isdisplayed.

Analogsignal4 to 20 mA

Fixed at 4 mA

Gas
concentration
value is output.

Test value is
outputGas
concentration
value isoutput.

Test value is
output.

Contact
operation

Does notoperate (OFF).

Operates (ON).

Operates (ON).

Does notoperate(OFF).

Does notoperate(OFF).

[Set
concentration]
A full-scale testfrom 10% to110% is possible.

18

[Gas
concentration]

Displayedalternately[Test value]

Displayedalternately

10.

Trouble Alarm

 The product has a self-inspection function, and the trouble alarm will operate if a problem
occurs.
 The product will inform the user of the problem details with the display shown in thefollowing table when the trouble alarm operates.
 When the trouble alarm is generated, the analog signal will be approximately 0.9 mA or
below.
Screendisplay

Troubleindicator

Problemdetails

Probable cause

RemedyYellow lamp
flashes

Power supply
voltage droperror

The power supply voltage
is low.

Check the power supply
voltage.

The sensor connector is
disconnected or thesensor wire has broken.
Yellow lamp
flashesSensorZero error
The sensor output is low.

Lamp isOFF

Lamp isOFF

Zero-point
adjustment
error

Span
adjustment
error

There is gas in theambient air.

The gas concentration
applied for adjustment iswrong.

Check that the sensor
and the sensor connector
are securely connected.
Make the zero point
adjustment with the gas
doesn't lie between air
around the equipment.

After checking theambient air, make thezero adjustment again.
After checking the typeand concentration of gas,
make a span adjustment
again.
If the type andconcentration of gas issuitable, make spanrough adjustment.

 If a screen other than the above is displayed, refer to the 12. Troubleshooting section. If
the product does not reset to normal operation after taking the measures shown in thetable or if the problem is not listed in the table, contact your local representative.
 If the product goes into any unintended mode during adjustment or setting, cease
operating the product and contact your local representative..

19

11.

Maintenance Check and Operation Method11-1. Daily Inspection and Periodical Inspection
 Daily inspections are conducted by the user, while periodical inspections are conductedby your local representative.
Frequency

At least
once a month

Check item

Contents of inspection
 The status of lamp (green POWER indicator)
is lit.
 The concentration display of the gas
concentration indicator.
 Clogging of sensor unit mesh.
 Corrosion of sensor unit mesh.
 Corrosion of the main unit.
 Corrosion of mounting screw.
If a failure is found, replace the parts.
 Install the calibration cap, apply calibrationgas (test gas), and check the operation.
Refer to the manual of the calibration tool kit(optional) for a detailed check method.

Visualinspection

Daily
inspection

At least once
every 2 or 3
monthsAlarm operation
check with realgas
 Calibration gas

Calibration cap

 Check that nothing interrupts the diffusion ofgas around the gas detector.

Conditionaround gas
detector
Periodical
inspection

At least
once a year

Consult your local representative.

 Use optional products to make actual gas inspections.

Periodical Inspections
In order to maintain the reliability of the gas detection/alarm system, it is extremely important
to conduct maintenance and inspections.
Moreover, it is necessary to use actual gas (combustible gas), to carefully conduct inspection
and calibration. It is highly recommended that you consider periodical inspections under amaintenance contract with your local representative.

20

11-2. Preparing Calibration Gas
 Calibration gas is used for actual gas inspection.
 The following example shows how to prepare 2.00 vol% (40%LEL) Methane as areference gas.
With a standard gas cylinder

2.00vol% Methane airbalance21

Standard gas cylinder

Gas bag11-2.

Preparing Calibration Gas (Continued)

With no calibration gas cylinder Use the Gas Calibration Kit (optional) and a pure gas cylinder of methane at 99
vol% or more, and dilute the methane with air to produce 2.00 vol% (40%LEL)
calibration gas.
Memo

The calibration gas can be used to check the alarm function. Check theconcentration using Gas Detector XP-3110 or a similar device before using thegas for calibration.
●

DANGER

Make sure that there are no flammables nearby when handling
flammable gas with a concentration over LEL (lower explosive
limit).
vinyl tube

(1) Drawing raw gas
Connect a gas bag to a methane 99vol% cylinder and draw a little
more than you actually need.
Bend back the hose and pinch with a pinch cock so the gas does
not leak from the bag.

pure gas cylinder(Keep it upright.)①(2) Drawing a fixed amount of raw gas
Connect a 20ml syringe to a gasbag and draw 20.0ml of raw gas.
(Draw a little more than you actually need then discharge theexcess.)gas bag with raw
gas

20ml of raw gas
syringepull(3) Transferring raw gas into a quantitative pump
Connect a syringe to the inlet of a quantitative pump then pull out
the pump’s piston. Raw gas in the syringe is sucked into the pump.
Remove the syringe and pull the piston all the way out (100ml).

②

syringe(4) Making diluted gas
Connect an empty gasbag to the outlet of the quantitative pumpthen push in the pump’s piston.

quantitativepump

Move the piston back and forth 9 times to add air in order to makediluted gas.

③
air

Memo

quantitativepump

If you take 20.0ml of raw gas and move the quantitativepump’s piston back and forth 10 times (a back-and-force
motion: 100ml),
20.0ml/(100ml×10)=0.0020
0.2vol% diluted gas is made.
Methane’s lower explosive limit (LEL) is 2.0vol%.
0.2/5.0×100=40.0
40%LEL diluted gas is made.

22

gas bag withdiluted gas④

11-3. Calibration Method
 Maintenance Mode

CAUTION While in maintenance mode, the external contact does not operate when theconcentration of gas reaches or exceeds the alarm set value. The product inmaintenance mode maintains the current status while the display shows [].
This mode is canceled by repeating the same operation(1 to 4), turning the product OFF,or waiting 8 hours.

(1)

While in gas monitor mode, press the MODE switch of the main unit first. Then press
the UP switch with the magnetic stick within approximately 2 seconds.

(2)

The main unit displays
first, followed by.
(The product is ready to work but nothing has been operated.)(3)

Press the UP or DOWN switch of the main unit with the magnetic stick and adjust thevalue to.

[][Gas concentration](4)

Press the ENTER switch of the main unit.

(5)

When the above items are displayed alternately, the product has been set tomaintenance mode.

(6)

Upon completion of this mode, the product will automatically return to gas monitor
mode.

(7)

While

(8)

This mode will be canceled by repeating the same operation (1 to 4 above), turning
the product OFF, or waiting for 8 hours.

is displayed, the maintenance mode is being executed.

Carefully handle and make settings with the magnetic stick because the magnet is very
powerful. For details, refer to 3. Contents of Package.

23

 Zero Adjustment
 The external contact may operate. Therefore, set the product to maintenance mode if
needed.

MEMO

Conduct the zero adjustment in a place where there is no ambient gas.

(1)

While in gas monitor mode, press the MODE switch of the main unit first. Then press
the UP switch with the magnetic stick within approximately 2 seconds.

(2)

The main unit displays
first, followed by.
(The product is ready to work but nothing has been operated.)(3)

Press the UP or DOWN switch of the main unit with the magnetic stick and adjust thevalue to.

(4)

Press the ENTER switch of the main unit.

(5)
↓

↓

When the above items are displayed, the zero adjustment is completed.
(6)

Upon completion of the zero adjustment, the product will automatically return to gas
monitor mode.

 If an error is displayed, refer to 10. Trouble Alarm.
 Carefully handle and make settings with the magnetic stick because the magnet isvery powerful. For details, refer to 3. Contents of Package.

24

 Span Fine-tuning
MEMO

Be sure to conduct the zero adjustment before performing span fine-tuning.

CAUTION The external contact may operate during span fine-tuning. Set the product tomaintenance mode or release the interlocks of the external devices if needed before
performing span fine-tuning.
 Only your local representative’s maintenance service members or personnel who havecompleted a maintenance seminar can perform fine-tuning.

Apply calibration gas corresponding to the equipment.

Calibration cap
 Calibration gas(7)

Sufficiently stabilize the gas.

(8)

While in gas monitor mode, press the MODE switch of the main unit first. Then press
the UP switch with the magnetic stick within approximately 2 seconds.

(9)

The main unit displays
first, followed by.
(The product has completed starting but nothing has been operated.)
Example: After zero adjustment,
will be displayed.

(10) Press the UP or DOWN switch of the main unit with the magnetic stick and adjust thevalue to.
(11) Press the ENTER switch of the main unit.
(12) The main unit displays

first, followed by the present gas concentration.

(13) Press the UP or DOWN switch of the main unit with the magnetic stick, and adjust thedisplay of the main unit to the actual span gas concentration.
(14) Press the ENTER switch.
(15) The span fine-tuning is completed whenis displayed.

(16) Upon completion of the span fine-tuning, the product will automatically return to gas
monitor mode.
(17) Remove the gasbag.
 Perform span rough adjustment if

oris displayed.

 If an error is displayed, refer to 10. Trouble Alarm.
 Carefully handle and make settings with the magnetic stick because the magnet isvery powerful. For details, refer to 3. Contents of Package.

25

 Span Rough Adjustment
 Perform span rough adjustment if

oris displayed.

CAUTION The external contact may operate during span rough adjustment.
Before performing span rough adjustment, set the product to maintenance mode orrelease the interlocks of the external devices if needed.
 Only your local representative’s maintenance service members or personnel who havecompleted a maintenance seminar can perform span rough adjustment.

(1)

Apply calibration gas corresponding to the equipment.

(2)

Sufficiently stabilize the gas.

(3)

While in gas monitor mode, press the MODE switch of the main unit first. Then press
the UP switch with the magnetic stick within approximately 2 seconds.

(4)

The main unit displays
first, and displays.
(The product is ready to work but nothing has been operated.)
Example: After zero adjustment,
will be displayed.

(5)

Press the UP or DOWN switch of the main unit with the magnetic stick and adjust thevalue to.

(6)

Press the ENTER switch of the main unit.

(7)

The main unit displays(8)

Press the UP or DOWN switch of the main unit with the magnetic stick, and adjust thedisplay of the main unit close to the actual span gas concentration.

(9)

Press the ENTER switch.

first, and displays the present gas concentration.

(10) The span rough adjustment is completed whenis displayed.

(11) On completion of the span rough adjustment, the product will automatically return togas monitor mode.
(12) Remove the gasbag.

MEMO
Precise adjustment is not performed only by span rough adjustment. Perform spanfine-tuning after span rough adjustment.
 If an error is displayed, refer to 10. Trouble Alarm.
 Carefully handle and make settings with the magnetic stick because the magnet isvery powerful. For details, refer to 3. Contents of Package.

26

 Full-scale and Alarm Set Value Display
 The full-scale and alarm set values are only displayed. They cannot be changed.

(1)

While in gas monitor mode, press the MODE switch of the main unit first. Then press
the UP switch with the magnetic stick within approximately 2 seconds.

(2)

The main unit displays
first, and displays.
(The product is ready to work but nothing has been operated.)
Example: After zero adjustment,
will be displayed.

(3)

Press the UP or DOWN switch of the main unit with the magnetic stick and adjust thevalue to.

(4)

Press the ENTER switch of the main unit.

↓↓
Full scale↓↓
Alarm set value(5)

When the above items are displayed in sequence and repeatedly, the user can checkthe full-scale and alarm set values.

(6)

After the full-scale and alarm set values are displayed, the product will automatically
return to gas monitor mode.
 Carefully handle and make settings with the magnetic stick because the magnet isvery powerful. For details, refer to 3. Contents of Package.

27

 Test Mode Test values are adjusted and used for tests in this mode.

CAUTION The external contact may operate while the product is in test mode.
Before setting the product to test mode, set the product to maintenance mode or release
the interlocks of the external devices if needed.

(1)

While in gas monitor mode, press the MODE switch of the main unit first. Then press
the UP switch with the magnetic stick within approximately 2 seconds.

(2)

The main unit displays
first, and displays.
(The product is ready to work but nothing has been operated.)
Example: After zero adjustment,
will be displayed.

(3)

Press the UP or DOWN switch of the main unit with the magnetic stick and adjust thevalue to.

(4)

Press the ENTER switch of the main unit.
↓
Test value(5)

When the above items are displayed, the test operation of the product in aconcentration range from 10% to 110% of the full scale.
The test operation of the product is possible in a concentration range from 200 to
2200 ppm if the full scale of the product is 2000 ppm.
The test operation of the product is possible in a concentration range from 10%LEL
to 110%LEL if the full scale of the product is 100%LEL.

(6)

Press the UP or DOWN switch of the main unit and set the desired calibration
concentration. Then the test will start.
If the setting is outside the operating range,orwill be displayed.

(7)

To quit the test mode, press the ENTER or MODE switch.

(8)

When the test is finished with the ENTER switch pressed, the tested value will besaved.
When the test is finished with the MODE switch, the previously saved value willremain.
 Carefully handle and make settings with the magnetic stick because the magnet isvery powerful. For details, refer to 3. Contents of Package.

28

11-4.

Replacement of Sensor UnitWARNING Be sure to turn OFF the indicator unit, signal converter or main body equipment before
replacing a sensor unit. Otherwise, they may become a source of ignition.
 Be sure that the sensor and the sensor connector have been firmly connected to thedetector before the power is turned on. If the sensor and the detector are incorrectly
connected, the detector cannot detect gas.
 The dimensions of flameproof joint between casing and casing cover of KD-12 flameproof
housing are exceeding the minimum requirements stated EN/IEC60079-1. Please contact
the manufacturer for inspection, repair and/or adjustments of this flameproof.
？

CAUTION Only your local representative’s maintenance service members or personnel who havecompleted a maintenance seminar can replace the sensor unit.
 The external contact may operate when replacing the sensor unit if the sensor output is
not stable. Release the interlocks of the external devices if needed.
 Make sure that the mesh of the sensor casing is free of dirt or dust. Clean the meshbefore installing the sensor casing to the detector.


Be sure to handle the sensor unit with care. Do not drop or throw the sensor unit. Failure
to do so may lead to broken wire or sensor failure.

 When removing or mounting the sensor unit, do not twist the harness of the sensor
connector.
 When closing the casing cover, make sure that the power supply cord, harness, or O-ringis not caught by the casing cover.

MEMO Return the used sensor unit to your local representative.
 Calibrate the sensor unit after replacement.
 The sensor may need some time to stabilize after replacement. Energize the detector toallow the sensor to stabilize, then perform the zero adjustment and the span adjustment.
 To do calibration, always perform zero adjustment first, and then perform span
adjustment.
 If any error is displayed, refer to 10. Trouble Alarm.

2911-4. Replacement sensor unit (Continued)(1)

Turn OFF the power supply connected to the product.

(2)

Rotate the sensor casing in the direction of the arrow and remove it.

(3)

Pull down and remove the sensor as shown in the photo below.

(2) Rotate the sensor casing(3) Pull down the sensor(4)

Insert the sensor to the main body while checking the positions of the pins and theholes.

(5)

Install the sensor casing. Make sure that that the mesh of the sensor casing is free ofdirt or dust. Clean the mesh before installing the casing.

(4) Insert the sensor(5) Install the sensor casing

MEMO

 Return the used sensor unit to your local representative.

30

12.

Troubleshooting Before requesting repairs, refer to the following table. Consult your New Cosmos
representative if the product does not return to normal after taking the corresponding
remedies shown below or if the defective condition is not found in the table.
 If the product goes into an unintended mode at the adjustment or setting stage, stop
operating the product immediately and consult the system administrator.
Defective condition

Probable cause

The green power lamp is
not lit.

RemedyIncorrect wiring
connection.

Check and redo thewiring.

Low-voltage state

Check the power supply
voltage.

The product is inmaintenance mode.

Return the product togas monitor mode.

The product is inmaintenance mode.

Return the product togas monitor mode.

Incorrect wiring
connection.

Check and reconnect thewiring.

The alarm point setting
is wrong.

Check the alarm setting.

The analog signal does
not change

The product is in test
mode.

Return the product togas monitor mode

A value andare flashing alternately.

The sensor output ishigh.

The concentration of gas
is in excess of the fullscale. Check theambient environment.

The yellow LED lamp to
indicate an error is flashedand the error code isdisplayed.

The detected gas
concentration andare flashingalternately.

There is no alarm contact
output.

The sensor connector
has come off.

A value andflashing alternately.

areNo adjustment or setting ispossible.

Check the sensor
connector is firmly
connected.

Reference pageP. 12 - 15
Wiring andConnection

P. 23
Maintenance
Mode
P. 23
Maintenancemode
P. 12 - 15
Wiring andConnection
P. 27
Full-scale andAlarm Set Display
P. 28
Test mode

P. 6
Name of terminal
block joint

The sensor output is low.

Conduct zeroadjustment after
checking that the airaround the product is notcontaminated with gas.

P. 24
Zero adjustment

The product is operated
during the initial delay
time.

Operate the productafter 1 minute initialdelay time.

Ｐ. 17
Display at Start-up(Initial Delay)3113. Specifications
Model

KD-12

Detection principle

Non-dispersive infrared sensor (NDIR)

Sampling method

Diffusion type

Detection gas

Depends on the specifications

Detection range

Depends on the specifications.

Gas concentration
display

Four-digit digital LED display

Alarm set value

Depends on the specifications.

Alarm accuracy 25% of alarm set value under identical conditions.

Alarm delay Within 30 seconds with gas concentration that is 1.6 times as high as thelevel of alarm set concentration.

Warning display

 Gas alarm (one stage only):
Red LED lamp flashes
 Trouble alarm (sensor disconnection, sensor zero drop, power supply voltage
error, or internal EEPROM communication error):
Yellow LED lamp flashes

External output

Gas concentration analog signal
 4 to 20 mA DC (common to the negative side of power supply)
 0.9 mA DC or less at the time of Trouble alarm.
 Make sure that the load resistance of the analog signal is less than 300 ohm
including the wiring resistance.
Gas alarm contact (one stage only) 1a no-voltage contact output/Non-latching Rated load: 0.5 A at 250 VAC or 0.5 A at 30 VDC (resistance load)

Equipment or Protective Directive 2014/34/EU
System intended for
SI 2016 No.1107
use in Potentially
Explosive Atmospheres
Explosion-proof class

II 2 G Ex db IIC T5 Gb (ATEX)II 2 G Ex db IIC T5 Gb (UKEx)
Ex db IIC T5 Gb (IECEx)

Approvals

EU-Type Examination Certificate Number : DEMKO 08 ATEX 143870 X(CE 2776
II 2 G Ex db IIC T5 Gb)
UKEx Examination certificate: CML 21UKEX11353X(UKCA 2503
II 2 G Ex db IIC T5 Gb)
EMC : EN61000-6-4:2007+A1:2011, EN50270:2015 - Type 2
Performance testing : The measuring function of the KD-12 gas detector for
explosion protection, according to Annex II clause 1.5.5, 1.5.6 and 1.5.7 of the
Directive 2014/34/EU, is not covered in this certificate.
IECEx : ULD 13.0001X (Ex db IIC T5 Gb)

Harmonised/Designated standards

EN IEC 60079-0:2018, EN 60079-1:2014
IEC 60079-0:2017 Edition 7.0, IEC 60079-1:2014 Edition 7.0

Degree of protection

IP65 (Exterior)

Applicable cable

Cable outer diameter (10 to 13 mm)
 In the case of a 5-conductor cable (for power supply, gas concentration
analog signal, and gas alarm contact): CVV-S 1.25 mm2.
 In the case of a 3-conductor cable (for power supply and gas concentration
analog signal) CVV-S 2 mm2 or 1.25 mm2

32

Operating temperatureand humidity ranges

 Temperature: 10C to 50C Humidity 10% to 90% RH (0 to 50C).
(No radical temperature or humidity changes and no condensation)

Power supply

24VDC (18 to 30 VDC)

Power consumption

3W max.

Size

128 (W) x 120 (H) x 68 (D) mm (excluding protruding parts)

WeightApprox. 1.3kg

Mounting method

Wall mounting

The above specifications are subject to change without notice.
If your specifications are nonstandard, refer to the delivery specifications.

14.

Markings of explosion-proof-Nameplate detail-Serial number label detail-Rated label detail-Certificate label detail-Warning label detail-Harmonised/Designated standards
EN IEC 60079-0:2018
EN 60079-1:2014
IEC 60079-0:2017 Edition 7.0
IEC 60079-1:2014 Edition 7.0

33

15.

Warranty

New Cosmos Electric Company Limited (hereafter referred to as “New Cosmos”) offers thefollowing as the sole and exclusive limited warranty available to the Customer.
This warranty is in lieu of, and the Customer waives, all other warranties of any kind or
nature, expressed or implied, including without limitation any warranty for merchantability or
fitness for a particular purpose. The remedies set forth herein are exclusive.
New Cosmos warrants to the original purchaser (Customer) and no other person or entitythat the gas detection product supplied by New Cosmos shall be free from defects inmaterials and workmanship for a period of one (1) year from the date of purchase. This
warranty does not apply to consumables, including but not limited to fuses and filters.
Certain other accessories not specifically listed here may have different warranty periods.
If after examination of an allegedly defective product returned to New Cosmos, with freight
prepaid, should it be found that the product fails to conform to this warranty, the Customer’s
only remedy and New Cosmos’s only obligation shall be, at New Cosmos’s sole discretion,
replacement or repair of the non-conforming product or refund of the original purchase priceof the non-conforming product. In no event shall New Cosmos be liable for any other special,incidental, or consequential damages or losses of any kind whatsoever, including but notlimited to loss of anticipated profits and any other loss caused by reason of non-operation of
the product.
This warranty is valid only if the product is maintained and used in accordance with New
Cosmos’s instructions and recommendations. New Cosmos shall be released from all
obligations under this warranty in the event repairs or modifications are made by persons
other than its own or authorized service personnel or if the warranty claim results fromphysical abuse or misuse of the product.

16.

Life Expectancy

 The design period longevity under a general environmental condition of this container isabout 5 years from purchase. The design life expectancy after the guaranteed term
passes is not the one to guarantee this. It is only a guide when a prescribed gas is
proofread and it uses it. It might be impossible to use between the proofreading and theproofreading schedule for the next term.
The life of the Non-dispersive infrared sensor incorporated in the KD-12R isapproximately five years after the date of purchase.
The sensor may not detect gas correctly with the lapse of approximately five years.
Replace the sensor at intervals of approximately five years. The life of the sensor is
specified on the condition that the sensor is serviced properly and that the sensor is not
exposed to high-density gas or toxic gas. New Cosmos, however, does not guarantee thespecified life of the sensor.

34

17.

Detection principle

Non-dispersive infrared sensor (NDIR)
The molecule which is consisted of chemical atom, gas, has a specific absorption
wavelength in 1～20μm Infrared region.
This absorbed amount of infrared ray is proportional to gas concentration. (Beer-Lambertlaw), so it is available to major gas concentration from the absorbed amount.
It is available to find the gas selectively by using the optical filter which is able to passthrough the infrared wavelength that the object gas absorbed.
Below it shows the illustrating model of NDIR.

①赤外線光源1.Infrared
light source③窓⑤光学フィルタ
3.Window
5.optical filter⑦演算器
7.Computing unit
4.Cel
l
④セル

ＣＰＵ

⑥赤外線式センサ
6.infrared sensor

2.light control part②光源制御部① In the infrared light source, strength is given to the emission of infrared rays in a certain
amount of cycle by ②the source of light control part.
The radiated infrared light penetrates ③in the window and ④inside of the cell.
It through the infrared light of a specific wavelength ⑤in optical filter, and measure theabsorbed amount ⑥in the infrared sensor. Measured electrical signal is converted to theconcentration ⑦in the computing unit.

35

18.

Glossary

Indicator / Alarm unit:

A unit that receives signals from the gas detector and indicatesgas concentration and alarms.

Detector:

A unit that detects gas concentration and converts it to electric
signals.

Backup power source device:

A device that supplies power to the gas detector,

indicator / alarm unit in order to maintain its performance during
a power failure.
Flow meter:

A meter to measure air flow in gas sampling pipe.

Gas collector:

A gas collecting probe that enhances gas collection efficiency
and blocks water and dust.

Diffusion type:

A method to detect gas by utilizing convection and diffusion ofgas.

Explosion proof construction:

A totally enclosed structure. When an explosive gas

explodes in a container, the container can resist the pressure
and prevent the ignition of explosive gases outside of it.
Preset alarm value:

A preset value for the alarm to go off when gas concentration
reaches a certain value.

Gas to be detected:

Gas that is detected and indicated which sets off an alarm.

Detection range:

Range of gas’s concentration that can be indicated and set off
an alarm.

Alarm accuracy:

Difference

betweenthepreset

alarm

value

and

gas

concentration when an alarm actually occurs or as thepercentage of the difference compared to the preset alarm
value.
Response time:

Time it takes from when the gas detector is exposed to a gas
with a concentration higher (lower) than the preset alarm value
until an alarm goes off.

Temperature range:

Range of temperature where the equipment can perform its
functions.

Maintenance and inspections:

Work to guarantee that the equipment perform its

required functions.

36

Calibration gas:Gas used to calibrate scales of the equipment.

Peak hold:A function to constantly update and hold the peak value of input
signals.

Hazardous area:

An area in a plant or facility with a hazardous atmosphere
where explosive gases may mix with air and explode or start afire. An area where gas may be present.

Non hazardous area:

An area where electric equipment that has no potential to createa hazardous atmosphere.

Hazardous atmosphere:

Atmosphere within the explosive limit where explosive gas andair are mixed.

LEL:

Lower Explosive Limit.

The lowest concentration of flammablegas that will explode when mixed with air and ignited.
(Quoted from gas detection terms and detector tube gas meter terms used by the Industrial
Gas Detector Alarm Association.)

37

MEMO

38

Manual Revision History
Edition No.

Date

Revision

GAE-048-00

September 201300

GAE-048-01

November 2016

01

GAE-048-02

August 201702

GAE-048-03

October 201803

GAE-048-04

January 201904

GAE-048-05

July 201905

GAE-048-06

December 201906

GAE-048-07

April 2021

07

GAE-048-08

September 2022

08

Additional copies of this instruction manual may be purchased.
Contact New Cosmos or its authorized representative for ordering.
Distributor:

Manufacturer:
New Cosmos Electric Co., Ltd.
2-5-4 Mitsuya-naka Yodogawa-ku
Osaka 532-0036, Japan
URL: http://www.newcosmos-global.com