Oxygen Detector

KS-7O
Instruction Manual
Keep this manual for easy reference.
Carefully read this manual prior to use.
This manual describes the standard model. If your unit has end-user-specificoptions, this manual will be superseded by your delivery specifications.

Instruction Manual No.
GAE-052-06
June 2023

Table of Contents
1. Introduction ................................................................................................................................1
2. General Precautions ..................................................................................................................2
3. Package Contents .....................................................................................................................3
4. Unit Dimensions and Components ............................................................................................4
4-1. Outer Appearance ..................................................................................................................4
4-2. Inner Components ..................................................................................................................5
5. Installation .................................................................................................................................6
6. Wiring ........................................................................................................................................96-1. Pin Terminal/Insulating Sleeve Installation ...........................................................................10
6-2. Wire Connection/Disconnection to/from Terminal Block ...................................................... 11
6-2-1. Power Terminal Block ....................................................................................................... 11
6-2-2. External Output Terminal Block ......................................................................................... 11
6-3. Cable Tie Installation ............................................................................................................ 11
6-4. AC Power Cable (PC0125) Wiring Procedure .....................................................................12
7. Operation .................................................................................................................................13
7-1. Precautions before Use ........................................................................................................13
7-2. Operating Procedure ............................................................................................................13
7-3. LCD Operation .....................................................................................................................15
7-3-1. LCD ...................................................................................................................................15
7-3-2. Normal Operation Status ...................................................................................................15
7-3-3. Full Scale and Alarm Set Values Display ..........................................................................16
7-3-4. Peak Value Display and Reset ..........................................................................................16
7-3-5. Operation during Gas Alarm .............................................................................................16
7-4. User Mode ............................................................................................................................17
7-4-1. User Mode Operation ........................................................................................................17
7-4-2. Switching Maintenance Mode On/Off [Mode1] .................................................................18
7-4-3. Zero Adjustment [Mode 2] .................................................................................................19
7-4-4. Span Adjustment (21.0vol% Adjustment) [Mode 3] ...........................................................19
7-4-5. Alarm Test [Mode 4] ..........................................................................................................20
7-4-6. Alarm History [Mode 5] ......................................................................................................21
7-4-7. Clock Setting [Mode 6] ......................................................................................................22
7-5. Maker Mode .........................................................................................................................23
7-5-1. Maker Mode Activation ......................................................................................................23
7-5-2. Operating Time Refresh ....................................................................................................23
7-5-3. Alarm Set Value Change ...................................................................................................24
8. Maintenance ............................................................................................................................26
8-1. Inspection Contents and Frequency ....................................................................................26
8-2. Sensor/Backup Battery/Clock Battery Replacement............................................................28
9. Troubleshooting .......................................................................................................................31
10. Specifications.........................................................................................................................33
11. Warranty ................................................................................................................................34
12. Expected Sensor Life ............................................................................................................34
13. Detection Principle ................................................................................................................35
14. Glossary ................................................................................................................................36
15. Proper Product Disposal at End of Life .................................................................................37

1. Introduction
Thank you for purchasing the New Cosmos KS-7O oxygen detector.
To ensure safe and reliable operation, please read this instruction manual prior to use.
This unit detects oxygen leakage/deficiency in working environments, e.g., semiconductor
manufacturing plants and laboratories, and relays the oxygen concentration value as an analog
signal (4-20mADC) to external devices while simultaneously displaying the concentration value on
its display.
Oxygen levels are monitored, and if the concentration reaches a preset level, the unit will produce
audio/visual alarms and activate relay contacts.

This manual uses Danger, Warning, Caution and Note symbols to draw attention toprocedures, materials, methods, and processes, which require particular attention.
DANGER : Indicates an imminently hazardous situation that can result indeath or serious injury.
WARNING : Indicates a potentially hazardous situation that may result in deathor serious injury.
CAUTION : Indicates a hazardous situation that may result in minor injury orproperty damage.
NOTE: Provides information on product handling.

-1-2. General Precautions
Carefully read this manual prior to use.
Follow the precautions below to ensure safe operation.
Only use this product in accordance with the applicable laws and regulations.
Only a qualified electrician with knowledge of wiring and installation procedures should perform
wiring and installation.
WARNINGIn the event of a gas alarm, follow the safety procedures in accordance with yourcompany's regulations.
This product is not explosion-proof and should not be installed in a hazardous area.
Secure the cover by tightening the two fastening screws. Proper gas detection is notpossible if the cover is not tightly closed.
CAUTION
Do not disassemble, modify, or alter the structure of this unit or its electrical circuits.
Doing so may compromise the performance of the product.
This product is not drip-proof and should be kept away from water.
-layermonitoring software, perform a 21% suppression setting using the high-layer monitoring
software.
ranges from 250 to 500 (contingent on full scalesetting). Because of the difference in resolution or number of displayed gas
concentration digits between this product and high-layer monitoring software, orconnected impedance, some errors in displayed gas concentration value may beobserved.
If the fault threshold needs to be set via analog output, set it to 1.0 mA.
To comply with JIS T 8201:2010 (Japanese Industrial Standard), your unit should be
configured for manual-resetting. Specify manual-resetting type at time of order. If a
self-resetting type is chosen and manual-resetting is maintained using a high-layer
system, a self-resetting type of detector can be used to comply with this standard.

NOTE
Operation during power outage
In the event of a power outage during operation, the detector will cease operation if the
backup battery is not installed. The detector will automatically resume operation once
power is restored, as long as the main power switch, under the cover, is in the on (up)position. A backup battery is included in the package (not pre-installed) when delivered.
Install it into the detector if the detector needs to continue running during a power outage.
If the backup battery level becomes very low while the detector operates on the backup
LCD. If the detector
continues operating while "E-B" is displayed, it will cease operation automatically toprevent over-discharge. In this case, the detector will not automatically resume operationeven if power is restored.
Remove the backup battery from the detector before a planned power outage etc., if thedetector is expected to operate on the backup battery for an extended period of time.
Refer to 8removal/
ill not be affected
whether the backup battery installed or removed.
-2-

3. Package Contents
The following items are included in a standard package. If any items are missing or damaged,please contact New Cosmos or its authorized representative for replacement.
Item

Quantity

Description

Oxygen detector

1

KS-7O

Mounting screw

2

M5x12 with spring washer (wall mounting)

Cable tie

1

To be used to bundle electric cables

Pin terminal

9

To be crimped to cables and inserted into the terminal
block

Insulating sleeve9

To be installed in a crimped pin terminal to provide
insulation

Instruction manual

1

This manual

Inspection certificate

1Backup battery

1CR2 lithium battery

1

100 VAC power cable with 2-pin power plug at one end
and two pin terminals at the other end
Length: 2.5 m
Note: AC power cable is not included unless specified at
the time of order, even though your unit has AC power
option.

AC power cable(Optional)-3-4. Unit Dimensions and Components
4-1. Outer Appearance

Dimensions are in mm.

Item

Component

1

Cover

2

Screw cover3

Gas detection port

4

Status indicator(red/amber/green)

5

LCD

6

AL2 alarm LED (red)7

AL1 alarm LED (amber)

Description/Function
Slide up and lift the cover to access to the main power switch and towire external cables. This cover is normally closed.
Houses one mounting screw, and two fastening screws that attach thecover to the unit. This cover is normally closed.
Gas inlet to the oxygen sensor.
During normal operation all three green internal LEDs are lit. In theevent of an 1st/2nd stage gas alarm, four internal amber/red LEDs
light sequentially.
Displays oxygen concentration, parameter values, error code, andstatus icons.
Flashes red in the event of a 2nd stage gas alarm. The LED will
become solid if reset by pressing the RESET button.
Flashes amber in the event of a 1st stage gas alarm. The LED will
become solid if reset by pressing the RESET button.

8(Up) button

During normal operation, press to display the highest peak value ofoxygen concentration after powering-up on the LCD.
Used for making settings in combination with other button operation.

9(Down) button

During normal operation, press to display the lowest peak value ofoxygen concentration after powering-up on the LCD.
Used for making settings in combination with other button operation.

10

RESET button

11
12

POWER button
Speaker opening

13

Cable entry (3 places)

14

Maintenance button

During normal operation, press to display the full scale and alarm set
values. Used for muting an on-going audio alarm.
Press and hold for 3 seconds to turn on/off the detector.
Opening for audio.
Make a cutout (cable entry) with a nipper to connect external cables tothe terminals.
Recessed button used for making settings.
-4-4-2. Inner Components

Item

Component

Description/Function
Slide up and lift the cover to access to the main power switch andto wire external cables. This cover is normally closed.
Houses one mounting screw, and two fastening screws that attach
the cover to the unit. This cover is normally closed.
Located under the screw cover.
Screws that attach the screw cover to the unit.

1

Cover

2

Screw cover3

Fastening screw (2 places)

4

Terminal block

Connect to external wiring.

5

Main power switch

Turns on/off the main power.

-5-5. Installation
WARNING
This product is not explosion-proof and should not be installed in a hazardous area.

CAUTION
Avoid strong mechanical shock, impact or vibration to the detector by dropping or bumping.
Failure to do so may impair the performance of the detector.
Do not install the detector in the following conditions.
- Outdoors- Exposure to water spray- Outside the following operating temperature/humidity-10 to +40 °C (no rapid temperature change)
30 to 85% RH (no condensation)- Presence of corrosive gas- Exposure to impact or vibration- Presence of high frequencies or a magnetic field- Exposure to electrical noise
Install the detector in a location that ensures easy access for maintenance.
For detecting oxygen deficiency, the detector should be installed at head height in a place
free from obstruction to the gas detection port.
When used in a measurement environment where the atmospheric pressure is different
from the standard atmospheric pressure, e.g., at a high altitude, the measurement value
should be adjusted to compensate for the oxygen sensor s pressure dependence.
Secure the cover by tightening the two fastening screws. Proper gas detection is notpossible if the cover is not tightly closed.

NOTE

Leave a distance of more than 30mm from each side of the detector for
removal purpose.
Leave a distance of more than 50mm from the top of the detector to allow thecover to slide open.
Leave enough space for cable wiring below the detector.

-6-

50
50

Space forSensorcover to slide

Mounting hole
Mounting hole

Mounting hole
Cable entry

Dimensions are in mm.

Wall-mount the detector using two M5 mounting screws (pitch: 134) according to the following
procedure.
1. Open the screw cover.
2. Loosely install the mounting screw (top).
3. Loosen the two fastening screws.
4. Slightly pull the cover forward.
3. Loosen the two fastening screws
1. Open the screw cover
Screw cover

2. Loosely install themounting screw (top)

4. Pull the cover forward
Cover

-7-

5. Slide the cover up (cover is open).
6. Firmly tighten the mounting screw (bottom) to secure the detector to the wall.
7. Slide the cover down (cover is closed).
7. Slide the cover down

5. Slide the cover up

6. Tighten the mounting screw (bottom)

8. While pressing down the cover toward the case,
9. tighten the mounting screw (top).
10. Secure the screw cover to the case with the two fastening screws.
11. Close the screw cover.
10. Tighten the two fastening screws
9. Tighten the mounting screw

8. Press down the cover
Case

CAUTION
Secure the cover by tightening thetwo fastening screws. Proper gas
detection is not possible if the cover
is not tightly closed.

-8-6. Wiring
WARNING
Remove any power source during wiring work to prevent electric shocks.
After wiring is completed, close the detector s cover to prevent electric shocks.
CAUTION
New Cosmos is not responsible for the cost or any damage resulting from controllingexternal equipment (e.g., interlock) by using the oxygen concentration outputs (e.g.,analog output, alarm relay contact output) from this product.
Connect wires to their corresponding terminals by referring to the marking on the terminal
block.
Keep the connection cable away from the electrical power line.
When using with external devices, isolate the product s 4-20mA analog output from powerlines of external devices in order to prevent inflow current and noise.

The knockout holes for cable entry are provided
on the back and bottom of the unit, and can beremoved using a nipper.
Use a shielded cable (with 0.5 to 1.25 mm2 wires)up to 500 m in length with an outside diameter of
10.5 mm or less.
NOTE

Refer to page 12 for the wiring procedure
for the optional AC power cable.
Refer to 7-3-2
on page 15 for the operation of the backup
battery.
Ex. NO contacts

Signal+Knockout hole on the back

ZA1 ZA2 TA

COM

D C

AC

DC

R

P

S

N
E

E
+

Signal

RN

S

SP

R

ZA1
ZA2

Knockout hole on the bottom+

Power supply
24 VDC or 100 VAC

Earth terminal for grounding the detector+

Analog output
4-20mADC

1st stage alarm relay contact(Dry NO or NC)
2nd stage alarm relay contact(Dry NO or NC)

TA

Fault alarm relay contact (Dry NO or NC)

COM

CommonDC

Not used

NO: Normally Open

-9-

NC: Normally Closed

6-1. Pin Terminal/Insulating Sleeve Installation
Recommended parts/tools
Part

Model (Manufacturer)

Description
Shielded cable (with 0.5-1.25 mm2 wires)Electric cableOuter diameter: 10.5 mm or less
(Included in package)

Pin terminal

TC1.25-16 (Nichifu)

Insulating sleeve

VC1.25 (Nichifu)(Included in package)

Crimping tool

NH1 (Nichifu)

1.25

Used for 0.25-1.65 mm2 twisted wire

Terminal block (reference)
Part
Power terminal block
External output terminal block

Model (Manufacturer)
ML-1400-S1L-3P(Sato Parts)
FFKDSA1/H1-5, 08-8
(Phoenix Contact)

Description
Dia. 0.65-1.6 mm
Dia. 0.2-1.5 mm

1. Wire stripping
Strip the wire.
Recommended stripped wire length: 5.5 mm

5.5 mm

2. Pin terminal installation
Insert the stripped wire into a pin terminal until 1 mmof stripped wire can be seen from the end of the pins barrel.

Pin Terminal

3. Terminal crimping
Crimp the center of the barrel.
Barrel4. Insulating sleeve installation
Attach an Insulating sleeve to the crimped pin
terminal.
NOTE

Completely insert the pin terminal into
the insulating sleeve. Not doing so may
cause an insufficient pin length when
wired to the terminal block, which may
result in a poor connection.

- 10 -

Insulating sleeve
Completely insert

6-2. Wire Connection/Disconnection to/from Terminal Block
6-2-1. Power Terminal Block(Connection)

Insert each pin terminal to its
corresponding slot on the terminal block.

(Disconnection)

While pressing the release button with a
precision screwdriver (recommended tip
thickness: 2.6 mm), lift the pin terminal.

6-2-2. External Output Terminal Block(Connection)(Disconnection)

Insert each pin terminal to its
corresponding slot on the terminal block.

While pressing the release button with a
precision screwdriver (recommended tip
thickness: 3.0 mm), lift the pin terminal.

6-3. Cable Tie Installation
Use a cable tie for bundling the in-coming cables through thecable entry and secures wall.
The unit has a cable tie holder inside its case near the bottom.
Pre-install a cable tie by feeding it through the tie holder andmake a loop. To easily bundle the wiring of in-coming cables tothe terminal block, feed these cables through this loop andsecure to the case wall.

Cable tie

Cable entry- 11 -

6-4. AC Power Cable (PC0125) Wiring Procedure
1. Make a cutout (cable entry) on the bottom of
the unit with a nipper.
Note: The knockout holes for cable entry areprovided on the back and bottom of the unit,
and either can be used as cable entry.

2. Install a cable tie by feeding it through thetie holder and make a loop.

Cut here (2 places)
3. Ensure that the insulating sleeves arecompletely installed to the pin terminals of
the AC power cable.

4. Feed the AC power cable through the cableentry and the loop of the cable tie.

5. Insert the pin terminals into the slots(Nos. R and S) on the terminal block.
Note: Either pin terminal can be connected toeither slot.

6. Pull the cable tie to secure the AC power
cable to the case wall. Cut off the excess
strap with a nipper.

- 12 -

7. Operation
7-1. Precautions before Use
WARNING
Before tuning on the unit, confirm that the power supply is:
24 VDC±10% when DC power is used.
100 VAC±10% and 50/60Hz±10% when AC power is used.
CAUTION
Before turning on the unit, check that all wiring is correct. (Refer to 6. Wiring or delivery
specifications if provided.)Turn on the unit in clean air.
When the sensor output is not stable, the external relay contact may possibly activate
after the warm-up. To prevent possible activation of the external relay contact after the
warm-up is completed, release the interlocks of the external devices, as needed.
During the warm-up, the analog signal is output and the external relay contacts are
disabled.

7-2. Operating Procedure
1) Follow Steps 1, 3, 4, and 5 of 5. Installation
to slide up and open the cover (cover is not
fully opened).
1. Open the screw cover.
3. Loosen the two fastening screws.
4. Slightly pull the cover forward.
5. Slide the cover up (cover is open).

Screw cover
MaintenancebuttonCover2) Set the main power switch to the on (up)position.

Main powerswitchOpen3) Follow Steps 7, 8, and 10 of 5. Installa
to close the cover and tighten the screws.
7. Slide the cover down (cover is closed).
8. While pressing down the cover toward the case,
10. secure the screw cover to the case with thetwo fastening screws.

Status indicator
LCD

CAUTION
Secure the cover by tightening thetwo fastening screws. Proper gas
detection is not possible if the cover
is not tightly closed.

Maintenancebutton- 13 -

POWER button

4) Press and hold the POWER button for 3 seconds to turn on the detector (two beeps). The threegreen LEDs inside the status indicator start flashing and -- -- -- -- is displayed on the LCD. The
warm-up cycle lasts 30 seconds.

Warm-up cycle

Normal operation

5) When the warm-up cycle is completed, the three green flashing LEDs inside the status indicator
become solid, the gas concentration is displayed on the LCD, and normal operation starts.
6) Perform a span adjustment (21.0 vol%).
CAUTIONTo prevent a possible activation of alarm or external alarm relay contact, switch to the
Maintenance mode to ON before performing a span adjustment. (Refer to 7-4-2.
Switching Maintenance Mode On/Off .)Check that there is no gas present before span adjustment. Proper gas detection is notpossible if a span adjustment is performed in a gas atmosphere.
When a span adjustment is completed, switch the Maintenance mode to OFF. External
alarm relay contacts or audio alarm are not active while the unit is in the Maintenance
mode.
NOTE

Use a rounded pin (e.g., precision screwdriver) for pressing the maintenancebutton.

1. Enter the User mode. (Refer to 7-4-1. User Mode Operation )2. Switch the Maintenance mode to ON. (Refer to 7-4-2. Switching Maintenance Mode On/Off )3. Perform a span adjustment. (Refer to 7-4-4. Span Adjustment )4. Switch the Maintenance mode to OFF.
7) Perform an alarm test by referring to7-4-5. Alarm Test .
Confirm that an alarm activates.
8) To turn off the detector, press and hold the POWER button for 3 seconds to stop the operation,then set the main power switch to the off (down) position.
NOTE

Once the POWER button is turned off, the backup power is not available.
The backup power is activated if the main power switch is turned off, as long as
the POWER button is in the on position.

- 14 -

7-3. LCD Operation
7-3-1. LCD

2

3

5

4

6

7

8
1
Item

11

10

Icon/Display

9
Description/Function

1

Audio alarm icon

Always present

2

AL1 icon

1st stage gas alarm notification

3

AL2 icon

2nd stage gas alarm notification

4

Sensor replacement icon

Sensor needs to be replaced5

Backup battery icon

6

Backup battery level indicator

7

Concentration value and information

8

Unit of measurement

Unit is operating on the backup battery
Battery level of the backup battery used during power
outageOxygen concentration value, parameter values, error
code, etc.
A unit of gas concentration

9

Clock battery level indicator

Clock battery level is low

10

Alarm history icon

Alarm history is being accessed11

Maintenance mode icon

Maintenance mode is active

Operation buttons

7-3-2. Normal Operation Status
During normal operation the green status indicator is fully lit,
the gas concentration value is displayed on the LCD, and
the AL1 and AL2 alarm LEDs are off.
NOTE

When the detector operates on the backup
battery, unlike when it is driven by 24 VDC
or 100 VAC power supply,
The status indicator is not lit during
normal operation and it sequentially
flashes In the event of a 1st/2nd stage
gas alarm.
The analog output is 0 mA (no output).
The external relay contacts are disabled.
The audio volume is lower.

- 15 -

POWER button
RESET button(UP )button(DOWN) button
Maintenance button

7-3-3. Full Scale and Alarm Set Values Display
Press the RESET button (one beep) to display the full scale concentration , 1st stage gas alarm set
value , and 2nd stage gas alarm set value in sequence.

Full scale: 25.0 vol%1st stage gas alarm set value: 19.0 vol%2nd stage gas alarm set value: 18.0 vol%7-3-4. Peak Value Display and Reset
Press thebutton (one beep). The lowest peak value after powering-up and PEAK will be
displayed alternately.
NOTE

Press thebutton to display
the highest peak value after
powering-up.

(Ex. lowest peak value is 10vol%)To return to the normal gas concentration display, press the RESET button (one beep).
The display will show the full scale value and alarm set value, then return to the normal gas
concentration display.
To reset the peak value, press theat the same time (two beeps).
The peak value is reset then the display returns to the normal gas concentration display.

7-3-5. Operation during Gas Alarm
When the oxygen concentration reaches the alarm set value, the alarm LED flashes, the statusindicator sequentially-flashes and an audio alarm sounds.
NOTE

Audio alarm mute: If the RESET button is pressed during a gas alarm, the audio
alarm will be muted and the flashing alarm LED(s) will become solid. If the
RESET button is pressed and held, the alarm will not be muted.

There are two options to clear a gas alarm, manual-resetting and self-resetting. By default, thedetector is set to manual-resetting mode. Please specify the alarm clearance option at the time oforder, if necessary.
The alarm hysteresis range is 0.2vol%. The alarm will not be cleared until the oxygen
concentration exceeds the alarm set value by more than the hysteresis value. E.g., when the alarm
set value is 18.0vol% and an alarm is activated, the alarm will not be cleared until theconcentration reaches 18.3vol% or higher.
NOTE

Alarm relay contact reset: If the RESET button is pressed while theconcentration is outside the alarm set value, the alarm relay contact will return to
its normal position and the alarm LED will turn off.

- 16 -

< 1st stage alarm >Amber AL1 alarm LED flashes and the status indicator sequentially-flashes amber.
Audio alarm beep: Fast, high and low beep tones.
ZA1 alarm relay contact is closed. (When normally open contacts are used)< 2nd stage alarm >Red AL2 and A1 alarm LEDs flash and the status indicator sequentially-flashes red.
Audio alarm beep pattern: Very fast high and low beep tones.
ZA2 alarm relay contact closes and ZA1 alarm remains closed. (When normally open
contacts are used)

7-4. User Mode
During the User mode, gas detection, alarm operation, analog output, andcontact output activation are active as during normal operation mode.
However, audio alarm mute and alarm clearance are not active and cannot be
used.
Return to normal operation mode after using the User mode.

NOTE

7-4-1. User Mode Operation
To enter the User mode, press the maintenance button
while the unit is on. After one beep, 1 and its abbreviatedmode name MT will be alternately displayed.
NOTE

Use a rounded pin (e.g., precision screwdriver) for pressing the maintenancebutton.

To select the mode options, use theandbuttons.
To confirm your selection, press the maintenance button. To return to the previous step, press the
RESET button.
To execute the selected mode, press and hold the maintenance button for 3 seconds.
To return to the normal operation mode, press and hold the RESET button for 5 seconds.
Mode
1
2
3
4
5
6

Mode name
Switching maintenance mode on/off
Zero adjustment
Span adjustment
Alarm test
Alarm history
Clock setting

Abbreviated mode nameMT
0.0 vol%
21.0 vol%
AL T
AL H
DATE

- 17 -

7-4-2. Switching Maintenance Mode On/Off [Mode1]
WARNING

During the Maintenance mode, the external relay contacts and audio alarm are disabled.
Turn off the Maintenance mode during normal operation.

1) Enter the User mode. Press the /button to
select 1 . MT and 1 will be alternately
displayed.
2) Press the maintenance button (one beep).
OFF will flash.
button (one beep).
3) Press theON will flash.

4) Press and hold the maintenance button for 3
seconds (beep pattern: short long short short) to
confirm the selection.
The maintenance icon is displayed, and 1 andMT will be alternately displayed, indicating thatthe unit is in the Maintenance mode.
NOTE

If the unit is returned to normal operation mode
while in the Maintenance mode, the_ _ _ _ will be
alternately displayed and the maintenance icon
will remain displayed.

5) To exit the Maintenance mode, take Steps 1) to 4)
above to switch the mode fromN to "OFF".
Confirm the maintenance icon has turned off.

- 18 -

Maintenance icon

7-4-3. Zero Adjustment [Mode 2]
CAUTION
On-site zero adjustment is not necessary as units have been zeroed when shipped out.

7-4-4. Span Adjustment (21.0vol% Adjustment) [Mode 3]
CAUTION
Perform a span adjustment in clean air.

1)

Press the/button to select 3 (eachpress of the button is followed by one beep).
21.0vol% (span adjustment concentration)and 3 will be alternately displayed.

2)

Press the maintenance button (one beep).
The measured oxygen concentration (vol%)will be displayed.

3)

Check that there is no gas present. Press andhold the maintenance button for 3 seconds tostart a span adjustment (beep pattern:
short-long-short-short). 21.0vol% and 3 willbe alternately displayed, indicating that span
adjustment is complete.

- 19 -(Span adjustment value is 21.0vol%)(Ex. Current concentration is 20.8vol%)7-4-5. Alarm Test [Mode 4]
When an alarm test is executed, the alarm test value (concentration) will be displayed on the LCD,
and corresponding analog output and alarm outputs (external relay contacts, audio alarm, alarmLEDs) will activate. This will allow the user to test the alarm operation.
NOTE

If the unit is in the Maintenance mode, the external relay contacts and audio
alarm are disabled (alarm LEDs and analog outputs are active).
CAUTIONAn alarm test activates the external relay contacts of the detector. If the detector s external
relay contacts are used to operate the interlocks, etc., of the external devices, release theinterlocks beforehand, as needed to prevent a possible activation of the interlocks. Notify
those concerned before starting an alarm test or inspection.
button1) Enter the User mode. Press the /to select 4 (each press of the button isfollowed by one beep). AL T and 4 will be
alternately displayed.
2) Press the maintenance button (one beep).
The current alarm test value (vol%) will be
displayed.
(Ex. Test value is currently set to18vol%)3) To change the alarm test value (vol%), press/
button.
the
NOTE

To increase/decrease the test value,/
button. Holding thepress thebutton will continuously
increases/decreases the value.

(Ex. Test value is changed to 10vol%)4) Press and hold the maintenance button for 3 seconds
to start an alarm test (two beeps).
5) To cancel the ongoing alarm test, press the
RESET button (one beep). The current alarm
test value (vol%) will be displayed.
(Note: If the RESET button is pressed and held,
the alarm will not be cancelled and the unit will
return to normal operation mode.)6) To change the test value, repeat Steps 3) to 5).
7) Press and hold the RESET button for 5 seconds
to return to normal operation mode.

- 20 -(Ex. Test value is currently set to 10vol%)7-4-6. Alarm History [Mode 5]
Up to the 10 most recent alarm events can be displayed (automatically updated).
For each alarm event, the following sequence of information is displayed: peak value (vol%) during
the alarm, starting and ending times (year/month/day/time) of the alarm.
Press the RESET button to return to the previous screen.
button to select1) Enter the User mode. Press the /5 (each press of the button is followed by one beep).
AL H and 5 will be alternately displayed.
2) Press the maintenance button (one beep) to display
the alarm history. The most recent alarm event
number H1 will be displayed. If there is no alarm
history event, INIT will be displayed.

(No alarm events)

button (each press of the button is3) Use thefollowed by one beep) to select (display) the desired
alarm event from H1 to H10.
NOTE

(Ex. H1 is selected)

Each press of the
button cycles through alarm events. The sequenceis H1, H2, through H10, and INIT. To delete the alarm history, select INIT ,then press and hold the maintenance button for 3 seconds. (beep pattern:
short long short short)4) Press the maintenance button (one beep).
AL with history icon and the peak value
vol% during alarm of the selected alarm
event are alternately displayed.

History icon
(Ex. Alarm peak value is 18.0vol%)button cycles through the details of the selected alarm event. The
5) Each press of thesequence is: starting year, date, and time and ending year, date, and time of the event.

(Start of alarm)(Start of alarm)(Start of alarm)(End of alarm)(Year)(Month(End of alarm)Day)(Time)(End of alarm)- 21 -(Year)(MonthDay)(Time)

6) Press the RESET button (one beep) to display theselected alarm event number H * .
To display other alarm event, repeat Steps 3) to 5).
(Ex. H1 is selected)

To delete the alarm history, select INIT in Step 3),
then press and hold the maintenance button for 3
seconds (beep pattern: short long short short).
The deletion is complete.

7-4-7. Clock Setting [Mode 6]
Clock is used when recording the alarm history.
button to select1) Enter the User mode. Press the /6 (each press of the button is followed by one beep).
DATE and 6 will be alternately displayed.
2) Press the maintenance button (one beep). YEAR
and * * * * (year) will be alternately displayed.
button. The
3) Select the item to change with the /item and its currently set value will be displayed.
NOTE

Each press of the
button cycles through: YEAR , MON (month), DAY ,HOUR and MIN (minute).

When selecting YEAR , for example,
4) Press the maintenance button (one beep). The currently
set year will be displayed.
5) Change the set value by using the/(Ex. Year is currently
set to 2013)

button.

(Ex. Changed from 2013 to 2014)6) Press and hold the maintenance button for 3 seconds
to confirm the change (beep pattern: short long short
short). YEAR and the set year will be alternately
displayed.

(Confirmed)

7) To change the other items, repeat Steps 3) to 6).
8) Press and hold the RESET button for 5 seconds (twobeeps) to return to normal operation mode.
(Back to normal operation mode)- 22 -

7-5. Maker ModeAll the items set in the Maker mode (e.g., alarm set value) are password-protected.
WARNING
Incorrect settings in the Maker mode may change the detector s specifications. Never
operate in a way other than as described in this instruction manual.
Only a selected administrator should have the authority to make changes in the Maker
mode.
Gas detection is not possible during the Maker mode. To exit the Maker mode and return tonormal operation, power cycle the unit before use.

7-5-1. Maker Mode Activation
First, turn off the detector. Simultaneously press and hold down theandand POWER
buttons for 3 seconds (two beeps) to activate the Maker mode. The software version is displayedthen all the LCD segments turn on, and finally
starts flashing. Now the Maker mode is active.

MaintenancebuttonSoftware version isdisplayed

All LCD segments
turn on775 flashes< Maker Mode activates>

Main power switch

7-5-2. Operating Time RefreshThis detector is designed to notify when a sensor needs replacement (refer to 8-1.5) Sensor
Replacement Reset the operating time to zero after battery replacement.
1) Read 7-5. Maker Mode including the WARNING beforehand.
Enter the Maker mode. Now 775 is flashing.
2) Press the
button twice (two beeps) to change the password
from 775 to 777. Now 777 is flashing.

775 flashes

WARNING
Before moving
777
displayed. If this step is not taken, it may change
the detector s specifications.
777 flashes- 23 -

3) Press the maintenance button (one beep). 4mA will be
displayed.
NOTE

Use a rounded pin (e.g., precision
screwdriver)forpressingthemaintenance button.

4) Press the
button (one beep).
The total operating time will be displayed in hex notation.
WARNING
Before moving
total operatingtime must be displayed. If this step is not taken, it
may change the detector s specifications.
NOTE(Ex. Total operating time is 2239 or 1 year)

through the details of total operatingtime. The sequence is shown below.

Total operating time5) Press and hold the maintenance button for more than 3
seconds (beep pattern: short long short short).
The operating time will be reset to 0 .
NOTE

If the operating time refresh is not
successful, two beeps are heard and thevalue does not become 0 . In this case,press and hold the POWER button for 3
seconds to turn off the unit, then repeat theprocedure. If the unit still fails to refresh,
contact your New Cosmos representative
for repair.

(Total operating time is reset)

6) To end the refresh, press and hold the POWER button for
3 seconds to turn off the unit.

7-5-3. Alarm Set Value Change
1) Read 7-5. Maker Mode including the WARNING
beforehand. Enter the Maker mode. Now 775 is flashing
775 flashes

2) Press the maintenance button (one beep).
AL 1 will be displayed and the AL1 alarm LED will turn on.
NOTE

When the alarm stage displayed is theupper limit, its corresponding alarm light
flashes at a one-second interval.

- 24 -

1) Use thestage.
NOTE/

button (one beep) to select the alarm

Each press of the/
buttonalternates between AL 1 and AL 2 .
(1st stage alarm)(2nd stage alarm)

2) Press the maintenance button (one beep) to confirm theselection. The current alarm set value for the selectedalarm stage will be displayed.
(Ex. AL1 alarm set value
Is currently set to 19.0vol%)3) Change the alarm set value by using the/

button.

4) Press and hold the maintenance button for more than 3
seconds (beep pattern: short long short short) for
confirmation. The new alarm set value has been set andAL1 or AL2 is displayed.
NOTE

If the alarm set value change is not
successful, two beeps are heard and theprevious set value remains displayed. In
this case, press and hold the POWER
button for 3 seconds to turn off the unit,
then repeat the procedure. If the unit still
fails to change the alarm set value, contact
your New Cosmos representative forrepair.

5) To change another alarm set value, repeat Steps 3) to 6).
6) To end the procedure, press and hold the POWER button
for 3 seconds to turn off the unit.
7) Press and hold the POWER button for 3 seconds torestart the unit in normal operation mode. Check thealarm set values. (Refer to 7-3-3. Full Scale and Alarm
Set Value Display .)- 25 -(Ex. Changed to 19.5vol%)8. Maintenance
Daily checks are carried out by the user, while monthly and annual inspections are performed by theuser, New Cosmos or its authorized representative.

Important Notice for MaintenanceIn order to ensure the reliability of the gas detector, it is vital to perform periodic sensor
replacement. While it is possible for the user to perform the replacement, it is highly
recommended that a maintenance contract with a local New Cosmos representative bemade for the performance of scheduled sensor adjustment and replacement.

8-1. Inspection Contents and Frequency
Check items

Start-up

Expansion or
relocation

Periodic Inspection
Monthly

AnnualDaily check1) Concentration display2) Backup battery level*13) Alarm test4) 21.0 vol% adjustment *25) Sensor replacement*3*1. Regardless of the battery level, the first battery replacement should be done within 3 years fromthe purchase date. Succeeding replacements should be done every 3 years.
*2. Perform a 21.0vol% adjustment in clean air.
*3. The first sensor replacement should be done within 1 year from the purchase date. Succeeding
replacements should be done every year.
1) Concentration Display
Check that the oxygen concentration is displayed on the LCD and that the detector operates
properly.
2) Backup Battery Level
Check the backup battery level on the LCD. If the low battery icon
appears (indicating
70 hours or less of operation), then battery replacement is recommended.
The unit can continuously operate for about 350 hours with a new backup battery (at 20°C,
with no alarm activation and backlight being off).
NOTE

Backup powering is not possible while the empty battery alert iconisflashing. A low battery does not affect the detector s operation, but replace thebattery or remove it from the unit in order to prevent possible battery leakage.
If a gas alarm occurred while the backup battery was being used, a significant
amount of battery was consumed. Battery replacement is recommended.
Even though the backup battery was unused, replace it every 3 years to prevent
possible battery leakage. (Replace the clock battery every 10 years regardless of
its battery level.)
Refer to 8-2. Sensor/Backup Battery/Clock Battery Replacement for battery
replacement procedure.
- 26 -

3) Alarm Test
Check that an alarm activates correctly by referring to 7-4-5. Alarm Test .
CAUTION
Perform an alarm test in accordance with the applicable local laws and regulations. For
example, the applicable law in Japan specifies that alarm activation must be checked by
performing a circuit check once every month.
An alarm test activates the external relay contacts of the detector. If the detector s external
relay contacts are used to operate the interlocks, etc., of the external devices, release theinterlocks beforehand, as needed to prevent a possible activation of the interlocks. Notify
those concerned before starting an alarm test or inspection.
4) 21.0 vol% Adjustment
Check that the displayed concentration is 21.0% while in clean air. If not, perform a span
adjustment by referring to 7-4-4. Span Adjustment .
If the indication differs greatly from 21.0vol% or other error is found, the sensor needs to be
replaced.
NOTE

The output of a galvanic cell sensor is commensurate with oxygen partial pressurein the atmosphere. Therefore, the concentration indication may be affected by anatmospheric pressure change even though the oxygen concentration itself isunchanged.
CAUTION

Perform 21.0 vol% and span adjustments in clean air.
Proper gas detection is not possible if 21.0 vol% and span adjustments are incorrectly
performed.
5) Sensor Replacement
Even if the detector is unused for a long period of time, replace the sensor one year from thepurchase date. (Refer to 8-2. Sensor/Backup Battery/Clock Battery Replacement. )NOTEThis detector counts each hour while it is on. When the total operating time reaches
one year, sensor replacement alert will be notified by audio alarm and onscreen
indication. The audio alarm sounds at a one-minute interval. To mute the audio
alarm, press the RESET button. The muted audio alarm will become audible, oncethe detector is power cycled. To mute the resumed audio alarm, press the RESET
button.
* The sensor replacement alert is set to on by default when shipped out, and it can be muted
if specified. Please specify the mute option at the time of order, if necessary. Onscreen
sensor replacement alert is always set to on regardless of the audio setting.

CAUTION
Replace the oxygen sensor (Part No. OS-3M-K) with a new one once every year.
Install a new sensor into the detector before its shelf life expires. The shelf life is one year
from the production date indicated on the sensor package.
For sensor replacement, the detector needs to be turned off. When detector s outputs areused to control the interlocks,etc. of the external devices, release the interlocks as needed.
Perform a span adjustment of the newly installed oxygen sensor after more than 30
minutes from removing the sensor from its shipping package.
- 27 -

8-2. Sensor/Backup Battery/Clock Battery Replacement
CAUTIONUse a CR2 lithium battery, cylindrical type for backup battery.
Use a CR2032 lithium battery, coin type for clock battery.
1.
2.
3.
4.

Press and hold the POWER button for 3 seconds to turn off the detector.
Open the screw cover.
Loosen the two fastening screws (these screws cannot be fully removed).
2
3
Slightly pull the cover forward.
41

5. Slide the cover up by holding Part A (2 places, each side of the cover) until the middle alignment
markings on Part A and the alignment markings on Part B match.
6. Turn off the main power by setting the main power switch to the off (down) position.
5

CAUTION
Turn off the detector s main
power to avoid electric shocks.

6

O
Part B(2PL)

O
Part A(2PL)

7. Pull and detach the cover from the case by holding Part C (2 places, each side of the cover).
CAUTION Cover and case are connected with a connector cable.
Cover
Case

CAUTION
7. Lift

Part C(2PL)

Take care to prevent
breaking the connector
cable between the caseand the cover.
- 28 -

8. Temporarily hang the cover on the top of the case by engaging the cover s Part E into the case sPart D.
Top of the casePart ETop of the coverPart DEngaged8. Hang

Oxygen sensor

9. Remove backup battery
Leave more than 3 seconds
10. Replace sensor
11. Install backup battery
Clock battery
Backup battery

9. Remove the backup battery from the case. Wait more than 3 seconds before installing a newone.
CAUTION
Backup battery should be CR2, cylindrical cell not coin cell.
10. Replace the oxygen sensor with a new one.
CAUTION
Pinch the head of the oxygen sensor (plug-in type) and pull out horizontally to remove itfrom the printed circuit board.
Correctly install a battery by checking the polarity marking on the battery holder.

- 29 -

CAUTION
Horizontally install the oxygen sensor so that its connector pins are horizontally inserted into
the sensor socket s pin holes. Forced insertion from the side may damage the socket, which
will cause a poor connection.
Good

Sensor socket

Not good

OxygensensorPCB

Place the sensor in place so that its connector pins (+) (-) and the socket s pin holes (+) (-) on
the printed circuit board match, then gently push it into place.
(-) pin(-) socket pin hole(+) pin- +(+) socket pin
hole

CN6 CN3

Marking on PCB

Sensor outline
Sensor bottom (pins)

Sensor socket

11. Install a new backup battery (CR2, cylindrical) in the battery holder.
12. (Reverse Step 8) Pull and detach the case from the top of the case by holing the Part C (2places, each side of the cover). Align Part A to Part B (2 places, each side of the cover) toengage the cover into the case.
13. Turn on the main power by setting the main power switch to the on (up) position
14. (Reverse Step 5) By holding Part A (2 places, each side of the cover), match the middlealignment markings on Part A and the alignment markings on Part B, slide down and close thecover.
15. Press up and open the screw cover. Tighten the two fastening screws.
CAUTION
Secure the cover by tightening the two fastening screws. Proper gas detection is not possible
if the cover is not tightly closed.
16. Close the screw cover.
17. If the oxygen sensor is replaced, perform the following adjustments.
Perform a span adjustment. (Refer to 7-4-4. Span Adjustment )Reset the total operating time to zero. (Refer to 7-5-2. Operating Time Refresh )CAUTION
If the oxygen sensor is replaced, span adjustment is necessary. Proper gas detection is notpossible without a span adjustment. Sensor replacement notification will not be reset without
an operating time refresh.
- 30 -

9. Troubleshooting
Before requesting repair, please refer to the table below. If the detector does not return to normal
operation after performing the corresponding steps in the table, or if your issue is not found in the table,
consult New Cosmos or its authorized representative.
Problem

Probable cause

Solution

Reference section

Set the main power switch
Main power switch or

to on position or press and

POWER button is off

hold the POWER button for
3 seconds.

Green status indicator notlit

7-2. Operating Procedure

Incorrect wiring or loose

Check and

connection

rewire/reconnect.

No power supplied

Supply correct power.

Product is in Maintenance

Switch the Maintenance

7-4-2. Switchingmode

mode to OFF.

Maintenance Mode On/Off

Product is in Maintenance

Switch the Maintenance

7-4-2. Switchingmode

mode to OFF.

Maintenance Mode On/Off

Incorrect alarm set value

Check the alarm set value.

6. Wiring
7-1. Precaustions before
Use

Maintenance icon
displayed on LCD, andgas concentration value
andalternately

No audio alarm

None-audio unit selected attime of order

7-3-3. Full Scale and Alarm
Set Value Display

Consult your New Cosmos representative.

Product is in Maintenance

Switch the Maintenance

7-4-2. Switchingmode

mode to OFF.

Maintenance Mode On/Off

Incorrect wiring or loose

Check and

connection

rewire/reconnect.

Incorrect alarm set value

Check the alarm set value.

Detector operates on theThis is not a failure and the7-3-2. Normal Operation

backup battery

detector operates normally.

Status

6. Wiring

Alarm relay contacts do
not activate- 31 -

7-3-3. Full Scale and Alarm
Set Value Display

Problem

Probable cause

Solution

Reference section

Replace the sensor with a
new one.
Sensor replacement
icon displayed on LCD
Once a minute sensor
replacement audio
alarm

To mute the audio alarm,

8-1. 5) Sensor

Total operating time haspress he RESET button.

Replacement

reached one year, and the

The muted audio alarm will

sensor replacement alert is

become audible, once the8-2. Sensor/Backup

activated.

detector is power cycled.

Battery/Clock Battery

To mute the resumed audio

Replacement

alarm, press the RESET
button.
Press and hold the

Status indicator flashing

POWER button for 3

between green and red--

seconds to turn off the-detector. After a few

displayed on LCD
Audio alarm sounds

Internal error

Fault alarm relay contact

minutes, turn the detector
on again. If the product7-2. Operating Proceduredoes not return to normal

activates

operation, contact yourAnalog output is lower

New Cosmos

than 0.9 mA

representative for repair.
Press and hold the
POWER button for 3

Audio alarm sounds
Analog output is lower
than 0.9 mA

seconds to turn off theSensor error

detector. Turn on the(Incorrect zero adjustment

detector in clean air. If theor sensor abnormality)

product does not return to

7-2. Operating Procedurenormal operation, contact
your New Cosmos
representative for repair.
Replace the backup battery

Audio alarm sounds

Backup battery is empty

with a new one.

8-2. Sensor/Backup

Pressing the RESET button

Battery/Clock Battery

can mute the audio alarm

Replacementfor one hour.
Turn off the detector andremove the backup battery
from the unit, then reinstall.
Other than the above

Microcomputer may

Turn on the detector. If themalfunction due to noise.

product does not return tonormal operation, contact
your New Cosmos
representative for repair.

- 32 -

7-2. Operating Procedure
8-2. Sensor/Backup
Battery/Clock Battery
Replacement10. Specifications
Detection principle

Galvanic cell sensor

Sampling method
Target gas

Diffusion type
OxygenDetection range
Display

0-25.0vol% or 0-50.0vol%Four-digit LCD with backlight, resolution 0.1vol%

Alarm set value

F.S.25vol%: 19vol% (AL1, lower limit) and 18vol% (AL2, lower limit)
F.S.50vol%: 18vol% (AL1, lower limit ) and 25vol% (AL2, upper limit)

Indication accuracy *1
Alarm accuracy+/- 0.7vol% (when indication is 25vol% and lower)+/- 3.0vol% (when indication is 25.1vol% and higher)
Displayed value is equal to the alarm set value in the event of alarm

Alarm delay

Less than 5 seconds to reach 18vol% (alarm is triggered) after exposure
to 10vol% gas concentration at 20+/-2°C

Alarm

Gas alarm (in two stages)
1st stage gas alarm: AL1 alarm LED flashes (lit if the audio alarm ismuted), amber status indicator sequentially-flashes, audio alarmsounds, and AL1 icon is displayed on LCD.
2nd stage gas alarm: AL1 and AL2 alarm LEDs flash (lit if the audio
alarm is muted), red status indicator sequentially-flashes, audio alarmsounds, and AL1 and AL2 icons are displayed on LCD.
Alarm clearance method: Manual-resetting (standard) or self-resetting *3

External output *4

Explosion-proof
Compliance *5

Gas concentration analog output *2: 4-20mADC (common negative withpower supply) (Current sensing resistor musta wiring resistance)
Gas alarm relay contacts (in two stages): Dry NO (standard) or NC
contacts, manual-resetting (standard) or self-resetting *3(Max load: 0.5 A at 125 VAC or 2 A at 30 VDC (resistance load)
Fault alarm relay contact: Dry NO (standard) or NC contact,
manual-resetting (standard) or self-resetting *3(Max load: 0.5 A at 125 VAC or 2 A at 30 VDC (resistance load)
Not explosion-proof
EMC:2014/30/EU/SI 2016 No.1091
RoHS:2011/65/EU+(EU)2015/863/SI 2012 No.3032

Applicable cable

Maintenance mode used to disable gas alarm relay contacts, audio alarm
mute, and backup battery used in the event of power outage
0.5-1.25 mm2 shielded cable. Outer diameter: less than 10.5 mm

Cable length
Operating temperature andhumidity

Up to 500 m-10 to +40°C, 30 to 85%RH(No rapid temperature/humidity changes. No condensation)

Operating pressure

80 to 110 kPa

Power supply

24 VDC±10% or 100 VAC±10% 50/60 Hz±10%
24 VDC: 1 W during normal operation, 3W during alarm, or
100 VAC: 2 VA during normal operation, 6VA during alarm

Other features

Power consumption
Dimensions
Mass

W82 x H150 xD35 mm (excluding protruding parts)
Approx. 300 g

Mounting method

Wall mounting, indoors*1. Checked after gas calibration following a 30-minute warm-up cycle from powering-up.
*2. Output concentration value is within the detection range.
*3. Manual-resetting or self-resetting; NO (normally open) or NC (normally closed) are specified at the time of order.
*4. When the detector operates on the backup battery, the analog output is 0mA (no output) and the gas/fault alarm relay
contacts are all disabled.
*5. CE marking specification applies to KS- O(separate document) for information on the CE marking unit.

- 33 -

11. Warranty
The warranty period is one (1) year from the date of purchase.
You are entitled to the limited warranty, if the product malfunctions due to a manufacturing defectduring normal use in accordance with the instruction manual, specifications and labels.
Warranty Scope
If the product fails or is found to be damaged due to a manufacturing defect during the warranty period,
and used in accordance with the instruction manual and specifications, we will provide a freereplacement or repair service. This warranty covers the New Cosmos product/parts only and not third
party product/parts.
Warranty Exclusions
The following will be repaired at the cost of customer even during the warranty period.
(1) Failures and damages incurred by incorrect use, deliberate acts or negligence of the user.
(2) Failures and damages caused by disaster, earthquake, storm and flood, lightning, extreme climate,abnormal power supply voltage, excessive electromagnetic interferences, or other acts of God.
(3) Failures and damages resulting from repair and/or modification by non-New Cosmos certified
technicians.
(4) Consumables and failures and damages resulting from improper consumable replacement.
(5) Other failures and damages not attributable to the manufacturer.

12. Expected Sensor LifeThe estimated service life of the sensor is shown in the table below. The sensor may fail to provide
correct detection after its service life expires. Replace the sensor before its expiration. This
expected service life assumes that maintenance is done properly and periodically and that thesensor is not exposed to high concentration gas or gas that may cause sensor poisoning. This does
not imply that the sensor will provide correct detection values up to the end of the service life. Thus,
no warranty will be given after the one-year period is over.
Detection principle

Expected sensor life

Galvanic cell sensor

1 year- 34 -

13. Detection Principle
Galvanic Cell Sensor
The sensor consists of two electrodes, a membrane and an electrolyte. To accelerate reactions of gas in
the atmosphere on the electrodes, the membrane is designed to adhere tightly to the electrodes.
The electrodes are two different metals, noble metal (Pt, Ag) and base metal (Pb). The noble metalelectrode has contact with air via a Teflon membrane. Connecting load resistance to both electrodes
generates a potential difference, which speeds up the following reactions:
Noble metal electrode: O2 + 2H2O + 4e
Base metal electrode: 2Pb
2Pb2+ + 4e

Thermistor

4OH

As a result, the current proportional to the oxygen
concentration in the air flows from the noble metal electrodeto the base metal electrode via the external circuit. Since theelectromotive force changes depending on the temperature,a thermistor is added to compensate for the ambient
temperature variations.

- 35 -

OutputO2 sensor
Resistor

14. Glossary
TermDefinition

Clean air or
normal air

Standard atmosphere which contains 20.9 to 21.0% oxygen in dry condition or
atmosphere without target gas or interference gases.

Gas detector

Device used to detect the presence of a target gas and to give its concentration in
the form of an electrical signal.

Diffusion type

Sampling method using convective diffusion while placing a gas detector at a
detection point.

Target gas

Specific gas to be detected, concentration displayed, and used to trigger alarms.

Detection range

A range of target gas concentrations that can be displayed and trigger alarms.

Service range

A range of target gas concentrations the detector is able to indicate, which areusually outside the Detection Range and used only as reference.

Alarm set value

Preset gas concentration level at which an alarm is triggered.

Alarm accuracy

Difference between the alarm set value and gas concentration value at which an
alarm is actually triggered, or percentage of the difference compared to the alarm
set value.

Alarm delay

Time required for an alarm to trigger after the detector is exposed to a gas
concentration level, higher or lower than the alarm set value.

Operatingtemperature andhumidity ranges

Ambient temperature and humidity ranges in which the gas detection and alarmsystem can operate normally.

Maintenance andinspection

Tasks performed to ensure that equipment operates normally and correctly.

Self-resetting

Gas alarm clearance method. When the gas concentration falls below (or above
when the alarm set value is the lower limit) the gas alarm set value after an alarm
has been signaled, relevant alarm lights, gas alarm icon and alarm relay contacts
will automatically return to their normal positions/statuses.

Manual-resetting

Gas alarm clearance method. Even if the gas concentration falls below (or above
when the alarm set value is the lower limit) the gas alarm set value after an alarm
has been signaled, relevant alarm lights, gas alarm icon, and alarm relay contacts
will not automatically return to their normal positions/statuses. Manual operationis only possible when the gas concentration is below (or above) the gas alarm set
value.

Hazardous area

An area in which an explosive atmosphere is present, or may be expected to bepresent, in quantities such as to require special precautions for the construction,
installation and use of electrical apparatus.

Explosive
atmosphere

Mixture of air and flammable substances in the form of dust or vapor which arewithin their explosive limits.

Sequentially-flash

There are several LEDs inside the status indicator. In the event of a gas alarm,
one LED lights at a time and the lit LED moves from left to right.
- 36 -

15. Proper Product Disposal at End of Life
The Waste Electrical and Electronic Equipment WEEE directive 2012/19/EU
is intended to promote recycling of electrical and electronic equipment and theircomponents at end of life. This symbol crossed-out wheeled bin indicatesseparate collection of waste electrical and electronic equipment in the EU countries.
This product contain two Lithium batteries. Specific battery information is given inthis instruction manual. Batteries must be recycled or disposed of properly.
At the end of its life, this product must undergo separate collection and recyclingfrom general or household waste. Please use the return and collection system
available in your country for the disposal of this product.

- 37 -

Document No.
GAE-052-00
GAE-052-01
GAE-052-02
GAE-052-03
GAE-052-04
GAE-052-05
GAE-052-06

Revision History
Date
June 2014
May 2016
October 2018
June 2019
December 2020
September 2022
June 2023

Revision
0
1
2
3
4
5
6

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

Authorized representative:

Manufacturer:
NEW COSMOS ELECTRIC CO., LTD.
2-5-4 Mitsuya-naka, Yodogawa-ku,
Osaka 532-0036, Japan
www.newcosmos-global.com