ANALOX CO Clear User manual

Analox Ltd.
15 Ellerbeck Court, Stokesley Business Park
North Yorkshire, TS9 5PT, UK
T: [phone] F: [phone]
W: www.analox.net E: [e-mail]
CO Clear
User Manual
Commercial in Confidence

CO Clear
User Manual Int. Approved
Document ref: ACO-810-28 October 2018 Page 3 of 24
Copyright © 2006 Analox Ltd. All Rights Reserved.
Commercial in Confidence
Table of Contents
1Safety information ........................................................... 4
1.1 Electrochemical sensors (Carbon monoxide) .......................................... 4
1.2 Fuse ratings ............................................................................................ 5
1.3 Other information ................................................................................... 5
2Package contents checklist .............................................. 6
3About the product............................................................ 7
4Sensor characteristics and helium effect ......................... 8
5Installation of the product ............................................... 9
5.1 Wall mounting ........................................................................................ 9
5.2 Wiring installation .................................................................................. 9
6Option available............................................................. 10
6.1 AC supply models.................................................................................. 10
6.2 DC supply models ................................................................................. 10
6.3 Alarm repeaters .................................................................................... 10
6.4 Alarm relay output models.................................................................... 10
6.5 Relay wiring.......................................................................................... 11
6.6 4 to 20mA output models...................................................................... 12
7Operation....................................................................... 13
7.1 Normal operation .................................................................................. 13
7.2 Alarm indications .................................................................................. 13
8Compressor connection ................................................. 14
9Maintenance .................................................................. 15
9.1 Recommended calibration interval........................................................ 15
9.2 Carbon Monoxide sensor replacement .................................................. 15
10 Calibration................................................................... 17
10.1 0 to 10ppm in nitrogen range calibration gases.................................... 17
10.2 0 to 25ppm in nitrogen range calibration gases.................................... 17
10.3 Zero calibration..................................................................................... 18
10.4 Span calibration.................................................................................... 19
10.5 Alarm check .......................................................................................... 19
10.6 Adjusting alarm set points .................................................................... 20
11 Fault conditions........................................................... 21
12 Specifications .............................................................. 22
13 Disposal....................................................................... 23
14 Declaration of conformity ............................................ 24

CO Clear
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1Safety information
1.1 Electrochemical sensors (Carbon monoxide)
Electrochemical sensors contain toxic compounds. Under normal conditions the sensor will
be safely sealed. To prevent leakage, the unit must not be exposed to temperatures
outside the specified range, or be exposed to organic vapours, which may cause physical
damage to the body of the sensor. The unit must not be stored in areas containing organic
solvents or in flammable liquid stores.
When the life of the sensor has expired, or it is leaking or otherwise damaged it must be
disposed of safely in accordance with local regulations.
Carbon monoxide cell contains an acidic electrolyte (sulphuric acid). In the event of an
accident, use the following first aid procedures.
Table 1 Electrochemical sensor first aid procedures
Body
Part
Effect
First Aid Procedures
Skin
Contact could result in a chemical burn.
Persons with pre-existing skin disorders
may be more susceptible to the effects
of the substance.
Immediately flush the skin thoroughly
with water for at least 15 minutes.
Remove contaminated clothing and wash
before re-use.
Obtain medical advice if continued
irritation.
Ingestion
Corrosive. May cause sore throat,
abdominal pain, nausea, and severe
burns of the mouth, throat, and
stomach, and may be fatal.
If swallowed DO NOT INDUCE VOMITING.
Wash out mouth thoroughly with water
and give plenty of water to drink.
Obtain medical advice immediately
Eye
Persons with pre-existing eye problems
may be more susceptible to the effects
of the substance.
Corrosive. May cause redness, pain,
blurred vision, and eye burns.
Contact can result in the permanent loss
of sight.
Irrigate thoroughly with water for at least
15 minutes.
Obtain medical advice immediately.
Inhalation
Persons with pre-existing impaired
respiratory function may be more
susceptible to the effects of the
substance.
Inhalation is not an expected hazard
unless heated to high temperatures.
Mist or vapour inhalation can cause
irritation to the nose, throat, and upper
respiratory tract.
Remove to fresh air.
Rest and keep warm.
Obtain medical advice if applicable.
Should leakage of any electrolyte occur as a result of misuse, incorrect operation,
manufacturing error, physical damage, etc. then wear protective gloves when cleaning any
spills. Should electrolyte contact skin then the affected area should be washed thoroughly
with copious water and medical advice sought if there has been any contact with the eyes
or mouth. If connected to any electrical equipment, the sensor should be immediately
removed.

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The Analox CO Clear is designed to be compliant with the following standards: EN61010-1:
2001, IEC61010-1: 2001, CAN/CSA-C22.2 No. 61010-1 Second Edition 2004, ANSI/UL
61010-1 Second Edition 2005. It is designed to be safe at least under the following
conditions.
•Indoor use
•Altitude up to 2000m
•Temperature -5°C to +40°C
•Maximum relative humidity 80% for temperatures up to 31°C decreasing linearly
to 50% relative humidity at 40°C.
•Mains voltage supply fluctuations not to exceed 10% of the nominal voltage
•Impulse withstand (over-voltage) category II of IEC 60364-4-443
•Pollution degree 2
•Mains voltage: -
230V AC (Not Adjustable - Instrument will be factory set)
110V AC (Not Adjustable - Instrument will be factory set)
24V DC (Not Adjustable - Instrument will be factory set)
•Mains power: -
Less than 5VA –110V AC and 230V AC Versions
Less than 5W –24V DC Version.
•Mains frequency - 50/60Hz
•The Remote Alarm Repeater has ingress protection to IP43: direct sprays of water
up to 60° from the vertical in accordance with EN 60529:1991 + A1. All other
units have ingress protection to IP65: low pressure water jets from all directions
and totally protected from dust in accordance with EN 60529:1991 + A1.
•Insulation: - Reinforced insulation, class II product according to IEC536.
•Not for use in corrosive or explosive atmospheres
•Not approved for use in vehicles, ships or aircraft
1.2 Fuse ratings
Table 2 Fuse ratings
230V AC, 500mA
F rating 250V (20mm x 5mm Glass Cartridge)
110V AC, 500mA
F rating 250V (20mm x 5mm Glass Cartridge)
9-24V DC, 200mA
AS rating 250V (20mm x 5mm Glass Cartridge)
1.3 Other information
Battery Back-Up
The Battery Back-Up is non-repairable. Please return faulty units to Analox for
refurbishment or replacement.
4 to 20mA (or 0-1V) Output
Connected equipment must meet the requirements for reinforced insulation.
NOTE:
IF THE EQUIPMENT IS USED IN A MANNER NOT
SPECIFIED BY THE MANUFACTURER, THE PROTECTION
PROVIDED BY THE EQUIPMENT MAY BE IMPAIRED.

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2Package contents checklist
On receipt of the Analox CO Clear please check you have the following:
1) Analox CO Clear main unit and Alarm Repeater
2) User Manual
3) Test Certificate
4) Rawl Plugs and Screws for Wall Mounting
5) Drilling Template
6) Analox CO Clear Window Sticker
7) Analox CO Clear wall notice
Any optional items ordered such as:
1) Battery back-up
2) Relay junction box
3) Additional 6mm Push-fit connector
4) Additional ¼ inch Push-fit connector
5) 6mm tubing
6) ¼ inch tubing

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3About the product
Two variants of the Analox CO Clear are available.
The Analox CO Clear is designed to detect the presence of Carbon Monoxide in air or Nitrox
gas compressors.
The Analox CO Clear He is designed to detect the presence of Carbon Monoxide in Heliox
(HeO2) gas compressors. This variant can be identified by the serial number label as
shown below.
Different versions of the instrument allow operation from:
1) 210/250V AC supply
2) 110/120V AC supply
3) 9-24V DC supply
The Analox CO Clear is intended to be used as a permanent installation. It provides a
digital readout of Carbon Monoxide and 2 audio and visual alarms to warn you of elevated
levels of Carbon Monoxide. The alarms are set with a small hysteresis (0.5ppm) which
means the CO concentration must fall below the alarm set point before the alarm cancels.
The instrument uses an Electrochemical cell together with state-of-the-art technology, built
in an IP65 splash proof housing and is designed to provide long, trouble free service, with
minimum maintenance.
Optional items fitted to or supplied with the unit may include the following:
1) One or two medium duty relays
2) Test Gas and control valve
3) Battery Back-Up
4) 4-20mA output

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4Sensor characteristics and helium effect
The carbon monoxide cell is a capillary type sensor. These types of sensors are affected by
the presence of Helium (He), and in such cases give higher than anticipated outputs. For
this reason, the Analox CO Clear He has been developed for use in Heliox gas applications
(e.g. Saturation diving).
For a detailed explanation of what the helium effect is and how it affects the
measurements of carbon monoxide please refer to document ACO-MISC01-00 Helium
sensitivity effect available from Analox.
The basic effect of He in the sample gas is to increase the carbon monoxide sensitivity.
This means that as the amount of He increases the sensitivity of the CO cell increases by
what we call the ‘compensation factor’ (see Table 1).
For example, if a CO Clear He measured 3ppm CO in a tank containing 99% He, the actual
CO content would be 2.1ppm (3 x 0.7 = 2.1ppm).
The look-up table below Table 3 shows a simplified representation of the helium effect to
quickly identify the compensation factor to be applied to your gas measurement.
NOTE:
THE COMPENSATION FACTORS IN TABLE 1 ARE BASED
ON A CO CLEAR HE CALIBRATED WITH A MIX
CONTAINING 79% HE BALANCE AS PROVIDE IN THE
CO CLEAR HE CALIBRATION KIT (SEE CALIBRATION
SECTION FOR DETAILS).
Table 3 Helium effect compensation factors
% Helium
in mix
Compensation
factor
79 to 83
1.0
83 to 89
0.9
89 to 94
0.8
94 to 99
0.7
The helium effect increases as the He content in the sample gas increases, so it is
important that the correct calibration gases are used. For this reason, the instrument
MUST be calibrated using 21% O2 in He balance calibration gas (see Calibration section
for details). This ensures that any measurement errors due to the helium effect are fail-
safe.

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5Installation of the product
5.1 Wall mounting
The Analox CO Clear should be mounted onto a wall or vertical flat surface using the
mounting lugs; a paper drilling template is supplied in the packaging. Use the paper
template to drill the 4 required holes in the wall and use the Rawl plugs and screws
provided to mount the unit. It is not necessary to dismantle the Analox CO Clear main unit
in any way prior to installation. You need to ensure the mains plug, fused at 3 amps is in
easy reach of a power socket.
The Alarm Repeater housing also has wall mounting lugs.
5.2 Wiring installation
It is necessary to identify the model of Analox CO Clear prior to installation. The
Calibration Certificate accompanying each instrument will clearly identify the information
required.
WARNING:
ENSURE THAT THE ELECTRICAL SUPPLY TO THE
INSTRUMENT IS SWITCHED OFF PRIOR TO
INSTALLING ANY WIRING.

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6Option available
6.1 AC supply models
A mains powered Analox CO Clear is pre-wired with a mains cable, fitted with a plug suited
to the destination country. Where internal plug fuses are fitted, these are 3 Amp. Ensure
that the unit is connected to the correct supply voltage (i.e. 110 or 230V AC). Where no
fuse is fitted in the plug, the instrument should be powered from a 3 Amp fused outlet.
The Analox CO Clear is fitted with an internal fuse, which is rated at 500mA.
6.2 DC supply models
A DC powered Analox CO Clear require a DC supply in the range 9-24V DC. A 2m cable is
factory fitted to the instrument. The DC supply should be connected to this cable as
follows:
1. Blue wire negative (0Volts)
2. Red wire positive (+9-24Volts)
6.3 Alarm repeaters
The Alarm Repeater has four status indicators and a Mode button, which mimic the button
and indicators on the main Analox CO Clear enclosure.
An 8 metre, 8 core cable is pre-wired to the Analox CO Clear on units to be fitted with an
alarm repeater. This ensures that for a basic installation, there is no need to dismantle the
Analox CO Clear main unit. A maximum of three repeaters may be fitted in a daisy chain
configuration.
To connect and disconnect a “Quick Connect” Repeater:
Disconnect the power supply from the Analox CO Clear.
Insert the connector on the end of the cable into the socket on the base of
the Alarm Repeater.
Restore power to the Analox CO Clear. Press the mode button on the
repeater once and ensure that the four indicators flash. Note that in the
presence of a genuine alarm, the test feature is disabled.
6.4 Alarm relay output models
You may have ordered your Analox CO Clear with a relay. The relay contacts are ‘Volt-
Free’ single pole Changeover, rated 250vAC/30vDC 2 Amps. The relay is non-latching. This
means the relay will only initiate when gas is present. As standard the relays are setup in
a Fail-Safe configuration. This means that the relay is energised during normal operation.
Please note that on power up the relay is only energised after the 40 second warm-up
period. See Figure 1 for details of how the relay should be connected.

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6.5 Relay wiring
The cable gland is for cables of outside diameter between 5 and 7mm, if cable fitted is
outside that range, a suitably specified cable gland must be used. Ensure that the gland is
properly tightened. Test that the cable is adequately gripped by the cable gland. Ensure
that the cable is suitable for purpose, the load is within the limits of the relay,
240VAC/28VDC, 2Amps, and the insulation of the external circuit meets the requirements
for basic insulation 240VAC/28VDC, 2 Amps. After completing wiring, ensure that the
terminal box cover is securely replaced.
Figure 1 Relay terminal box terminations
Figure 2 –Relay Connections
Once the Analox CO Clear installation has been completed a calibration should be
performed in accordance with section 10 of this manual.

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6.6 4 to 20mA output models
You may have ordered your Analox CO Clear with a 4 to 20mA output. A 2m cable is
factory fitted to the instrument. The 4 to 20mA output current is generated by the
instrument. The customer system should be connected to this cable as follows and as per
the following drawing:
1) Blue wire 4 to 20mA negative
2) Red wire 4 to 20mA positive
(Max load 150 Ω)

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7Operation
7.1 Normal operation
When the Analox CO Clear is turned on it will take approximately 40 seconds to warm up
and stabilise. During this period, the 'Good/OK' and 'Fault' status indicators will be turned
on. After the initial stabilising period has expired, the 'Fault' status indicator will turn off.
The 'Good/OK' status indicator will be illuminated and flash off briefly every few seconds,
indicating normal operation. The status indicators on any Alarm Repeaters will mimic this
operation. On display models the display will briefly read ‘.8.8.8.8’ on power up before
reverting to the CO reading.
7.2 Alarm indications
If the Analox CO Clear detects a CO concentration which is greater than the first alarm
level, then the 'Alarm 1' indicator will begin to flash and the buzzer will sound at its slow
speed.
If the measured concentration of CO continues to rise above the second alarm level, then
the ‘Alarm 2' indicator will begin to flash, and the buzzer will sound at its medium speed.
The 'Alarm 1' indicator will continue to flash.
On standard units the alarms are self-cancelling when the CO level drops below the alarm
limits.
Momentarily pressing the 'Mode' button on either the Analox CO Clear or any Alarm
Repeaters, in the absence of any alarm conditions, causes an alarm test to be performed.
The indicator lamps will flash 4 times and the buzzer will sound.
In all circumstances the Alarm repeater will mimic the status indications and buzzer of the
main unit.
Units fitted with relays are configured such that relays may operate in conjunction with
Alarm1 or Alarm2. They are factory set to be energised in the absence of alarms, and de-
energised in the presence of alarms. They may be factory configured in the opposite sense
if required.

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8Compressor connection
Connection of the Analox CO Clear to the compressor will require a pressure regulator. The
pressure regulator must fit the following specifications:
•Maximum inlet pressure 200Bar
•Outlet pressure 0-3 BarG
For systems where 1/4" pipe work is used the push fitting in the sensor housing must be
swapped out.
Remove the sensor housing and carefully remove the 6mm push fitting and replace with
the provided 1/4" push fitting and tighten, replace the sensor housing into the bulkhead.
To ensure trouble free operation of the CO Clear a 2-stage pressure regulation should be
used. The output of the selected regulator should be set a 2 bar

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9Maintenance
9.1 Recommended calibration interval
The Analox CO Clear should be calibrated on a regular basis to maintain measurement
accuracy. It is recommended that a calibration should be performed every six months.
9.2 Carbon Monoxide sensor replacement
The Carbon Monoxide sensor is mounted in a special housing on the under-side of the
Analox CO Clear enclosure. This housing allows the Carbon Monoxide sensor to be easily
replaced when necessary. To ensure continuous operation it is recommended to replace
the sensor at 18-month intervals.
The procedure for replacing the cell is as follows:
CAUTION:
DO NOT PULL ON HOSE CONNECTION TO REMOVE THE
SENSOR. USE A FLAT BLADE SCREW DRIVER AS
DESCRIBED BELOW.
Switch off the instrument
Use a large flat blade screw driver to release the sensor housing. This is
done by inserting the blade into the recess under the flange of the housing
and twisting the screwdriver.
The top of the Carbon Monoxide sensor will now be visible. Gently pull the
sensor housing downwards to release it from the bulkhead. It will be
retained by an electrical connector.

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Carefully pull the electrical connector from the rear of the Carbon
Monoxide sensor.
Fit the new Carbon Monoxide sensor to the connector, note it will only
connect in one orientation.
NOTE:
THE NEW CARBON MONOXIDE SENSOR IS SUPPLIED IN
A HOUSING, READY TO BE FITTED.
Carefully feed the sensor wire and sensor housing through into the
bulkhead and then firmly push the housing into the Bulkhead on the
under-side of the Analox CO Clear enclosure.
Switch the instrument back on.
Allow the sensor to settle for 1 hour.
Perform a Zero and Span Calibration Check to calibrate the new sensor.
Test the operation of the Carbon Monoxide alarms (see Alarm Check
section).

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10 Calibration
The Analox CO Clear should be calibrated on a regular basis to maintain measurement
accuracy. It is recommended that a calibration should be performed every six months.
All calibration gases should be sourced locally, calibration gases change depending on the
variant, calibration gases are listed below.
In order to perform a calibration check, you will need the following equipment:
10.1 0 to 10ppm in nitrogen range calibration gases
Air and Nitrox Kit (for use with Analox CO Clear)
1) Zero Gas, 20.9% O2 in N2 balance
2) Span Gas, 10ppm CO/20.9% O2 in N2 balance
3) Control valve
0 To 10ppm in helium range calibration gases
Heliox Kit (for use with Analox CO Clear He)
1) Zero Gas, 20.9% O2 in He balance
2) Span Gas, 10ppm CO/20.9% O2 in He balance
3) Control valve
10.2 0 to 25ppm in nitrogen range calibration gases
Air and Nitrox Kit (for use with Analox CO Clear)
1) Zero Gas, 20.9% O2 in N2 balance
2) Span Gas, 20ppm CO/20.9% O2 in N2 balance
3) Control valve
Connecting of the gas cylinder Correct flow rate

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10.3 Zero calibration
NOTE:
WHEN SETTING THE GAS FLOW RATE ON THE
CONTROL VALVE, SO LONG AS THE FLOW
INDICATION BALL IS RAISED OFF THE BOTTOM OF
THE GAS FLOW INDICATOR THIS IS SUFFICIENT
FLOW TO CALIBRATE THE INSTRUMENT ACCURATELY.
Fit the control valve to the zero gas.
Push the calibration valve pipe fully into the push-fit connector of the
sensor housing of the unit.
Fully open the control valve by turning the control knob anti-clockwise.
Allow the gas to flow for 2 minutes.
Enter Technician Mode by pressing the mode switch 3 times. If entered
successfully the green LED will flash off for 1.5 seconds and on for 0.5 of a
second.
Select Zero Calibration by pressing the mode switch 5 times. The Red
Alarm 1 LED will light up to show you are now in this mode.
Press the mode switch 2 times to start the Zero Calibration, the Red Alarm
1 LED will turn off and the Green LED will continue to flash.
Wait one minute for the instrument to adjust. When the instrument has a
new calibration value, the buzzer will sound one bleep and all the LED’s
will be off.
Accept this new calibration value by pressing the mode switch 2 times.
The green LED will flash to show the instrument has accepted the new
Carbon Monoxide value.
To return to normal operation, press the mode switch once. The LED’s and
buzzer will illuminate / sound 4 times before returning to normal
operation.
Fully close the control valve by turning the control knob clockwise.
Remove the calibration valve pipe from the elbow push-fit connector of
the sensor housing of the unit.
NOTE:
IF AT ANY TIME YOU WOULD LIKE TO ABORT ZERO
CALIBRATION, PRESS THE MODE SWITCH ONCE AFTER
STEP 9), THIS WILL BRING YOU BACK TO TECHNICIAN
MODE WITHOUT ACCEPTING THE NEW CARBON
MONOXIDE VALUE. PRESS THE MODE SWITCH ONCE
AGAIN, THIS WILL BRING YOU BACK TO NORMAL
OPERATION, THE LED’S AND BUZZER WILL
ILLUMINATE / SOUND 4 TIMES. ALTERNATIVELY,
DISCONNECT THE POWER SUPPLY TO THE ANALOX CO
CLEAR, WAIT A MOMENT AND RE-CONNECT POWER.

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10.4 Span calibration
Fit the control valve to the span gas.
Push the calibration valve pipe fully into the elbow push-fit connector of
the sensor housing of the unit.
Fully open the control valve by turning the control knob anti-clockwise.
Allow the gas to flow for 2 minutes.
Enter Technician Mode by pressing the mode switch 3 times. If entered
successfully the green LED will flash off for 1.5 seconds and on for 0.5 of a
second.
Select Span Calibration by pressing the mode switch 4 times. The Red
Alarm 2 LED will light up to show you are now in this mode.
Press the mode switch 2 times to start the Span Calibration, the Red
Alarm LED will turn off and the Green LED will continue to flash.
Wait one minute for the instrument to adjust. When the instrument has a
new calibration value, the buzzer will sound one bleep and all the LED’s
will be off.
Accept this new calibration value by pressing the mode switch 2 times.
The green LED will flash to show the instrument has accepted the new
Carbon Monoxide value.
To return to normal operation, press the mode switch once. The LED’s and
buzzer will illuminate / sound 4 times before returning to normal
operation.
Fully close the control valve by turning the control knob clockwise.
Remove the calibration valve pipe from the elbow push-fit connector of
the sensor housing of the unit.
10.5 Alarm check
To verify that the indicators and the audible alarms are working, press the Mode switch
on the Analox CO Clear. The indicators and the audible alarm will pulse four times.
To verify that the alarm levels are correctly set, you will need the following equipment:
1) Test Gas cylinder containing 10ppm Carbon Monoxide, 21% Oxygen in the
appropriate balance gas for that particular instrument
2) Control valve
Then follow the procedure below:
Fit the control valve to the test gas cylinder.
Push the calibration valve pipe fully into the elbow push-fit connector of
the sensor housing of the unit.
Fully open the control valve by turning the control knob anti-clockwise.
After a short time the 'Alarm 1' alarm should operate.
After further period of time the ‘Alarm 2’ alarm should operate.
Fully close the control valve by turning the control knob clockwise.
Remove the calibration valve pipe from the elbow push-fit connector of
the sensor housing of the unit.

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10.6 Adjusting alarm set points
The following procedure is very similar for setting either Alarm 1 or Alarm 2:
Whilst the Analox CO Clear is switched on, enter Technician Mode by
pressing the mode switch 3 times. If entered successfully the green LED
will flash off for 1.5 seconds and on for 0.5 of a second.
From Technician Mode, press the Mode switch 2 times to set Alarm 1 or 3
times to set Alarm 2. The buzzer will bleep on each press. If this is done
successfully, the instrument will show the Fault indicator and the
appropriate Alarm indicator. If this is done inadvertently, or if another
mode is selected, press the Mode switch once to return to Technician
Mode and then repeat this selection.
The display will indicate the present value of the alarm.
Press the Mode switch twice to proceed to define a new setting, or once to
abort and return to Technician Mode.
When setting Alarm 1 or Alarm 2, the display will show the maximum
display value (full scale).
Press and hold the Mode switch. The displayed value will count down at
approximately one count per second. Release the switch when the
displayed value is equal to the desired alarm value.
Upon release of the Mode switch, the display will continue to show the
new value. Accept the new setting by pressing the Mode switch twice, or
alternatively ignore the new setting by pressing the switch once. This will
return to the Technician Mode.
To exit from Technician Mode, press the Mode switch once. The Analox CO
Clear then restarts by performing the normal power on sequence (4
flashes).