CEM CO-181 User manual

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Carbon Monoxide Meter
Instruction Sheet

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1. Introduction
The Carbon Monoxide Meter detects the presence of carbon
monoxide
(CO) and measures concentrations between 1-1000 parts
per million (PPM).
The Meter indicates the presence of carbon monoxide in two
ways:
·By a reading on the LCD in PPM.
·By a beeper tone.
2. Safety Information-Read First
·Do not use the Meter as a personal safety monitor.
·Learn and recognize the effects of CO poisoning.
0-1PPM
Normal background levels.
9 PPM
ASHRAE Standard 62-1989 for living areas.
50 PPM
OSHAenclosed space 8-hour average level. *
100 PPM
OSHA exposure limit. *
200 PPM
Mild headache, fatigue, nausea and
dizziness.
800 PPM
Dizziness, nausea and convulsions.
Death within 2 to 3 hours.
*U.S. Department of Labor, Occupational Safety & Health
Administration (OSHA) Regulation 1917.24: The CO
content in any enclosed space shall be maintained at not
more than 50 PPM (0.005%). Remove employees from
enclosed space if the CO concentration exceeds 100 PPM
(0.01%).

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3. What the Meter Does
The Meter indicates the presence of CO by a reading on the
LCD and a beeper tone.
The beeper functions much like clicking of a Geiger counter:
·Above 200 PPM, the beeper sounds continuously with the
concentration of CO.
·From 35 PPM to 200 PPM, the beeper sounds
discontinuously with the Concentration of CO.
4. Specifications
Temperature
Operating:
Storage:
0℃to + 50℃
-30℃to + 60℃
Operating humidity
0-99% Relative humidity
(non-condensing)
Measurement range
0 to 1000PPM
Measurement
Resolution
1PPM
Accuracy
±5% or ±10 PPM
Warm up period
<2 seconds
Battery
9V, NEDA 1604A or IEC
6LR61, or equivalent.
Auto power off
Meter automatically shuts
down after 15 minutes of
inactivity
Sensor type
Stabilized electrochemical
Gas-specific (CO)
Typical sensor life
3 years

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Instrument Familiarization:
①CO sensor
②LCD Display
③MODE button
④Alarm light
⑤Power button
⑥SEL button
⑦Battery door
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6. MODE Button Functions
With operation of MODE button, you can read maximum
data, recall data, storage data, recall alarm, display
measuring time and set alarm. Each time you press
MODE, you will forward one step in the mode cycle.
①Measure mode
In this mode the meter measures the dynamic data, and
the LCD displays ‘CO’, ‘ppm’ and data. Keep pressing
SEL button over four seconds, you can turn on / off the
backlight. Press MODE button to enter maximum data
mode
②Maximum data mode
In this mode, LCD displays the max. data of this
measurement. When turn off the meter, the maximum
data will be cleared.
③Recall data mode
In this mode, LCD displays the stored data. Press SEL
button can recall next stored data.
This meter has up to ten locations for storing data. The
data on the top right corner of the LCD show you the

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memory position. Press MODE button to enter next
mode.
④Store data mode
You can store the measuring data by pressing SEL
button in this mode. The position of the storage is
displayed on the top right corner of LCD. After you
stored data, the number of the memory will increase
accordingly. You can select the position of storage data
by pressing SEL button
⑤Recall alarm mode
Press MODE button again to enter this mode, the LCD
displays the alarm data---30ppm. When the measuring
data is more than 30ppm and less than 200ppm, the meter
will warn with discontinuity beeper; when the measuring
datum is over 200ppm, the unit will warn with continuity
beeper. In both cases, the alarm light glows with red
light.
Keep pressing SEL button over eight seconds you can
enter the manual zero adjusting state. The data in the

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middle of LCD will firstly with flicker then turn into zero
and enter into the measure mode.
Measure
mode
Maximum
data mode
Recall data
mode
Store data
mode
Recall alarm
mode
Measuring
Time mode
Set alarm

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⑥Measuring time mode
Entering this mode, you can read the measuring time
on the LCD. It will be cleared after you turn off the unit.
The unit will disable auto power off function in this
mode. While in other modes, the meter will enable auto
power off after about 15 minutes without pressing any
button.
⑦Set alarm
In this mode, you can turn on / off the buzzer by
pressing SEL button. At the same time, LCD displays
‘on’ or ‘off’. When LCD displays ‘on’, the buzzer will
enable. Otherwise the buzzer will disable, but the alarm
light will enable.

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POWER BUTTON
I. Press the power button, power is on and the meter can
measure.
II. Press it again, Power is off.
BATTERY REPLACEME
I. As battery power is not sufficient, LCD will display
“ ” replacement with one battery type 9V is
required.
II. Open battery cover, then take out the battery from
instrument and replace with a new 9-Volt battery and
place the battery cover back.
7. Common Sources of CO
Common sources of potentially dangerous levels of CO are:
·Poorly maintained furnaces, gas heaters, or fireplaces.
·Dirty or plugged chimneys, or flue exhausts.5
·Poorly maintained gas, oil, or kerosene appliances.
·Internal combustion engines (e.g., automobiles,
lawnmowers, blowers).

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8. CO and Appliance Malfunctions
The following table identifies typical problems that can
produce high levels of CO.
Appliance
Fuel
Typical Problems
Gas
furnaces
Room
heaters
Oil, natural
gas, or LPG
(liquefied
petroleum
gas)
1. Cracked heat
exchanger.
2. Not enough air to burn
fuel properly.
3. Defective/blocked flue.
4. Maladjusted burner.
5. Building not properly
pressurized.
Central
heating
furnaces
Coal or
kerosene
1. Cracked heat
exchanger.
2. Not enough air to burn
fuel properly.
3. Defective grate.

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Room
heaters
Central
heaters
Kerosene
1. Improper adjustment.
2. Wrong fuel (not K-1).
3. Wrong wick or wick
height.
4. Not enough air to burn
fuel.
5. System not properly
vented.
Water
heaters
Natural gas or
LPG
1. Not enough air to burn
fuel properly.
2. Defective/blocked flue.
3. Maladjusted burner.
4. Building not properly
pressurized.
Ranges
Ovens
Natural gas or
LPG
1. Not enough air to burn
fuel.
2. Maladjusted burner.
3. Misuse as a room
heater.
4. System not properly
vented.
Stoves
Fireplaces
Gas, wood,
coal
1. Not enough air to burn
fuel properly.
2. Defective/blocked flue.
3. Green or treated wood.
4. Cracked heat

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exchanger.
5. Cracked firebox.