Fieldpiece SCM3 - Carbon Monoxide Detector - Manual

Standalone Carbon
Monoxide Detector
Model: SCM3
OPERATOR’S MANUAL
Description
The model SCM3 standalone carbon monoxide
detector measures carbon monoxide in parts per
million (PPM). It is intended to measure levels of
CO in still, ambient air. In many cases, it can help
pinpoint sources of CO.
The SCM3 uses a catalytic chemical sensor that
does not consume chemicals. Life is primarily deter-
mined by the type of exposure.
The most practical application of the SCM3 is to
determine if the indoor CO levels are higher than
outdoor levels and to determine the source. This
instrument reacts quickly to changing CO levels.
"Walk around" test
The SCM3 responds almost instantly to changes
in CO levels in the air. If you see a difference in CO
levels from outside to inside, you need to find the
source of the CO. Walk around and watch the dis-
play. By constantly going towards the area of high-
er concentration, you can determine the source of
the CO.
Persistent sources of CO, such as malfunctioning
combustion equipment in occupied spaces, must be
serviced immediately. These can be life threatening.
In addition to the “walk around” test, the SCM3
can be used for filtered flue testing using the
optional AOXP2 hand pump. (See Optional pump
section.)
How to use
1. Turn on by holding ON/OFF for 1 second.
2. Let stabilize for 10 seconds in a CO free envi-
ronment. (There will be a 10 second count-
down.)
3. Take the instrument outdoors and set it to zero.
Then bring indoors to take measurements.
4. Expose sensor to a still, stable air sample
between 32ºF to 105ºF and 15%RH to 90%RH.
Temperature and humidity changes will result in
unstable readings. The sensor reacts to the
presence of CO in instantly. Take the final
measurement when reading stabilizes on the
display.
Note: If sampling above the indicated temperature
range, use an AOXP2 pump. This will allow for
more stable readings.
5. For initial tests, walk around the building and
monitor the display to determine areas of high-
est CO concentration. To measure air from a
register or a flue, use a pump or measure out of
the air stream. Hot blowing air can adversely
affect the reading. The temperature of the sam-
ple must be near ambient.
6. Turn off by holding ON/OFF for 1 second.
Storage
Do not store in areas containing solvent vapors.
This includes aerosols such as air-freshener, wax
polish, window cleaner, and all organic solvents.
Zero set
As needed, set reading to zero in a known zero
CO atmosphere and in a temperature similar to the
sample air to be tested. Zero only when ambient air
is within specifications and probe is in equilibrium
(temperature and relative humidity) with ambient.
To zero, hold the ZERO
button for one second or until
“ZEro” is displayed. (Note:
For safety reasons the
SCM3 will not zero if reading
is above 5ppm.)
Backlight
Press the backlight button ( ) to toggle the back-
light of the display.
MAX button
Press the MAX button to hold the maximum
measurement from that point until the meter is
turned off or MAX is pressed again.
MUTE button and Battery Check
Press the MUTE button to silence the meter
beep. The MUTE button when held for one second
or more will show the remaining percentage of bat-
tery charge on the main display.
Auto power off (APO)
Hold the MUTE button down while turning on the
SCM3 to disable APO.
Specifications
Range: 0 to 1000PPM (2000PPM with 5 minute
max exposure time)
Initial accuracy at 73ºF±9ºF, <75%RH:
0-15ppm ±5% reading ±1 ppm after zeroing
16-35ppm ±5% reading ±2 ppm after zeroing
36-1000ppm ±5% reading ±5ppm after zeroing
Display: Updates real-time
CO air sample temperature range: 32 to 105°F
Operating environment: 32 to 122ºF (0 to 50°C)
Operating relative humidity: 15 to 90%RH, non-
condensing
Storage temperature: -4ºF to 140ºF, 0 to 80%
R.H. with battery removed from meter.
Sensor type: Electrochemical (specific to CO)
Sensor calibration: Factory calibrated on
205ppm
Long term drift: <5% / year (depending on use)
Battery: 9V
Battery life: Approx.150 hrs typical (Alkaline)
Auto power off (APO): 15 minutes
Precautions
1. Do not measure gas engine exhaust or other
high CO or highly contaminated gases. High
levels of CO and other contaminants can ruin
the sensor and be a health hazard.
2. Do not take readings directly in stream of air at
register or in a flue. Use AOXP2 pump to meas-
ure the gases in a flue.
3. Verify O
2
and CO
2
levels are close to manufac-
turer’s specification before testing combustion
equipment such as heaters, boilers or stoves.
This helps prevent the SCM3 from being
exposed to CO levels that could potentially
damage the sensor. If O
2
and CO
2
are within
the manufacturer’s specs, then the combustion
equipment should be producing minimal CO.
4. Allow enough time for SCM3 to reach ambient
temperature and %RH.
5. The sensor has a permanent unreplaceable fil-
ter built inside the sensor to filter out trace con-
centrations of SO2, NO2, and most hydrocar-
bons. If exposed to high concentrations of harm-
ful chemicals or dirt, the filter can deteriorate
and/or impede diffusion of CO to the sensor.
CO detectors and cracked heat
exchangers
A CO detector cannot tell you if a heat exchang-
er is good. A CO detector can indicate that a heat
exchanger may be cracked only if all of the follow-
ing conditions occur simultaneously:
1. The flame must generate high concentrations of
CO (lack of oxygen, excess fuel, high temp).
2. Enough exhaust gases must be emitted from
the heat exchanger crack.
3. The exhaust gases from the crack must not be
diluted too much before coming in contact with
the sensor. A cracked heat exchanger may leak
CO in a small stream. You may measure high
concentrations at one point but low concentra-
tions only an inch away.
4. The heat exchanger must be the only possible
source for the CO detected.
CAUTION
Do not take measurements directly at a
tailpipe, or at a register. See “Precautions” below.
Make sure O
2
and CO
2
are close to manufac-
turer’s specified levels before testing combustion
equipment such as heaters, boilers or stoves.
Do not rely solely on a carbon monoxide meas-
urement to determine if a heat exchanger is bad.
See “CO detectors and cracked heat exchang-
ers” to the right.
!
SCM3
ON/OFF MUTE
ZERO
MAX
Carbon
Monoxide
Detector
Measures
CO in PPM.
PRESS FOR 1 SECOND AUTO-OFF BATT CHECK
!
WARNING
Extended exposure to even relatively low car-
bon monoxide concentrations can be hazardous
to human health. Evacuate areas of significant
CO concentration immediately. See the CO
Exposure Effects on the second page of this
manual.
! !