Fieldpiece SCM3 User 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 determined 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 display. By constantly going towards the area of higher 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 environment. (There will be a 10 second countdown.)
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 highest 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 sample must be near ambient.
6. Turn off by holding ON/OFFfor 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 backlight 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 battery 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 measure the gases in a flue.
3. Verify O2and CO2levels are close to manufacturer’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 O2and CO2are 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 filter built inside the sensor to filter out trace concentrations of SO2, NO2, and most hydrocarbons. If exposed to high concentrations of harmful 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 exchanger is good. A CO detector can indicate that a heat
exchanger may be cracked only if all of the following 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 O2and CO2are close to manufacturer’s specified levels before testing combustion
equipment such as heaters, boilers or stoves.
Do not rely solely on a carbon monoxide measurement to determine if a heat exchanger is bad.
See “CO detectors and cracked heat exchangers” to the right.
!
!
WARNING
Extended exposure to even relatively low carbon 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.
!
!
AUTO-OFF
BATT CHECK
Carbon
Monoxide
Detector
Measures
CO in PPM.
ZERO
SCM3
ON/OFFMUTE
PRESS FOR
MAX
1 SECOND
CO exposure effects
Effects can vary significantly depending on
age, sex, weight, and overall health.
Coffee cup test
To demonstrate that your CO sensor works, turn
a ceramic coffee cup upside down and slide it over
the edge of a counter (or desk) to expose about a
third of the mouth of the cup. Burn a cigarette
lighter inside the exposed mouth of the cup. Don't
burn the counter. When the flame starts to flicker,
you've burned up most of the oxygen in the cup creating carbon dioxide and now you're starting to produce carbon monoxide. Bring the flame in and out
of the mouth of the coffee cup to just keep the flame
alive. The longer you keep the flame flickering, the
more CO you produce. After 10 seconds of flickering, extinguish the flame and put the CO head in the
mouth of the cup. You should see readings in the
100s. Take it out if it approaches 1000PPM.
Limited warranty
This meter is warranted against defects in material or workmanship for one year from date of purchase. Fieldpiece will replace or repair the defective
unit, at its option, subject to verification of the
defect.
This warranty does not apply to defects resulting
from abuse, neglect, accident, unauthorized repair,
alteration, or unreasonable use of the instrument.
Any implied warranties arising from the sale of a
Fieldpiece product, including but not limited to
implied warranties of merchantability and fitness for
a particular purpose, are limited to the above.
Fieldpiece shall not be liable for loss of use of the
instrument or other incidental or consequential
damages, expenses, or economic loss, or for any
claim of such damage, expenses, or economic loss.
State laws vary. The above limitations or exclusions may not apply to you.
Obtaining service
Contact Fieldpiece Instruments for one-price-fixall warranty service pricing. Send check or money
order for the amount quoted. Send the meter freight
prepaid to Fieldpiece Instruments. Send proof of
date and location of purchase for in-warranty service. The meter will be repaired or replaced, at the
option of Fieldpiece, and returned via least cost
transportation.
Optional pump
Use the model AOXP2 pump to
extract samples from hard to reach
places or from locations where the temperature is high (such as a flue).
For potentially high concentrations of
CO, pump slowly and stop if the measurement approaches 2000PPM.
Carbon monoxide concentrations
will begin to show in two or three
squeezes. For final reading,
pump until the reading stabilizes,
about 30 squeezes.
Press MAX on SCM3 to hold
highest reading.
Fieldpiece Instruments, Inc.
California, USA
www.fieldpiece.com
v09
More Products From Fieldpiece
Modular Expandability
Modular expandability is the ability for accessory
heads and meters to change configurations to
match the various needs of an HVAC/R technician.
Accessory heads (the sensors) send out a mV
signal, which represents the value of the measurement, an attached meter. Heads can attach directly
to the top of a Stick meter, DL3 data logger, or
EHDL1. They can also plug into any meter with mV
ranges using ADLS2 leads.
Stick Meter
This is the heart of modular expandability . In addition to being a full functioning multimeter, any accessory head can be used with it.
Model HS36
Non contact voltage
Magnetic hanger
Autoranging
Backlight
Temperature
Volts, amps, ohms
Frequency
Microfarads
Includes:
HS36 Meter
ACH4 Current Clamp
ATB1 K-type T/C
ADLS2 Deluxe Leads
ANC1 Case
Accessory Heads
Accessory heads are the sensors of multiple
parameters measured by technicians every day.
They send a mV signal to an attached multimeter.
The multimeter will display whatever the head is
measuring. Instead of having to purchase and carry
a separate instrument for each parameter, a technician can use multiple heads and a single multimeter
to do the job.
Here are four of the many heads available:
AAV3 Air Velocity and Temperature
ADMN2 Dual-Port Manometer
AVG2 Digital Vacuum Gauge
AOX2 Combustion Check
Standalone Combustion Check
The SOX2 allows you to easi-
ly calibrate combustion equipment such
as boilers or furnaces
to the manufacturer’s
specified Excess Air
%, CO2%, or O2%.
Tuning the Excess
Air, CO2, O2stack
temperature and temperature rise to match
the appliance manu-
facturer’s specifica-
tions will increase
efficiency and help
maximize per-
formance and life
expectancy of the
equipment. Tuning
typically involves
adjusting the air/fuel
ratio.
AirVelocity
&Temperature
Head
English
READLOBATT
ON
LCDX
100
Average
(16sec)
Metric
Real
time
AAV3
AUTO-
OFF
English Metric
Ft/min M/s
KM/hrMPH
ºF ºC
OFF
aaaaa
aaaaa
aaaaa
aaaaa
aaaaa
aaaaa
T2
T2
2
T2
Natural
Gas
Oil #2 Propane
°C °F
EA/CO2/O
2
H/MAX/ MIN
FUEL
ON/OFF
Combustion
Check
Excess Air and %CO
2
calculated from %O
2
SOX2
AUTO-OFF
BATTERY CHECK
PRESS FOR
1 SECOND
Temp Cal
CO ppm Effects
9 ppm
Minim al . Max all owabl e concent rat i on
for eight hours (EPA and ASHRAE ).
35 ppm
Max for continuous exposure for one
hour (EPA and ASHRA E ).
50 ppm Max for eight hours (OSHA).
100 ppm
Trips ins talled CO det ec tors. UL2034
spec i fies a max exposure of 100 min.
200 ppm
In two to t hree hours : sli ght
headache, tiredness, dizziness,
nausea. UL2034 specifies a max
expos ure of 35 mi n.
400 ppm
In one or two hours: frontal
headaches . In three hours: l i fe
threat ening. UL2034 spec i fies a max
expos ure of 15 mi nutes.
800 ppm
In forty five minutes : di zzi ness,
nausea, and convuls i ons.
800 ppm In two to three hours : death.
1600 ppm In one hour: death.
6400 ppm In fifteen minut es: death.
12800 ppm In three minutes: death.
P1 P2
Dual-Port
ON
Manometer
Accessory
Lo Batt
Head
0.1
ENGLISH
Resolution
0.01
METRIC
(LCD/10)
P1-P2
P2
P1
AUTO
ZERO
OFF
ADMN2
Combustion
Check
Lo Batt
STABLE
Fuel Type
TEMP
%CO
2
%O
2
AUTO
T/C
°C °F
CAL
OFF
AOX2
ON
GAS
OIL
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