Buzzer AL L/AL H:
When AL Lis on, the buzzer sounds "Ta Ta Ta"; when AL His on, the buzzer sounds "Bi Bi Bi".
RS485 INTERNAL communications:
Please use the 4 Pole 3.5mm headphone plug. The headphone plug contacts are defined as below:
For long-distance communication, it is necessary to use a dedicated isolated line to ensure communication
quality. The wiring method is as below:
Power off:
Switch the Power Key (○A) off.
Note: When the device is charged with USB, it cannot be turned off.
Calibration:
(1) Single-point calibration
At the same time, long press “▲(○G)“ and “▼(○J)“ key, CAL is displayed on the screen. Press the “M1” key
(○F)to select the sensor that needs to be calibrated. Press the “▲(○G)/▼(○J)” key to edit the parameters, and
then press the “Enter” key (○I) to proceed the next setting. Zone1 displays the unadjusted raw value; Zone2
displays the adjusted value, and it is also the value of returning to the main screen; Zone1-Zone2=adjustment
amount. After finishing the setting, press and hold the “M1” key (○F) to return to the main screen.
(2) Two-point calibration
At the same time, long press “▲(○G)“ and “▼(○J)“ key, CAL is displayed on the screen. And then long press
the “M2” key (○H), CAL L is displayed on the screen. Next, press the “M1” key (○F) to select the sensor that
needs to be calibrated (CO2→CO→O2→NH3→PM2.5→RH→AMB) and the corresponding unit will blink.
Press "▲(○G)/▼(○J)" key to adjust the value of the standard gas concentration. Press “Enter“ key (○I) to
switch CAL H (High gas concentration calibration)/CAL L (low gas concentration calibration). The ppm unit is
not flashing for a moment, indicating that the calibration value has been stored. Long press the “M2”key (○H)
foracalibrationcalculation.Atthesametime,thescreendisplaysthecalibrationreadingtoconfirmtheaccuracy.
Short press the “M1” key (○F) to set the next gas calibration, or long press the “M1” key (○F) to return to the
main screen.
Clear Two-point calibration:
Set the same calibration value for CAL L and CAL H, and then proceed the calculation.
After the calibration is completed, the original calibration value is cleared.
Rechargeable Batteries
Battery message:
‘Battery OK’:
Measurements are possible
‘Battery Low’:
The battery needs to be recharged,
measurements are still possible
‘Battery Exhausted’:
Measurements are not
possible
Battery installation:
This device is supplied with Li-ion 18650 3.7V rechargeable battery *3 pcs.
Please confirm whether batteries + polarity are Li ion18650 positive bump specification and install batteries in
the correct polarity. If the battery polarity is reversed, the capacity will be insufficient and the battery life will be
shortened.
Battery charging:
The charge lamp (○E) lights up while charging; the charge lamp (○E) goes off when charging is completed.
(5V/1A USB adapter charger)
Note: During battery charging, the temperature of the device will rise by 5°C~10°C. At this time, the
measurements of temperature and humidity will be affected by temperature rise. Cause an impact on
the accuracy of temperature when charging, please use a fan to blow toward the temperature sensor
(○C) directly in order to get a compensated balance of temperature and humidity between temperature
sensor and surrounding area.
Safety Instructions
Warning: Your safety is very important to us. To ensure to use the device correctly and safely, we would like
to draw your attention to read the warning and entire User Manual before using the device. These
are important safety information and should be observed at all times.
1. Please handle the device lightly, do not subject the device to impact or shock.
2. Do not immerse the device in water. Water can cause electric shock, fire or malfunction which may result in
damage.
3. Do not keep thedevice under the hot and moisture environment. Keepthe device away from the heat source
or near water.
4. Please use a standard USB power supply (such as PC's USB port, universal AC adapter with USB port).
Improper power supply can cause serious damage to the device, or result in injury or death to the user.
Product Care
To ensure you receive the maximum benefit from using this device, please observe the follow guidelines.
1. The maximum capacity of the SD card is 16G.
2. During battery charging, the temperature of the device rises. The temperature and humidity sensors will
be affected. At this time, measurements are only for reference. After batteries are fully charged and the
device cools down, measurements are again, reliable.
3. Repair –Do not attempt to repair the device or modify the circuitry by yourself. Please contact with the
4. Caution –The CO and NH3 sensors must be replaced every 3 years.
5. Cleaning –Disconnect the power beforecleaning. Use a damp cloth,do notusetheliquid cleaning agent,
such as benzene, thinner or aerosols.
6. Maintenance – Recommend that the user conducts a comprehensive test and calibration every year
to ensure normal operation of the device.
Specifications
0~9,999ppm
(5,001~9,999ppm
over range)
±50ppm or 5% of reading,
whichever is greater (0~5,000ppm)
0~100ppm
1ppm
±15% or ±15 μg/m³, whichever is
greater
±3%@25°C (20~80% RH),
others ±5%
50~110 kPa ±0.4kPa
0~40°C (32~104°F), 0~95% RH, non-condensing, with lithium-ion batteries
0~50°C (32~122°F), 0~95% RH, non-condensing, without lithium-ion batteries
-20~60°C (-4~140°F), 0~85% RH, non-condensing, without lithium-ion. batteries
Rechargeable Battery : Li-ion 18650 3.7V (device uses 3)
AC Adapter : 5V±5% >1A, 100~240 VAC, 50/60 Hz
depend on SD card capacity (max.16G SD card)
RS485 ModBus BR19200、N、8、1 (INTERNAL)
Volume
Weight 305g (without batteries)
Dimension 204.5x91.7x49.6 mm (8.1x3.6x2 inch)
Note: After power-on, it would take 20 minutes for the device to stably measure the temperature and RH.
EMC/RFI: Readings may be affected if the unit is operated within radio frequency electromagnetic field
strength of approximately 3 volts per meter, but the performance of the instrument will not be
permanently affected.
Sensor warm-up time and logging Interval:
Installation Instructions
You can place the CM-500 series on atable (please pull out the Housing Stand (P) or hang it on the wall.
Please note the following: When hanging the CM-500 on the wall, it is important to choose a suitable
location to install the device, next simply fix a screw to the wall and begin monitoring.
Package Contents
Handheld Multi Gas Detector
Manual
USB 1.5M cable
SD Card
CO2 Meter, Inc.
131 Business Center Drive,
Ormond Beach, FL 32174
No. Sensor Warm-up time Data logging interval time setting
After powering on and standby time,
data logging can be operated. Data logging interval
time setting
1 CO2＜1 minute After power on 5 minutes 2 seconds~60 minutes
2 CO 5 minutes After power on 5 minutes 2 seconds~60 minutes
3 O2＜1 minute After power on 5 minutes 2 seconds~60 minutes
4 NH3 5 minutes After power on 5 minutes 2 seconds~60 minutes
5 PM2.5
PM10 ＜1 minute After power on 5 minutes 2 seconds~60 minutes
Ref.No.：122018
07-21-20
The quickest way to obtain technical support is via email. Please send all support inquiries to
In your email, please include a clear, concise, definition of the problem and any relevant troubleshooting
information or steps taken so far so we can duplicate the problem and quickly respond to your inquiry.
For additional CM-500 Multi Gas Detector Information, you can reference below.
See CO2Meter, Inc. Terms & Conditions at, https://www.co2meter.com/pages/terms-conditions
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