Description

When AM307/AM308/AM319 reports CO2 value as 65535ppm,  please refer to below checklist to resolve the problem.

Solution

1. Use ToolBox App or ToolBox PC software to read CO2 value of AM sensor locally. If ToolBox shows the different CO2 value from your platform, go to next step; if ToolBox shows the same CO2 value as your platform, skip to Step 3.

2. Check if the decoder on your platform is correct, reference decoder: https://github.com/Milesight-IoT/SensorDecoders

If you are not sure of it, please send your platform decoder and raw data of AM sensor to Milesight technical support.

3. Disable numerical calibration of CO2 to avoid the effect of calibration value. After disabled, read the CO2 value again to check if it is normal.

4. If the sensor reports CO2 value as 65535ppm sometimes, please upgrade the sensor to latest firmware version: https://www.milesight.com/iot/resources/download-center/#firmware-am300

Note:

1) Different hardware versions use different firmwares, please check the hardware version of your sensors via ToolBox and download the correct firmware.

2) It is suggested to connect AM sensor to computer and upgrade via USB port, which is easier and stable.

3) Refer to chapter 4.6 of user guide to complete the upgrade: https://resource.milesight.com/milesight/iot/document/am300-series-user-guide-en.pdf

5. Operate CO2 manual calibration steps to calibrate the CO2 sensor again: https://support.milesight-iot.com/support/solutions/articles/73000594771-a-guide-to-know-milesight-co2-sensor-and-calibration#Manual-Calibration

6. For AM307 and AM308, check if the battery is almost dead. Low battery level may cause the sensor collection failure.

You can use a multimeter to measure if the voltage of battery is around 3.6V. If lower, it is possible the battery is coming to dead. If you already changed the new batteries but still show abnormal value,

1) measure the battery voltage

2) check if the battery specification matches the requirements of AM30x sensors (ER14505 Li-SOCl2 Batteries, the voltage is 3.6V)

3) check if all batteries are newest.

7. Catch sensor logs via USB port for more than 5 minutes and send to Milesight technical support: How to Get Milesight Node Log File

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