Q: Can AM Series measure the CO2 lower than 400 ppm ?

Yes, it can measure the CO2 lower than 400 ppm except AM319, AM319 only supports displaying 400 to 2000 ppm value.


Q: Are sensors calibrated before delivery? Can AM series support sensor calibration?

Yes, AM series is calibrated before delivery and most of sensors support numberical calibration. Besides, please refer to CO2 calibration guide: A Guide to Know Milesight CO2 Sensor and Calibration.


Q: What is the PIR output for AM300 Series sensor?

It only output two status: Occupied or Vacant. When it detects the movement, it will set the status as occupied. If you need to know the exact number of people in the meeting room or within the area, it's suggested to use VS121 or VS132.


Q: Can TVOC value of AM300 series transform to other unit like ppb or mg/m3?

The TVOC value on AM300 series points an IAQ index without unit, this is calculated by a intelligence algorithm and can not transform to other unit.


Q: Seems the TVOC value is not accurate after powering on.

Please try below steps:
1. When you power on this device at the first time, keep it on about 48 hours and ensure not off during this time.
2. Put the device to an outdoor, clean environment for more than one minute, the device will calibrate automatically. This operation should be done again if the device reboots or resets.
3. It should take about 15 minutes to get stable and accurate values everytime reboot, reset or power on. 


Q: Can AM319 support both HCHO and O3 sensor? How to tell which sensor a AM319 device uses?

No, AM319 can only support either HCHO or O3 sensor, you can tell the differences by checking the Part Number (PN) on the device label.


Q: Is it easy to replace the HCHO or O3 sensor of AM319?

Yes, HCHO or O3 sensor is connected to the mainboard by a pluggable interface and it's easy for you to unplug the old one and replace with new ones.


Q: Can AM series measure dew point temperature?

Not support, it measures dry bulb temperature.


Q: What is the sampling/collecting interval of every sensor?

The sampling/collecting interval is fixed and not allow to change, please refer to below list:

Temperature30s1 min1 min
Humidity30s1 min1 min
CO22 min2 min1 min
Illuminance30s1 min10s
Motion (PIR)1min1 min5s
TVOC30s5 min1.5 min
Barometric Pressure30s1 min1 min
PM2.5&PM10//3 min


E-ink Screen

Q: Can the E-ink screen be turned off? How to turn off the screen display?

Yes, you can turn off the screen display via ToolBox or downlink command: ff2d00. For details please refer to corresponding user guide:


Q: Can the emoticon on the E-ink screen be disabled?

No, the emoticon is not allowed to disable now. But for AM319, it will not display the emoticon if you enable all sensor collection and display on the screen. If there is any requirement for it, please contact Milesight for details.


Q: Why the emoticon of AM300 series still show polluted/bad even the screen shows the environment well?

When any one of the concentrations of air pollutants of CO2, TVOC, PM2.5, PM10, HCHO/O3 exceeds the threshold, the emoticon will show polluted or bad status. If the values on the screen shows well, please use ToolBox to read if there is any other pollutant triggering the threshold.


It's not the switch off/on but full screen re-fresh every 30 or 60 minutes. E-ink screens need full screen re-fresh to remove the ghosting and ensure a good display.


Q: How to sync the time on the screen?

Please refer to article How to Sync Time on Milesight LoRaWAN Nodes. Note that if you use network server to sync the time, it will sync the time which time zone is UTC+0 by default. It's suggested to sync the time via ToolBox or send downlink command to change the time zone.


Q: Can the display modes on screen be customized?

Yes, please submit your design to Milesight and Milesight provides software customization services to achieve your requirements.


Power Supply

Q: I can't find the battery connector to fix the batteries on AM319, is it normal?

Yes, AM319 can only be powered by type-C port and does not support battery powered.


Q: Can the USB on AM series charge the batteries?

No, the USB can be only used to power the device instead of charging the batteries.


Q: Are batteries inside the device with insulating sheet when shipping?

No, but the batteries will be not put into the device when shipping, you need to install the batteries when using. If you need to install batteries before shipping, please contact Milesight before purchase.


Q: Does this device support low battery alarm?

Yes, the device will send a low battery alarm packet to network server when battery level is lower to 10%.



Q: Can I use AM series to monitor indoor environment directly without using LoRaWAN features?

Yes, you can check the data locally via screen or Milesight ToolBox.


Q: Can the device work with other brand gateways?

Yes, the device can work with other brand gateways which supports standard LoRaWAN protocol.


Q: How the device achieve secure communication with gateway?

The device communicate with gateway via LoRaWAN protocol which support AES128 encryption and a series of communication mechanism, for details please refer to article:


Q: What is the default App EUI and AppKey? Can the device support random AppKeys?

The default App EUI is 24E124C0002A0001 and Appkey is 5572404C696E6B4C6F52613230313823.

Yes, the device support random Appkey pre-configuration and you can ask Milesight for it before purchase.


Q: Are device EUI, App EUI and Appkey editable on your device?

The device EUI is unique and non-editable, App EUI and Appkey can be edited via ToolBox.


Q: How to connect device to network servers like TTN, Chirpstack, Actility, Senet, etc?

Yes, please refer to Milesight IoT knowledge base:


Q: How to decode the data? Where can I find the decoder?

For the definition of data please refer to corresponding device user guides:

Milesight also provides decoder examples here: You can modify these decoders according to your platform requirements.


Q: Why there is decode error even I use the decoder example provided by Milesight?

Please change your device LoRaWAN version to V1.0.2 or V1.0.3 and check again.


Q: What reporting interval can the device be configured?

1 to 1080 minutes is configurable. It's not suggested to shorten the interval to second which will reduce the battery life quickly.


Q: What is the working mechanism of rejoin mode feature?

The device will send a specific number of LinkCheckReq MAC packets to the network server every 30 mins or longer to validate connectivity; If there is no response after the specific number of packets , the device will re-join the network.


Q: Can the device get confirmation to know if the data is sent to server?

Yes, please enable Confirmed Mode on ToolBox. If the device does not receive the confirmation, it will send the data once again.


Partial support, please refer to corresponding user guide for downlink commands:


Q: Can the device send any alarm message (Email, SMS, etc.) when threshold is triggered?

No, but it will send threshold alarm packet to network server right away. You can connect the device to Milesight IoT Cloud which support Email alarm or mobile App pushment, or connect to other IoT platforms which support alarm notification services.


Q: How to use data retransmission feature? Can device retransmission data if it loses power supply suddently?

Please refer to article How to Use Data Retransmission Function on Milesight Sensors. This feature can not work with sudden changes of sensor itself like losing power supply or changing LoRaWAN parameters, it can work when losing connections with gateway or server for some times.


Q: How to distinguish periodic report and retransmission historical data? Is there unique sequence number or timestamp to with each retransmission?

The reported format between periodic report and re-transmission data is different, and each re-transmission packet includes timestamp. For packet format details please refer to corresponding user guide.


System & Maintenance

Q: Can the device upgrade remotely via LoRaWAN?

Not support, Milesight only provides locally upgrade via Milesight ToolBox App or ToolBox PC software now.


Q: Where to find the latest firmware of devices?

Please find the latest firmwares here:


Q: Can I backup the configurations of one device and import to another device?

Yes, both Milesight ToolBox App and software supports backup feature, this should ensure both devices have the same model and frequency.


Q: Can all default parameters of pre-configured before shipping?

Yes, Milesight provide OEM services to pre-configure the device settings before shipping to save your time to configure bulk of devices.


Q: Can Milesight provide code to modify the firmware?

No, the device does not support firmware modification by yourselves. If you have any extra feature requirements, please contact Milesight for software customization services.


Q: Does the device have any API to get the data?

No, the device can only send data to gateway via LoRaWAN. It's suggested to connect device to Milesight gateway which provides MQTT/HTTP API to send data to your applications.


Q: How to get device debug logs for troubleshooting?

Please refer to article How to Get Milesight Node Log File.


Q: Can NFC of the device switch off?

Not support , but you can set a password for every device to avoid modifying configurations.


Q: How to export the data stored in AM300 series? What is the export format?

Please use Milesight ToolBox App or PC software to export the data as csv file.