Q1Is EM500-PT100 with thermocouple type T?

Answer: No, PT100 probe is platinum thermal resistance.

Q2Does WS558 measure the total consumption or each line? Can WS558 measure and drive the consumption of the 8 lines independently?

Answer: WS558 can only measure the total consumption, and it doesn't support to measure per line consumption independently.

Q3Is there any other way to upgrade sensor's firmware expect upgrade on the scene? Does support to upgrade sensor's firmware via sending downlink on gateway?

Answer: Currently there is not other way to upgrade remotely, it only supports to upgrade sensor's firmware on the scene. 

Q4Do you have any sensor to measure water temperature in pipes, for air conditioning, fan-coil circuits in hotels?

Answer: Yes, it is recommended to use EM500-PT100 which support wide measuring range and multiple kinds of probe types for fixing.

Q5Can EM500-LGT sense the lux at 1m from floor? How high it must be installed?

Answer: Yes, EM500-LGT can sense the light of 1m. As for installation, there is no height limitation.

Q6Does AM series support NFC Radio ON/OFF? Does it support Tamper alert switch?


  1. Not support, but you can set a password for preventing anyone to configure this device.

  2. Not supprt temper alert switch, but AM series sensor has a theft-deterring screw for security.

Q7What's the difference between EM320-TH and EM300-TH?

Answer: EM320-TH is a pro version temperature and humidity sensor and has more advantanges: 

1. Equips with Sensirion SHT41 chip for higher accuracy;

2. Higher waterproof design and lower response time;

3. Data traceability, which supports to store 3000 sets of historical data locally and data retransmission;

4. Wall-mounted verison and Magnet verison optional to meet different scenarios;

5. FDA-approved food contact material which can be applied in cold chain, refrigerator,  pharmacy or some special scenarios.

For more details please refer to EM320-TH LoRaWAN® Temperature and Humidity Sensor | Milesight IoT

Q8Does EM500-PT100 rust if use it to measure the temperature of salt water?

Answer: No, it will not rust as PT100 probe is covered with 304 stainless steel.

Q9Why I always lost connection or failed to save configuration when accessing to VS121 via Wi-Fi?

Answer: Please double check the distance between the PC and VS121, it’s recommend to place the PC to VS121 not more than 2-3 meters when configuring via Wi-Fi.

Q10For the EM310-TILT sensor, why when axis around 0° the result will closer to real angle than which in 90°?

Answer: Due to algorithm of the device, when axis reaches to 90° the accuracy is lower to ± 2°.

Q11Is it possible to connect our own 15 meters extension cable and PT100 sensor to EM500 device? Do we need to calibrate on EM500?

Answer: Yes, it support to connect your own PT100 sensor and extension cable, and please ensure your PT100 sensor meets below specifications:

1. PT100 sensor type is 3-wire; 4-wire is not worked with EM500 device;

2. Due to the software limitation, the sensor can only measure the temperature range matching the software range. For example, if you have a device EM500-PT100-T200, it can only be used for measuring range between -50℃ to 200℃;

3. If there are deviation in the measured data due to the extension cable being too long, it is recommended to calibrate the values in your server since the EM500 does not support to calibrate PT100 value.

Q12When installing EM500-SWL sensor, how much depth should I install it inside the water? When the probe goes out of water, will it start measuring the air gap between sensor and water?

Answer: The installation depth depends on the probe measurement range and the depth you want to measure, and please ensure the probe which is 140mm height should all inside water. The water level sensor can only measure the gauge pressure of water and convert to water level, so when probe out of water, it can not measure air gap.

Q13For EU868 sensor, when setting to SF12 and report data every 1 minute, why sensor only report data every 3 minutes?

Answer: It's may limited by the Duty Cycle prescribed by government. In Europe, the duty cycle is commonly set to 1%, which means the device can only transmit data within 1s if during a period of 100s, if the sensor does not complete the transmission within 1s, it has to send the rest of data in next uplink period of 100s. When the sensor send data via SF12, it will take more times to transmit the data and may have to wait for the next period.

Q14Questions about WS302:

1. What’s the meaning of the units: LA, Leq and Lmax ?

2. What is the sampling interval of sound without fast weighting?

3. Can I put this device into an external box for outdoor use?


1. LA is the lastest sampled SPL(Sound Pressure Level), Leq is the equivalent continuous SPL during reporting interval, Lmax is the max sampled SPL during reporting interval.

2. The sampling interval of sensor is 10 seconds.

3. It’s not suggested to use the box to cover the holes on the device since the holes are used for microphone to measure the sound. WS302 is designed for indoor use only.

Q15Why the TVOC value of AM300 V2 series is not accurate in normal environment?

Answer: It's recommended to power on and place sensor standing in the environment 48 hours for aging process to avoid the inaccuracy TVOC value. 

Q16Why when moving EM300-TH to different temperature environment, EM300-TH will take quite long temperature sensing time?

Answer: Since the EM300-TH uses IP67 shell, it will take some times to let the air flow to temperature sensor. As our test, when temperature drops from 55℃ to 25

, it will take about 1 hour that EM300-TH can reflect the actual temperature. But in the normal environment which temperature will not change in a rapid process, EM300-TH can still present the accurate temperature value quickly.