Intermittent connectivity and general questions about Industrial IoT Wireless Particulate Matter Sensor

Hardware
1

Hello,

I am writing to understand better how this device works. A former coworker purchased it and I am trying to use it. I have some general questions and one technical one.

General

  1. How does the sensor measure the weight of the particles? If I understand correctly, there is a laser/light scattering device inside that can measure the size of the particles, that makes sense, but how does it measure/determine the mass?

  2. Do these sensors need to be calibrated?

  3. For the PM10 measurements, are the values being reported the sum of all the smaller particles PLUS those at PM10 or is it ONLY particles that are 10 microns?

  4. What is a good way to interpret the data? A current coworker plotted out some data versus time and then averaged it. It was perhaps a coincidence, but the average concentration of the PM1.0 was 0.9 ug/m3, for PM2.5 was 2.5 ug/m3, for PM4.0 was 3.7 ug/m3, and for PM10 was 4.0 ug/m3. To me, it seemed curious that the average concentration value was almost exactly the same as the particle size in 3 of the 4 measurements. Does this seem OK to you?

Specific question

  1. the sensor seemingly has trouble reporting/connecting to the internet/modem/port because the data doesn’t arrive at specific intervals. There will be gaps in the data times and then a download. Can you help me figure out what is going on here?
2

we use tis sensor chip.

Yes, we have worked with few of your engineering folks and i remember one time the issue was that you were using a free ubidots account and it was not letting all the variables go through.

You can factory reset the sensor and it will send data every 30 min. the minimum data transmission interval you can set it 30 sec.

Thanks

3

General questions still remaining:

  1. How does the sensor measure the weight of the particles? If I understand correctly, there is a laser/light scattering device inside that can measure the size of the particles, that makes sense, but how does it measure/determine the mass?
  2. Do these sensors need to be calibrated?
  3. For the PM10 measurements, are the values being reported the sum of all the smaller particles PLUS those at PM10 or is it ONLY particles that are 10 microns?
  4. What is a good way to interpret the data? A current coworker plotted out some data versus time and then averaged it. It was perhaps a coincidence, but the average concentration of the PM1.0 was 0.9 ug/m3, for PM2.5 was 2.5 ug/m3, for PM4.0 was 3.7 ug/m3, and for PM10 was 4.0 ug/m3. To me, it seemed curious that the average concentration value was almost exactly the same as the particle size in 3 of the 4 measurements. Does this seem OK to you?

Thanks.
Catherine