Same with mine. I thought the reading may be relative to baseline, but the outliers don’t inspire confidence. Its logs are also very chatting but unhelpful.
I also have this sensor and believe it’s a scam product. Temperature and humidity reading are useful. CO2 level always shows roughly the same value, regardless of the room and ventilation state (where I do see a big difference on other CO2 sensors). The VOC and Formaldehyde readings have always been 0. It’s my impression that for those 3 components the sensor just spits out some random values and it’s not measuring anything. I have not yet tried to open the device up, but I wouldn’t be surprised there are no CO2/VOC sensors in there at all. It wouldn’t be surprising given it’s price point.
I’ve just bought three of these… My current issue is it seems to only show VOC sensor and none of the others (haven’t got to comparing to other sensors yet to see likely accuracy).
After seeing your comment @kozmix I couldn’t resist opening one up to see what’s inside:
If anyone with better hardware insight has any comments I’d love to hear them… is this bogus? If so I’d like to send them back as was a fair few £ to buy a few of them
Does somebody know a non-scam alternative?
I found this: LifeControl Air Quality Sensor MCLH-08 Zigbee compatibility
but this does not seem to be available in Germany and I’m not sure if it’s measuring pm2.5 (is that always included in VOC maybe)?
CO2
VOC
temperature
humidity
I also get spikes on some readings - I suspect that the Tuya app filters out these erroneous figures and we may be able to by using a template sensor or similar