Review on ⚡ Rechargeable Langkou Particulate Temperature Detector by Michael Gonzales

This unit has C02 as the main reading on the display and is mentioned first in the description. After initially reading too high for several hours, C02 settles into a plausible range for a 3,500+ sq ft house with 9ft high ceilings, also found to be pretty poor in terms of airtightness, only 4 people and nothing ablaze except for the limited use of a gas stove. It's also not much higher than outdoor CO2 levels of 400-450ppm. If you want to ensure your indoor stays below 1000ppm, that's pretty much the minimum at which you can expect unwanted effects from excess CO2. I do not yet have a calibrated CO2 device. Based on a calibrated thermometer and a combination of a humidity meter and another uncalibrated device doing the same thing, both of which agree well with each other and agree with other similar testers, a temperature reading of at least 2 degrees Fahrenheit is too high and the humidity is 6 to 10 % lower. If you compare the particulate matter values of 2.5 and 10 for this device and 3 others, the correlation is poor to terrible. This one shows PM2.5 between 12 and 13 µg/m3 while the others show 15, 25 and 32. The PM10 on this one is 16 while the other 2 read 47 and 55. I don't have a calibrated device for PM reading, and none of the others measure PM1.0. So for about $85 you get a device that seems to give you an estimate of CO2 levels, doesn't work that well with temperature and humidity, and doesn't match any other particle unit. It's only 3 stars and if the PM reading is as bad as it gets, it drops to 2 stars. Can't recommend this based on what I've seen so far.