Ordered it for my basement brewery to warn of CO2 leaks. The temperature was 10°F too high for the first few hours, possibly due to the heat generated while charging the battery? In any case, it now seems accurate (+/- 1F). The CO2 sensor is quite sensitive and seems accurate enough for my application. It's sensitive enough to detect an increase in CO2 levels after standing nearby for a few minutes, and I was surprised at how much higher (from ~460ppm to 650ppm) the concentration rose when I did last night prepared the dinner. To test the alarm function I assembled a 1 gallon jug, some random hoses and gas fittings and a CO2 syringe. Adding 7–8 milliliters of CO2 to the 1-gallon jug (about 460 ppm initially) increased the internal CO2 concentration to about 2400 ppm, which is well within error for this setup (one ml of CO2 should increase the CO2 concentration of one gallon). air by approx. 260 ppm). I am happy to add this to the other Inkbird products in my brewery. Addendum: I've had this in my (cellar) brewery for several days now. After venting the CO2 in my pressurized conical fermentor, it was nice to be able to check that the CO2 levels were still well within the safe range (~600ppm) and then returned to normal within a few hours. Very happy with the purchase.