Review on 🌡️ GZAIR Temperature and Relative Humidity 0-9999Ppm: Test, Measure, and Inspect by Bill Russett

From what I can tell the sensor seems accurate enough and behaving as expected. If left outside, it falls to a baseline of 350-450ppm - sometimes a little lower, but about. With the windows closed in my apartment it rises to over 1000ppm overnight and drops back to 400-700 when I open the window or turn on the AC. With the burner on, you can see the ppm slowly increasing in the kitchen. All is well. Unfortunately, as with many products from other manufacturers, the user interface is secondary, making it all but useless for tracking measurements over time. For example, there is a mode that shows you a graph for the last 24 hours. But oddly, the maximum value on the Y-axis is 600ppm and cannot be changed, making it impossible to see the peaks! Also, the numbers on the x-axis are inverted and don't make sense. Even though I selected degrees F in the settings, the temperature graph shows the reading in degrees Celsius. Finally, the instructions are terrible and I still couldn't figure out what some of the settings, such as B. "Limit CO2 installation", actually cause. There doesn't seem to be a way to download data or update the firmware, leaving you with a fairly accurate sensor with barely adequate data-logging capabilities. I'll probably bring that back and move on to a more professional device with a proper data logger.