Intuitive operation, but most annoyingly, it doesnt save your preset limits. Blue backlight light turns off after a few seconds of inactivity. Note that it has a 2 minute warm-up to calibrate itself. No details are provided about the calibration process though.__Great little carry case with USB-A to USB-C charging cable and simple operation manual inside. Battery life seems solid and arrived without the need to charge it beforehand.__Review your governments environmental agency acceptable limits to set the correct acceptable thresholds for CO2, TVOC and HCHO.

Intuitive operation, but most annoyingly, it doesn't save your preset limits. Blue backlight light turns off after a few seconds of inactivity. Note that it has a 2 minute warm-up to calibrate itself. No details are provided about the calibration process though. Great little carry case with USB-A to USB-C charging cable and simple operation manual inside. Battery life seems solid and arrived without the need to charge it beforehand. Review your government's environmental agency acceptable limits to set the correct acceptable thresholds for CO2, TVOC and HCHO.

Intuitive operation, but most annoyingly, it doesnt save your preset limits. Blue backlight light turns off after a few seconds of inactivity. Note that it has a 2 minute warm-up to calibrate itself. No details are provided about the calibration process though.__Great little carry case with USB-A to USB-C charging cable and simple operation manual inside. Battery life seems solid and arrived without the need to charge it beforehand.__Review your governments environmental agency acceptable limits to set the correct acceptable thresholds for CO2, TVOC and HCHO.