Carbon Monoxide/Carbon Dioxide IAQ Meter Carbon Monoxide Measurement Range (PPM) 0 to 999 Carbon Dioxide Concentration 0 to 9999 ppm Temp Range -5 Degrees to 140 Degrees F Relative Humidity Range 0 to 99.9 Percent Dew Point Range -5 Degrees to 140 Degrees F Wet Bulb Temperature Range -5 to 140 Degrees F Humidity Accuracy +/-3 Percent Accuracy +/-10 Percent Resolution 0.1 Percent Display Triple LCD Auto Power Off Yes Low Battery Indicator Yes Data Hold Yes