CO/CO2 IAQ Meter Carbon Monoxide Measurement Range (PPM) 0 to 1000 ppm Carbon Dioxide Concentration 0 to 9 999 ppm Temp Range -4 Degrees to 140 Degrees F (-20 Degrees to 60 Degrees C) Relative Humidity Range 1 to 99.9 Percent Dew Point Range -4 Degrees to 140 Degrees F (-20 Degrees to 60 Degrees C) Wet Bulb Temperature Range 23 Degrees to 140 Degrees F Oxygen Concentration Not Applicable Humidity Accuracy +/-5 Percent Accuracy +/-1 Degrees F/0.6 Degrees C