CO2 Transmitter, Mounting Location Return Duct, Air Quality Measurement CO2, CO2 Accuracy +/-30 ppm + 3 Percent of measured value, Sensing Element Type Not Applicable, Loop Resistance 10k ohms, Power Required 24V DC +/-20 Percent/24V AC +/-10 Percent, Output 0 to 10V DC, 40 to 20 mA, Display Type Digital, Housing Material Polycarbonate, Housing Color Blue/White, Minimum Operating Temperature 32 Degrees F, Maximum Operating Temperature 122 Degrees F