Dwyer DTR-2D404 Carbon Dioxide and RH Transmitter, Duct Mount. Range: CO2: 0 to 2000 ppm; Relative humidity: 0 to 100% ; Accuracy: ±40 ppm + 3% of reading (CO2); ±2% (RH). Temperature Dependence: 8 ppm/ °C at 1100 ppm. Non-Linearity: 16 ppm. Pressure Dependence: 0.13% of reading per mm of Hg. Response Time: 2 minutes for 99% step change. Temperature Limits: 32 to 122°F (0 to 50°C). Duct Air Velocity Range: 0-4000 FPM (20.32 m/s). Humidity Limits: 10 to 95% RH (non-condensing). Power Requirements: 16 to 35 VDC / 19 to 28 VAC. Power Consumption: Average: 2 watts; Peak: 3.75 watts. Sensor: Single-beam, dual-wavelength NDIR. Output: Current: 4 to 20 mA (max 500 Ω); Voltage: 0 to 5 VDC or 0 to 10 VDC (min 500 Ω); Weight: 5.6 oz (158.8 g). Enclosure Rating: IP20. Agency Approvals: CE