The Dwyer CDWP Series carbon dioxide transmitter accurately monitors CO₂ concentration in industrial, agricultural, and indoor environments to help achieve energy savings . It utilizes a single-beam dual-wavelength non-dispersive infrared (NDIR) sensor that eliminates light source aging effects, increasing sensor life and accuracy . This sensing technology provides superior accuracy compared to Automatic Baseline Correction (ABC) methods, which can unintentionally shift calibration based on CO₂ levels and barometric pressure conditions .

The transmitter features a rugged IP54 die-cast aluminum housing with an exterior gray finish that withstands a 168-hour salt spray corrosion test, protecting the sensor from splashing liquid and airborne dust . This makes it ideal for harsh environments such as animal husbandry, mechanical rooms, CO₂ refrigeration monitoring, and greenhouses .

The CDWP Series is available in three measurement ranges: 0-2000 ppm, 0-5000 ppm, and 0-10000 ppm . Accuracy specifications are range-dependent: ±40 ppm ±3% of reading for 2000 ppm models, ±50 ppm ±5% of reading for 5000 ppm models, and ±50 ppm ±10% of reading for 10000 ppm models . Response time is 300 seconds (τ63) for 2000 and 5000 ppm ranges, and 120 seconds (τ90) for 10000 ppm models . Additional performance specifications include non-linearity of 16 ppm, temperature dependence of ±8 ppm/°C at 1100 ppm, and pressure dependence of 0.13% of reading per mm Hg .

Universal outputs include field-selectable 4-20 mA current (maximum 500Ω load), 0-5 VDC, or 0-10 VDC voltage output (minimum 500Ω load) to work with virtually any building management controller or programmable logic controller . Power requirements are 16-35 VDC or 19-28 VAC with average consumption of 2W and peak of 3.75W .

The transmitter operates from 32 to 122°F (0 to 50°C) with humidity limits of 10 to 95% RH non-condensing for 2000/5000 ppm models, and 0 to 85% RH non-condensing for 10000 ppm models . It must be mounted vertically with electrical connections pointing downward . A 30-minute warm-up period is required upon powering for the transmitter to adjust to the current CO₂ concentration . The unit is CE approved and weighs 26.24 oz (744 g) .