The CWE2 Series of air quality sensors for living space are for use with BAS controllers designed to accept 4 to 20 mA, 0 to 5 VDC or 0 to 10 VDC outputs. These sensors measure CO2 levels using a dual-beam, non-dispersive infrared [NDIR] technology. The CWE2 Series Economy sensor has an accuracy of ±30 ppm ±3 Percentage of measured value, features 2-wire 4 to 20 mA and 3-wire voltage outputs, and is available with optional temperature output.