Siemens QPM2100 Duct Air Quality Sensor,
The QPM Series Duct CO2 Sensors monitor and transmit
changes in CO2 to the building control systems. Several
models are available for CO2 only, CO2/Temp, CO2/Temp/
RH and CO2/VOC. All variants for CO2 and combination
versions with Temperature or Volatile Organic Compounds
(VOCs) deliver 0 to 10 Volt to 5 Volt (field selectable)
proportional signals to the controller.
No calibration of the CO2 sensor is necessary – these
microprocessor-based units consist of an NDIR sensor
that experiences less than 1% drift per year for the first
two years of operation and negligible drift thereafter.

