Decrease quantity for Siemens QPA2000 Room CO2 Sensor - Full Feature, 0…10V, 0…2000ppm; Accuracy ?± 50 ppm + 2 % of measured value Quantity Increase quantity for Siemens QPA2000 Room CO2 Sensor - Full Feature, 0…10V, 0…2000ppm; Accuracy ?± 50 ppm + 2 % of measured value Add to cart