Rotronic CP11 Portable Indoor Air Quality Monitor. The Rotronic CP11 handheld instrument is the latest development of an economical multiple parameter meter which simultaneously measures and records CO 2 , humidity and temperature. It also calculates the dew point and wet bulb temperature, and is equipped with the field-tested Rotronic Hygromer® IN-1 humidity sensor. Using the ROTRONIC HW4-Light software that comes with the device, the CP11 can be set as required and data can be downloaded, saved and analyzed. Power supply is by AA (x4) batteries. CP11 applications include indoor air quality, monitoring in underground car parks (safety) and leak monitoring in filling plants (safety). Measures and logs CO 2 , relative humidity and temperature Calculates the dew point Hygromer® IN-1 humidity sensor 18,000 data point memory for CO 2 , humidity and temperature values Maximum, minimum and average value display Adjustable audible CO 2 alarm Display with backlight Adjustable auto power off function Mini USB interface