Product Description: The testo 635-2 temperature and moisture meter is excellently equipped for carrying out a variety of measurements in the field of air conditioning. A wide selection of optionally available sensors and probes can be connected to the meter to provide you with the following measuring data:  Relative humidity  Material moisture  Material compensation moisture  Pressure dew point in compressed air systems  HTC value  Air temperature  Surface temperature  Core temperature  Absolute pressure Two sensor ports for pluggable sensors; up to 3 further temperature or moisture sensors which can be connected via wireless with the temperature and moisture meter. The results are presented on the easy-to-read display. Your meter can be upgraded with an optionally available plug-in type wireless module which can transmit a wireless signal over a distance of up to 20 meters. Technical Data             Temperature - NTC          Measuring range    -40 to +150 °C        Accuracy    ±0.2 °C (-25 to +74.9 °C) ±0.4 °C (-40 to -25.1 °C) ±0.4 °C (+75 to +99.9 °C) ±0.5 % of mv (Remaining Range)        Resolution    0.1 °C           Temperature - TC Type K (NiCr-Ni)          Measuring range    -200 to +1370 °C        Accuracy    ±0.3 °C (-60 to +60 °C) ±(0.2 °C + 0.5 % of mv) (Remaining Range)        Resolution    0.1 °C           Humidity - Capacitive          Measuring range    0 to +100 %RH        Accuracy    See probe data        Resolution    0.1 %RH           Absolute Pressure          Measuring range    0 to 2000 hPa        Accuracy    See probe data        Resolution    0.1 hPa           General technical data          Weight    428 g        Dimensions    220 x 74 x 46 mm        Operating temperature    -20 to +50 °C        Product-/housing material    ABS / TPE / Metal        Battery type    Alkali manganese, mignon, type AA        Battery life    200 h        Storage temperature    -30 to +70 °C