The Testo 0636 9835 Standard Pressure Dewpoint Probe guarantees quick and accurate dew point measurement. The probe is sufficient for most measurements in compressed-air piping (e.g. refrigeration dryers in the range from 0 to 2 degrees C tpd). By connecting the probe to the Testo 635-1 or 635-2 (available separately), the user has a portable, mains-independent measuring system. The large display on the measuring instrument enables the display of the relative humidity or the dew point with the temperature.The probe is connected to the compressed air system via a standard plug-in connector (G1/4" internal thread to ISO 228-1) or via a screw-on adapter for measurements at test points. If required other standard plug-in connectors with thread G 1/4" can be screwed into measuring chamber