Testo 625 thermo hygrometer testo 0563 6251 p this compact thermohygrometer from testo has a connectable humidity sensor which measures the air temperature and relative humidity it can also calculate the dew point and wet bulb temperature the meter is equipped with a large easy to read backlit display a hold function which allows you to freeze the last reading and min and max readings that can be displayed at the touch of a key p p it is ideal for monitoring production and storage con