The TQC DewCheck 4 - Dewpoint Meter (DPM)/ Dewmeter is an extremely versatile dewpoint meter to measure and record all climate parameters required to treat surfaces. This easy to use and robust dewmeter conforms to ISO 8502-4 & ASTM D3276-07 and measures the relative humidity (%RH), ambient temperature (Ta) and surface temperature (Ts) and calculates the dewpoint temperature (Td) and the difference between the dewpoint temperature and the surface temperature (ÄT). The difference between the surface temperature and dewpoint temperature indicates the optimal climate conditions for painting. All parameters can be stored in the dewmeter's memory, tagged with a date and time.