Several calibration procedures at different reference humidities confirm the specified tolerances essentially (the literature values for NaCl, K2SO4, K2CO3 and NH4NO3 could be within the specified accuracy in the temperature range between + 5 ° C and + 25 ° C reproduce). The trend is even at very high humidities (range more than 95% RH) to expect a negative offset, but that usually remains limited to (with condensation of the sensor is the displayed value by 98%). Between multiple comparison thermometers and Dewpoint Pro is rarely a deviation of more than 0.2 ° C. Therefore I use this device, among other things for the calibration of automatic weather stations and other moisture meters, provided I have no Psychrometer Assmann or a chilled mirror available. The Dewpoint Pro can keep up surprisingly well with the considerably more expensive instruments in the laboratory (electronically controlled chilled mirror or psychrometer).
If a humidity calibration should be performed with a supersaturated salt solution is essential to ensure that no liquid lands on the sensor, as this will otherwise be destroyed immediately!
Areas of application that I myself have tested: Measurements under laboratory conditions, meteorological measurements with high temporal resolution (especially for boundary layer processes), calibration of other devices.
