Hygrometers are simple instruments specifically designed to provide climatic parameters relevant to the application of a coating. The key climatic parameters that can be recorded with a hygrometer include Delta T (TΔ), relative humidity (%RH), dewpoint and surface temperature (Ts) critical in hot climates.
Elcometer offers a range of hygrometers from manual and analogue hygrometers which with the use of dewpoint calculator provide the dewpoint and relative humidity values; to very accurate digital hygrometers which automatically record all the measurements and perform calculations of the climatic conditions.
The manual hygrometers, such as the Elcometer 116A Whirling Hygrometer, are often used to measure wet bulb (Twb) and dry bulb (Tdb) temperatures which can then be used to determine the relative humidity (RH).
The manual hygrometer consists of two thermometers, one of which has the bulb wrapped in muslin. The muslin is wetted with distilled water, and the hygrometer is whirled around at a defined speed and duration. The dewpoint parameters can then be easily calculated using the dewpoint calculator.
Instead of using hygrometers conversion disks and charts there are gauges on the market, such as the Elcometer 308 & Elcometer 309, which will instantly take all the measurements and perform all the calculations.
The digital hygrometers are more accurate and reliable and allow users to take various and repetitive measurements to monitor the climatic conditions during a period of time. The Elcometer 308 Digital Hygrometer provides the surface temperature and relative humidity, whereas the Elcometer 309 Delta T Hygrometer measures Delta T - the difference between the surface temperature and the dewpoint temperature, and relative humidity.