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Operating Range: -20ºC to +80ºC
Air Temperature (TΔ): -20ºC to +80ºC
Surface Temperature (TS): -20ºC to +80ºC
Relative Humidity (RH) & Accuracy: 0% to 100% RH (±3%) (Default upper limit 75%, user adjustable)
Resolution: 0.1ºC (0.1ºF) / 0.1%
Power Supply: 2 x AA 1.5V Batteries or via USB Cable
Battery Life: Greater than 40 hours (Backlight off)
Dimensions: 180 x 75 x 35mm
Weight: 300g
Packing List: Elcometer 309 Delta T Hygrometer, wrist strap, 2 x AA batteries, protective pouch with belt clip, RH probe calibration certificate and operating instructions
Delta T (TΔ) is the difference between the surface temperature (Ts) and the dewpoint temperature (Td). When TΔ is less than 3ºC (5ºF) painting should not occur.
Relative Humidity (RH) - expressed as a percentage, RH is the ratio of the amount of water vapour actually held by the air compared to the maximum amount of water vapour the air could hold at a given temperature. Typical maximum RH values specified by paint manufacturers are between 75% and 85%.
The Elcometer 309 Delta T Hygrometer key features include:
