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RH490: Precision Hygro-Thermometer

Highest 2% RH accuracy with Grains Per Pound (GPP) Display

View Datasheet > RH490


Anyone whose job relies on calculating humidity levels will appreciate the Extech Hygro-Psychrometer. In addition to measuring relative humidity in 30 seconds, this handheld instrument captures dew point, wet bulb, temperature and water vapor levels (Grams per Kilogram and Grains per Pound). This utility tool will store maximum and minimum readings until the memory is cleared and includes a data-hold button for rapidly fluctuating measurements. Complete with carrying case and 9V battery.

Additional information


0 to 100%RH

Temperature (Internal)

-22 to 199°F (-30 to 100°C)

Basic Accuracy

±2%RH, ±1.8°F/1°C

Max. Resolution

0.1%RH, 0.1°F/°C


-22 to 199°F (-30 to 100°C)

Absolute Humidity

0 to 1120GPP (0 to 160g/kg)


7.8×1.7×1.3" (200x45x33mm)


7oz (200g)

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