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RH390: Precision Psychrometer

Highest 2% RH accuracy with fast 30 seconds Response Time

View Datasheet > RH390


Measure humidity and temperature simultaneously with the RH390 Precision Psychrometer from Extech. A dual-illuminated readout can be alternated to display wet bulb and humidity, or dew point and humidity, or temperature and humidity. This handheld device registers temperatures from -22 degrees to 199 degrees F (-30 degrees to 100 degrees C) and measures the full spectrum of relative humidity with ±2% accuracy between 20 and 90% RH. 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)


7.8×1.7×1.3" (200x45x33mm)


7oz (200g)

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