Testing a RH5 or RH5X Relative Humidity Sensor
- 12V battery
- Digital voltmeter (DVM)
The RH-5X will run on an excitation voltage from 10 to 36 V DC and will typically draw about 1.2 mA of current.
Connect a 12V battery in series with a current meter to power the RH-5X black (-) and red (+) leads. If the current is higher than 2.5mA, something is wrong and the sensor should be replaced.
Signal Output Check:
- Power the RH-5X with the 12 V battery connected to the black (-) and red (+) leads.
- Read the output voltage between the black (-) and signal (clear) leads. The reading must be between 0 and 5 volts. If the reading is greater than 5 volts, there is a problem.
- Allow sufficient settling time (sometimes several minutes are required) for the reference hygrometer and try to place it's probe as close as possible to the RH-5X.
- Convert that voltage into a relative humidity (using the formula below) and compare against a reference hygrometer.
- Relative Humidity = V out x 20
- If the RH-5X is within 3 percent of the reference, it is good.
- An output reading of 3.76 Volts is taken across the black and clear leads.
- Relative Humidity = 3.76 x 20
- Relative Humidity = 75.2 percent
Download Calibration Reports
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BP20 Barometric Pressure Sensor
Windsensor P2546-OPR Anemometers
NRG Class 1 Anemometer
Thies First Class Advanced Anemometer
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