NovaLynx Corporation
225-HMP60x
Page 7
February 2021
The sensor elements are protected by a removable cap/filter. The cap can be replaced if the filter is
dirty. The humidity sensor chip is replaceable. The chip is factory-trimmed so that there is no need to
calibrate after replacing the part. The temperature sensing element is a separate part and is not user-
serviceable.
Note: Unscrew counter-clockwise to remove the cap.
The base of the probe is connected to the cable by an M8 connector.
Note: The connection may be
covered by heat shrink tubing.
The probe may be disconnected and returned to NovaLynx for a
calibration check, or the entire probe, cable and sunshield can be returned for service or a calibration
check. If only the probe is to be returned, inspect the cable carefully to ensure it is not the cause of any
problems you may have experienced with the sensor.
7
CALIBRATION TEST KIT
The NovaLynx
220-HMK15 Humidity Calibrator
(sold separately) is available for checking the
calibration of electronic RH sensors by the user. The calibrator includes two chambers with saturated
salt solutions to test the sensor at 12% and 75% RH. Testing at two points verifies the overall operating
range of the humidity sensor. Spot checking at ambient conditions may not always detect a marginally
defective sensing element.
The calibration chambers work best in stable temperature conditions (indoors), but can also be used to
make quick and accurate field tests. In either case, the chamber humidity reading is corrected
according to the temperature indicated on a built-in thermometer. Sensor readings can be taken
within 5 minutes.
8
TROUBLESHOOTING
If the sensor’s output signal appears to be in error or is absent, check the power connections. At the
sensor cable, measure the input power source voltage with a voltmeter. Check each signal output by
disconnecting the signal wire from the monitoring equipment and then measure the output voltage.
