Chapter 5 ______________________________________________________________ MaintenanceVAISALA _______________________________________________________________________ 55Changing the HUMICAP® 180R Sensor(HMP110)NOTE Replacing the humidity sensor of the HMP110 is not necessary innormal operation. If the accuracy of the probe does not seem to bewithin specification, it is likely that the accuracy can be restored byperforming the adjustment procedure. See section Two-PointAdjustment of RH Measurement (HMP110) on page 50.Follow this procedure to replace the humidity sensor of the HMP110 incase it has been damaged, or normal adjustment is not sufficient torestore the measurement accuracy. Calibration and adjustment of thehumidity measurement is required after the sensor change.To perform this procedure, you need a new HUMICAP® 180R sensor. Itis also recommended that you replace the filter with a new one. Fororder codes, see section Options and Accessories on page 62.1. Remove the filter from the probe by turning it counter-clockwise.2. Pull out the old HUMICAP® 180R sensor (the taller of the twosensors inside the probe) and insert a new one. Refer to Figure 17on page 54. Handle the new sensor by the plastic frame. DO NOTTOUCH THE SENSOR PLATE.3. Perform a two-point adjustment of the RH measurement asinstructed in section Two-Point Adjustment of RH Measurement(HMP110) on page 50.4. Attach a new filter on the probe.
