Replacing the HUMICAP® sensor - HMP1 - HMP3 - HMP4 - HMP5 - HMP7 - HMP8 - HMP9 - HMPX - MMP8 - MMPX - TMP1 - TMPX

HMP Series with MMP8 and TMP1 User Guide
Document code
M212022EN
Revision
K
Language
English
Product
HMP1
HMP3
HMP4
HMP5
HMP7
HMP8
HMP9
HMPX
MMP8
MMPX
TMP1
TMPX
Document type
User guide
  • New HUMICAP® R2 sensor
  • New compatible filter
  • Clean lint-free gloves
  • 11.3 %RH and 75.5 %RH humidity references (using Vaisala HMK15 Humidity Calibrator), or other humidity references of your choice
  • Computer with a Microsoft Windows® operating system (64-bit version) and Vaisala Insight PC software installed

  • Indigo USB adapter (item code USB2) or USB connection cable (item code 242659)

Follow this procedure to replace a HUMICAP® R2 humidity sensor if it has been damaged, or normal adjustment is not sufficient to restore the humidity measurement accuracy. It is recommended that you replace the filter at the same time. The procedure includes a special 2-point adjustment of humidity measurement using the Insight PC software. This RH adjustment for new sensor must be done every time after the HUMICAP® R2 sensor has been replaced.

Of the humidity sensors available in HMP series probes, only HUMICAP® R2 sensors are designed to be replaced by the user. If you need to replace another type of humidity sensor, such as a composite sensor, contact a Vaisala Service Center.

CAUTION Sensors are easily damaged when the filter is not in place. Handle the probe head carefully.
Figure 1. Example: HMP3 probe head with filter removed
1
Pt100 temperature sensor
2
HUMICAP® R2 humidity sensor
  1. Put on clean gloves before touching the filter.
  2. Turn the filter counter-clockwise to loosen it.
  3. Remove the filter from the probe head. Be careful not to touch the sensors with the filter.
  4. There are two sensors under the filter, the HUMICAP® sensor and a temperature sensor. Identify the HUMICAP® sensor and make sure it is of the type that you can replace yourself (temperature sensor not attached to it).
  5. Pull out the old HUMICAP® sensor and insert the new one.
    CAUTION Handle the new sensor by the plastic frame. Do not touch the sensor element in the middle of the sensor. Do not touch the temperature sensor.
  6. Open the Insight software on your PC.
  7. Select Settings > Advanced mode.
  8. Connect the probe to the Insight software.
  9. Select > Calibrate > Yes to switch the probe to calibration mode.

    In calibration mode, the device will not use functions that may interfere with calibration and adjustment.

  10. Select RH adjustment for new sensor.
  11. Adjust the 11.3 %RH point (dry end):
    1. Insert the probe head in the 11.3 %RH reference.
    2. Wait for the measurement to stabilize fully.
    3. When the measurement has stabilized, click the Reference value, point 1 field and enter the RH level of the first reference point (11.3). Press ENTER or click outside the field when done.
    4. The probe automatically enters the measured temperature value for the calibration point.
  12. Adjust the 75.5 %RH point (wet end):
    1. Insert the probe head in the 75.5 %RH reference.
    2. Wait for the measurement to stabilize fully.
    3. When the measurement has stabilized, click the Reference value, point 2 field and enter the RH level of the second reference point (75.5). Press ENTER or click outside the field when done.
    4. The probe automatically enters the measured temperature value for the calibration point.
  13. To save the adjustment into the device, select Overwrite factory adjustment.
  14. Remove the probe head from the calibration reference and install a new filter. Tighten the filter properly (recommended force 5 Nm).
  15. Select the Calibration information tab and update the Calibration date and Calibration text.
  16. Select Close to exit the calibration mode.