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<< Click to Display Table of Contents >> Navigation: Humidity & Temperature Devices > Transmitter > HF5 > Maintenance > Periodic calibration check of the probe |
Both the Pt 100 RTD temperature sensor used in the probe and associated electronics are very stable and should not require any calibration after the initial factory adjustment.
Long term stability of the ROTRONIC Hygromer HT-1 humidity sensor is typically better than 1 %RH per year. For maximum accuracy, calibration of the probe should be verified every 6 to 12 months. Applications where the probe is exposed to significant pollution may require more frequent verifications.
Note: the HygroClip2 Advanced probe cannot be adjusted when connected to model HF52 (2-wire circuit type)
Temperature adjustment
The keypad of the HF5 allows only a 1-point adjustment of temperature. The effect of a 1-point temperature adjustment is to add the same offset to all measured values.
•When temperature is stable, press the MENU key to show the internal menu on the display
•Use the (-) key to select Temperature Adjust and press the ENTER key
•Make sure that the text line beginning with RefValue is highlighted and press the ENTER key
•Use the (+) or (-) key to change the reference value to match the temperature reference
•Use the (-) key to highlight the Adjust text line and press the ENTER key
•The HF5 confirms the adjustment with the message “Adjust OK”
•Press the MENU key twice to exit the menu and return the HF5 to normal operation
Notes:
•Any temperature adjustment should be done prior to adjusting humidity.
•The calibration point is automatically deleted from the probe memory after an adjustment
•Because the HF5 has no real time clock, the date of the adjustment is not written to the probe. If retaining the adjustment date is important, use the HW5 or HygroSoft software to adjust the probe.
Humidity adjustment
The keypad of the HF5 allows a multi-point adjustment of humidity. The effect of a humidity adjustment depends on the number of calibration points present in the probe memory prior to the adjustment:
•one calibration point: offset added to all measured values
•two calibration points: offset and slope
•three or more calibration points: offset, slope, linearity
For maximum accuracy use at least 3 to 4 calibration points distributed equally across the measurement range of interest. The calibration points (maximum 100) can be acquired in any order but we recommend going from low humidity values to high humidity values.
•When humidity is stable, press the MENU key to show the internal menu on the display
•Use the (-) key to select Humidity Adjust and press the ENTER key
•Make sure that the text line beginning with RefValue is highlighted and press the ENTER key
•Use the (+) or (-) key to change the reference value to match the reference humidity
•Use the (-) key to highlight the Acquire text line and press the ENTER key
•Note that the “Acquired” counter is incremented by 1 (number of calibration points in the probe memory)
•When all calibration points have been acquired, use the (-) key to highlight the Adjust text line and press the ENTER key. Do not adjust the probe before having acquired all calibration points.
•The HF5 confirms the adjustment with the message “Adjust OK”
•Press the MENU key twice to exit the menu and return the HF5 to normal operation
Notes:
•All calibration points are automatically deleted from the probe memory after an adjustment
•Instructions for using the ROTRONIC calibration devices and humidity standards are provided in document E-M-CalBasics.
•Because the HF5 has no real time clock, the date of the adjustment is not written to the probe. If retaining the adjustment date is important, use the HW5 or HygroSoft software to adjust the probe.