ROTRONIC HF8 - Manual (Page 28)

E-M-HF8-V2_10
Rotronic AG
Bassersdorf, Switzerland
Document code Unit
HygroFlex HF8 Humidity Temperature
Transmitter: User Guide Instruction Manual
Document Type
Page 28 of 35
Document title
© 2012; Rotronic AG E-M-HF8-V2_10
8.3 Periodic calibration check of the HygroClip 2 probe
Both the Pt 100 RTD temperature sensor used in the HygroClip 2 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 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.
8.4 HF8 probe calibration and adjustment procedures
The HF8 uses two separate steps:
1) Acquisition and capture of calibration points to the memory of the HygroClip 2 probe
2) Adjustment of the probe based on the calibration points present in the probe memory
When the purpose is just to calibrate a HygroClip 2 probe, use only step 1. Up to 2 temperature calibration
points and up to100 humidity calibration points can be held indefinitely in the probe memory. No calibration
point is saved within the HF8 itself. A calibration protocol can be printed with the HW4 software. Either the
HW4 software or the HF8 can be used at any time to delete unwanted calibration points from the probe or
device memory.
Adjustment (step 2) can be carried out at any time after calibration, even several days later. Adjustment is
purely an electronic process based on the data memorized by the probe.
Note: Instructions for using the ROTRONIC calibration devices and humidity standards are provided in
document E-M-CalBasics
8.4.1 Calibration against a reference probe
The HF8 can be used to do a 1-point or multi-point calibration of a probe connected to one of the HF8 probe
inputs against a reference HygroClip 2 probe connected to the other probe input of the HF8.
Expose both the reference probe and the probe to be calibrated to the same environment and wait for full
equilibrium with the environment. In a still air environment, it is highly recommended to provide some
ventilation that is common to both the reference probe and device to be adjusted.
o Press the MENU key and select either “Probe 1” or “Probe 2”. The reference probe is assumed to be
connected to the non-selected input. Press ENTER to activate the Probe 1 or Probe 2 menu item.
o Use the [-] key to select either “Humi Adjust” or “Temp Adjust” (this can be done in any order).
o Press ENTER to confirm and open the next sub-menu. Use the [-] key to select the “Acquire (Ref =
Probe)” menu item and press ENTER to confirm.
o Humi Adjust: the HF8 displays both the current humidity read by the device to be calibrated and the
value provided by the reference probe. Press ENTER to accept the calibration point. Press ENTER to
confirm and save the calibration point to the device memory. The HF8 automatically exits the menu.
o Temp Adjust: the HF8 displays both the current temperature read by the device to be calibrated and
the value provided by the reference probe. Press ENTER to accept the calibration point. Press
ENTER to confirm and save the calibration point to the device memory. The HF8 automatically exits
the menu.
Note: the procedure can be repeated under different conditions so as to accumulate several calibration points
(temperature: maximum 2 points, humidity: maximum 100 points).