ROTRONIC HP21 - Manual (Page 10)

E-M-HP21-V1_21
Rotronic AG
Bassersdorf, Switzerland
Document code Unit
HygroPalm HP21 hand-held indicator:
User Guide Instruction Manual
Document Type
Page 10 of 14
Document title
© 2009-2010; Rotronic AG E-M-HP21-V1_21
5.3 Periodic calibration check
Both the Pt 100 RTD temperature sensor 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 HP21 should be verified every 6 to 12 months. Applications
where the HP21 is exposed to significant pollution may require more frequent verifications.
a) Procedure for adjusting the HP21 from the keypad
The keypad of the HP21 allows a 1-point adjustment of temperature or humidity against a reference.
A 1-point adjustment has the effect of adding the same offset to all measured values. A multi-point
adjustment is not possible from the keypad and requires using either a PC with the HW4 software
installed or the HP23 hand-held calibrator.
When the parameter to be adjusted is stable, press the MENU key to show the internal menu on the
display
Use the DOWN key to select either H-Adjust or T-Adjust and press the ENTER key
Make sure that the text line beginning with RefValue is highlighted and press the ENTER key
Use the UP or DOWN key to change the reference value as desired
Use the DOWN key to highlight the Adjust text line and press the ENTER key
The HP21 confirms the adjustment with the message “Adjust OK”
Press the MENU key twice to exit the menu and return the HP21 to normal operation
Notes:
o
The calibration point is automatically deleted from the probe memory after an adjustment
o Instructions for using the ROTRONIC calibration devices and humidity standards are provided in
document E-M-CalBasics
o Because the HP21 has no real time clock, the date of the adjustment is not written to the HP21. If
retaining the adjustment date is important, use the HW4 software to adjust the HP21.
b) Procedure for adjusting the HP21 with the ROTRONIC HW4 software:
Use cable AC3006 to connect the service connector of the HP21 to the USB port of a PC with the
ROTRONIC HW4 software installed. Note that the ROTRONIC USB driver must be installed on the
PC as explained in the HW4 manual E-M-HW4v3-Main
Start HW4 on the PC and search for the HP21(HW4 Main Menu Bar > Devices and Groups > Search
for USB Masters).
After finding the HP21 with HW4, expand the device tree to see the HP21 functions.
Select Probe Adjustment.
For further instructions see HW4 manual E-M-HW4v3-A2-001