2-point adjustment of HMT330/PTU300 using a calibrator - HMT330 - PTU300 - HM70

HM70 User Guide

Document code
M210297EN
Revision
G
Language
English (United States)
Product
HM70
Document type
User guide
This procedure is 1 of the alternative methods for completing the adjustment described in Calibrating and adjusting HMT330 series and PTU300 series transmitters.

The difference between the 2 reference humidities must be at least 50 %RH.

The MI70 indicator is used now only as a terminal for visualizing and setting the transmitter's RH reading.

If you use Vaisala Humidity Calibrator HMK15, use the adapter fitting (13.5 mm) on the measurement hole if you calibrate probes of HMT334, HMT335, HMT337, or HMT338 transmitter models.

To complete the adjustment:
  1. Remove the filter from the transmitter's probe and insert the probe into the lower reference humidity.
  2. Press Adjust to continue adjusting.
  3. Select 2-point adjustment and press Select.
  4. Press Ready when the reading has stabilized in the first reference condition (note that the stabilization may require 30 minutes or longer). You can follow the stabilization from the graphical display by pressing Graph.
  5. Enter the correct lower reference value with the arrow buttons and press OK.
  6. Remove the probe from the lower reference and insert the probe into the higher reference.
  7. Press Ready when the reading has stabilized in the second reference condition (note that the stabilization may require 30 minutes or longer). You can follow the stabilization from the graphical display by pressing Graph.
  8. Enter the correct higher reference value with the arrow buttons and press OK.
  9. Confirm the adjustment by pressing Yes. If you press No, you return to the adjustment mode display and no changes are made.
    If the difference between 2 references is less than 50 %RH, the adjustment cannot be done.
  10. The adjustment is done. Press Back and Exit to return to the basic display.