High end adjustment – Vaisala HMT310 User Manual

Page 75

Chapter 6 ___________________________________________________ Calibration and Adjustment

VAISALA ________________________________________________________________________ 75

High End Adjustment

After the low end adjustment, insert the probe into the

measurement hole of the high end reference chamber (for example,

NaCl: 75 % RH chamber in the humidity calibrator HMK15, use

the adapter fitting 13.5 mm for HMT314, HMT315, HMT317, and

HMT318). Note that the difference between the two humidity

references must be at least 50% RH.

Let the probe stabilize for at least 30 minutes. You can follow the

stabilization by pressing any key, typing C and pressing Enter.

When stabilized, type the high-end reference value after the

question mark and press Enter.

>crh

RH : 11.25 Ref1 ? c

RH : 11.24 Ref1 ? c

RH : 11.24 Ref1 ? 11.3

Press any key when ready ...

RH : 75.45 Ref2 ? c

RH : 75.57 Ref2 ? c

RH : 75.55 Ref2 ? c

RH : 75.59 Ref2 ? 75.5

OK indicates that the calibration has succeeded.

10. Take the probe out of the reference conditions and replace the

filter. When using the stainless steel filter, take care to tighten the

filter properly, recommended force is 130 Ncm.

11. If needed, record the calibration information (text and date) to the

12. Reset the transmitter by issuing the RESET command. The

transmitter returns to normal mode.