Vaisala HMP228 User's Guide download pdf (Page 45)

Chapter 12 ________________________________ Calibration and adjustment of MM70 series probes

VAISALA _______________________________________________________________________ 43

When using Vaisala humidity calibrator HMK15, use the adapter fitting

(13.5 mm hole). Before starting the adjustment mode, take out the screw

covering the calibration button.

Relative humidity adjustment

LiCl-NaCl automatic adjustment

LiCl-NaCl automatic adjustment is a two-point adjustment in reference

humidities of 11.3 % (LiCl) and 75 % (NaCl). You don't have to feed the

reference values, the

MM70 displays the accurate value based on the

measured temperature and the Greenspan table stored into the memory of

the

MM70. Make the adjustment as instructed in the following section 2-

point relative humidity adjustment (select LiCl--NaCl autom. on item 8 and

follow the display instructions).

2-point adjustment

Low humidity references 0 % (Nitrogen)/ 11.3 % (LiCl) and higher

humidity references 75 % (NaCl)/ 97 % (K

) are recommended for

two-point adjustment. Ensure that the difference between the humidity

references is more than 50 %.

Calibration button

(under the screw)

1 2 ... 40 41 42 43 44 45 46 47 48 49 50 ... 56 57

No comments

Vaisala HMP228 User's Guide Page 45