Hach-Lange SI792 D, SI792x D, SI792x D-FF, SI792x D-PA User Manual - Manual (Page 75)

Calibration
73
8.1.2 DO calibration (default)
Make sure that DO is selected in the configuration menu ( Table 9 on
page 36 ). For a 2-point calibration, calibrate the zero point first
( section 8.1.1 on page 72 ).
8.1.2.1 Calibration in air (recommended)
1. Press
CAL , enter passcode: 1100, ENTER . The display will briefly
show CAL and then the entered (or default) humidity value.
2. Remove the sensor from the process and place in air.
3. Enter the actual relative humidity and press
ENTER . The display will
show the entered (or default) barometric pressure.
4. Enter the barometric pressure and press ENTER . A drift check will
begin. The drift check may take some time. When complete, the
display will show the concentration in the units specified in the
configuration menu.
Note: To exit the drift check after, 10 seconds, press
CAL (accuracy
will be reduced).
5. Accept the calculated value for the concentration or adjust the value
as necessary and then press ENTER . The display will show the new
slope and zero (relative to 25 °C and 1.013 mbar).
6. Press ENTER to end the calibration. Return the sensor to the
process. The measured value will be shown in the display
alternately with Hold.
7. Press ENTER to return to the measure mode.