Hach-Lange SI792 D, SI792x D, SI792x D-FF, SI792x D-PA User Manual - Manual (Page 65)

Operation—Foundation Fieldbus
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6.2.4 Calibration via Foundation Fieldbus
The transmitter can be calibrated via Foundation Fieldbus using the
comparison or grab sample method.
1. Make sure the system is configured for the value that is measured:
• Dissolved oxygen:
PRIMARY_VALUE_TYPE = DO_mg/l, DO_ppm, DO_µg/l,
DO_ppb or DO_%
APPLICATION = Dissolved oxygen
CALIBRATION_MODE = Conc or Sat
• Gaseous oxygen:
PRIMARY_VALUE_TYPE = GAS_ppm or GAS_%
APPLICATION = Measurement in gases
CALIBRATION_MODE = Conc or Sat
2. Collect a grab sample and set CAL_SAMPLE_PRD to sample. The
measured value of the sample is stored. After writing, the parameter
is automatically reset to NOP (no operation).
3. Read the parameter CAL_SAMPLE_PRD_STORED_VAL. It
contains the stored value.
4. Measure the grab sample and write the lab value in
CAL_PRODUCT. The device is now calibrated.
CAL_SAMPLE_PRD_STORED_VAL is reset to zero.
Note: The calibration values can also be entered directly in the
parameters CAL_ZERO and CAL_HIGH.