Hach-Lange SI792 P, SI792x P, SI792x P-FF, SI792x P-PA User Manual - Manual (Page 64)

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.
pH
1. Make sure the system is configured for pH
(PRIMARY_VALUE_TYPE = pH).
2. Collect a grab sample and set CAL_SAMPLE_PRD_PH to sample.
The pH value of the sample is stored. After writing, the parameter is
automatically reset to NOP (no operation).
3. Read the parameter CAL_SAMPLE_PRD_PH_STORED_VAL. It
contains the stored value.
4. Measure the grab sample and write the lab value in
CAL_PRODUCT_PH. The device is now calibrated.
CAL_SAMPLE_PRD_PH_STORED_VAL is reset to zero.
Note: Calibration values can also be entered directly in the
CAL_SLOPE_PH and CAL_ZERO_PH parameters.
ORP
1. Make sure the system is configured for ORP
(PRIMARY_VALUE_TYPE = ORP).
2. Collect a grab sample and set CAL_SAMPLE_PRD_ORP to
sample. The ORP value of the sample is stored. After writing, the
parameter is automatically reset to NOP (no operation).
3. Read the parameter CAL_SAMPLE_PRD_ORP_STORED_VAL. It
contains the stored value.
4. Measure the grab sample and write the lab value in
CAL_PRODUCT_ORP. The device is now calibrated.
CAL_SAMPLE_PRD_ORP_STORED_VAL is reset to zero.