In Process Calibration; Sample Collection - ABB Aztec ATS430 Operating Instructions Manual

6.4.4 In process calibration

In process calibration is used when it is not possible to remove
the sensor from the process to perform the calibration. In this
calibration mode the actual sample is used to calibrate the
sensor.
The in process calibration takes place in two steps. During the
first step a grab sample is taken from the process, and the
sensor records the turbidity of the sample at that time. The
suspended solids content of the grab sample is then measured
in the laboratory and entered into the transmitter during the
second step.
Due to the inherent variability of both the turbidity and
suspended solids measurements, using a single point to
calibrate the suspended solids measurement can lead to sudden
jumps in the suspended solids value reported by the sensor.
(The ATS430 sensor supports an adaptive calibration mode,
which mitigates the occurrence of such jumps.) – refer to
AN/ANAINST/021-EN for details of adaptive calibration.
1. At the Calibration Type screen, use the
select Sample Collection and press the
OK prompt):
Calibration Type
1-Point Cal
2-Point Cal

Sample Collection

Collection Complete
Manual Coefficient
Cancel
2. Proceed to Section 6.4.5 (Sample collection) to start the
first part of the calibration.
20 OI/ATS430–EN Rev. H | Aztec ATS430 | Turbidity sensor
/ keys to
key (below the
OK
6.4.5 Sample collection
1. This is the first step of the calibration. On the next screen,
press the key (below the Next prompt).
Performing this step erases any sample collection
performed previously. Only the last sample collection
performed is stored in the sensor.
Collect Sample
Start Collection?
Abort
2. On the following screen press the
Continue prompt) to start the data collection. The grab
sample should be taken as close to the sensor as possible
during this period.
The calibration process screen is displayed – the acquisition
can be cancelled at any time during the process by pressing
the key (below the Abort prompt):
Collect Sample
PV 0.000 mg/l
NTU 2000 NTU
Settling-Please Wait
Abort
3. Once the acquisition is complete, Press the
the Exit prompt) to return to the main menu.
Collect Sample
PV 0.000 mg/l
NTU 2000 NTU
Procedure Complete
Exit
The value of the sample turbidity is now stored.
4. Proceed to Section 6.4.6 (Sample collection) to start the
second part of the calibration once the suspended solids
value has been determined.
Continue
key (below the
key (below