
7
Operation
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User qualification, operation: instructed user
‘User qualification’ on page 7
7.1 Calibrating the DULCO turb C
INFORMATION: The DULCO turb C has been tested and the
measuring range of 0...100 NTU has been calibrated before
leaving the factory. You can therefore use the DULCO turb C
immediately. Under normal conditions, calibration at least once
every 3 months is recommended.
EPA and ISO recommend calibrating the DULCO turb C with a pri‐
mary standard at least every 3 months if the DULCO turb C is to be
used for reporting purposes.
The relay contacts and the 4 ... 20 mA output are frozen when the
device is in calibration mode. In calibration mode, the device has a
timeout function that automatically allows the system operation to
return to AUTO mode after 15 minutes of inactivity.
7.1.1 Standard solutions (0 ... 100 NTU range)
INFORMATION! If the sensor is operated over its complete meas‐
uring range of 0.02 NTU ... 1000 NTU, then you need to perform
full calibration with all 3 standard solutions (0.02 NTU, 10.0 NTU
and 1000 NTU). If the sensor is only operated in measuring ranges
below 10 NTU, then simplified calibration with the standard solu‐
tions 0.02 NTU and 10.0 NTU can be performed.
Calibration set order number: 1037699
7.1.2 Other measuring ranges
If the range of the factory setting 0 ... 100 NTU is changed, then
the device needs to be recalibrated.
The calibration values are 10 NTU, 1 NTU and 0.02 NTU for the
range 0 ... 10 NTU. The device asks you for the corresponding
standard solutions.
The calibration values are 1000 NTU, 10 NTU and 0.02 NTU for
the 0 ... 1000 NTU range. The device asks you for the corre‐
sponding standard solutions.
Calibration kits are available for the optional ranges.
If necessary, modify the instructions in Section 4.3.3 below.
Before recalibrating, check the expiry dates to ensure that the
standard solutions have not passed their best before date.
Operation
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