ProMinent DULCO turb C Series, Руководство по сборке и эксплуатации, Страница: 42 / 76

In certain circumstances it may be desirable to use an offset function in order to
balance the device, instead of performing a complete calibration (as described
under
Ä
Chapter 7.1 „Calibrate sensor“ on page 55). This procedure is not rec‐
ommended as a replacement for regular calibration, however, it can be used in
order to compensate for known minor deviations where measuring operations
cannot be interrupted. This balancing method means that the device only dis‐
plays precise turbidity values in the immediate vicinity of the sample value and
not across the entire measured range.
Proceed as follows in order to configure the offset:
1.
Take a sample of the process water being monitored by the device and
make a note of the turbidity as indicated by the device.
2. Measure the turbidity value of the sample with the help of a calibrated
manual laboratory measuring device (reference device)
3. Compare the turbidity value indicated by the device with the value meas‐
ured by the reference device. If the values are extremely close to each
other (depending on the accuracy of the reference device), then no offset
configuration or calibration is required and the procedure can be aborted
at this point.
ð
However, if the values differ significantly (however, less than 1 NTU),
then proceed as follows in order to improve the turbidity value for the
device, so that the device matches the laboratory value.
4. Select the offset function by pressing
[MODE/EXIT button] until the arrow
is positioned next to
[CONFIG]
5. Press the key ↲, until
[OFST] is shown in the lower row
ð
At this point, the upper row of the display indicates the operating con‐
dition of the offset function.
6. If the function is switched off, then switch it
[ON] , by pressing ▼ or ▲ .
7. Select the desired offset value with ▼ or ▲
ð
Press the key ↲, to accept the value.
Commissioning
42