Calibration; Why Calibrate; When To Calibrate; Calibration Standards - wtw inoLab Multi 9620 IDS Operating Manual

Turbidity measurement (VisoTurb
Criteria for a stable
measured value
88
®
900-P)
You can prematurely terminate the Stability control function
manually with <ENTER> at any time. If the Stability control
function is prematurely terminated, the current measure-
ment data are output to the interface without the AutoRead
info.
3. Using <ENTER>, start a further measurement with Stability control.
or
Release the frozen measured value again with <AR>.
The display switches to the measured value display.
The [AR][HOLD] status display disappears.
The Stability control function checks whether the measured values are stable
within the monitored time interval.
Measured param-
eter
Turbidity
(FNU/NTU)
The minimum duration until a measured value is assessed as stable is the mon-
itored time interval. The actual duration is mostly longer.

10.2 Calibration

10.2.1 Why calibrate?

The calibration line of the sensor is determined and stored through calibrating.

10.2.2 When to calibrate?

 When the calibration interval has expired
 At regular intervals

10.2.3 Calibration standards

Calibrate with 1 to 3 turbidity standard solutions. The standard solutions must
be selected in the following order.
Standard solution
1
2
3
The turbidity expected in the measurement dictates the number and selection
of the standards. Calibration has to be carried out for the range with the highest
Time interval
15 seconds
Range (FNU/NTU)
0.0 ... 1.0
5.0 ... 200.0
200.0 ... 4000.0
®
inoLab Multi 9620 IDS
Stability in the time inter-
val
∆ : better than
1.0% of measured value
ba77173e04 12/2017