Process Unit 73 LF - Knick

6 Calibration
Why do you have to calibrate?
Every cell has its individual cell constant. Depending
on the cell construction, the cell constant
can vary over a broad range. Since the conductivity
value is calculated from measured conductance
and cell constant, the Process Unit 73 LF must
know the cell constant.
For calibration or cell standardization, you either
enter the known cell constant of the cell in
use (printed on the cell) into the Process Unit 73
LF, or automatically determine the constant by
measuring a calibration solution of known conductivity.
Without calibration, every conductivity meter delivers
a wrong output value!
Especially after replacing the cell, you should perform
a calibration if the difference between the cell
constants of the two cells is too high for the required
accuracy.
Monitoring Functions for Calibration
The Process Unit 73 LF provides comprehensive
functions for monitoring correct calibration performance
and sensor state. This allows documentation
for quality management to ISO 9000 and GLP/
GMP.
The logbook provides time and date stamped
records of calibrations performed within the last
200 events. (See page 3–3.)
For the cell constant, you can define limits for a
warning and a failure message. (See page
9–28.) This permits automatic monitoring of the
cell constant value determined during calibration.
Calibration 6–1