JUMO 202550 Operating Instructions Manual page 56

18 Conductivity indicator
18.7.2 Automatic determination of the relative cell constant with a
reference instrument
You will need
Initial condition
Procedure
54
"Unlocking the levels", page 27, (code word 0110)
Immerse the sensitive portions of the cell and the temperature probe or
thermometer in the calibration solution
– wait until the temperature and conductivity measurements have
stabilized.
Press the and
PGM
alternating with the measured or manually set temperature.
Use the and
conductivity of the calibration solution at the temperature now prevailing.
Press the key (saves the new cell constant and returns to the
PGM
measurement mode).
If the deviation of the cell constant from its nominal value is not known, then it
can be automatically determined.
A conductivity measuring instrument to serve as a reference.
The temperature coefficient of the reference instrument must be set
to "0" ! If this is not possible, then the solution being measured must
be tempered to the reference temperature for the reference
instrument.
The conductivity transmitter is connected to the JUMO dTRANS Az 01
Chapter 18.1 "Conductivity measurement circuit", page 48ff.
The calibration procedure has been configured to "Calibration of the cell
constant, process value output ..." – frozen or not frozen,
Chapter 26.4 "Controller options - C211", page 76.
The instrument is in the measurement mode,
"Operating modes and states", page 24.
Unlock the instrument for calibration,
"Unlocking the levels", page 27, (code word 0110)
Immerse the sensitive portions of both cells in the calibration solution
– wait until the measurements for both instruments have stabilized.
Press the and
PGM
lower display, alternating with the measured or manually input temperature.
Use the and
value shown on the reference instrument.
Press the key (saves the new cell constant and returns to the
PGM
measurement mode).
keys – "CAL.1" appears in the lower display,
keys to set the indicated conductivity to the real
keys on the instrument – "CAL.1" appears in the
keys to set the indicated conductivity to match the