Thermo orion 135A, Instruction Manual

Page: 19 / 56

Note
cal
Models 135A and 136S Portable Conductivity Meters
Operation 13
Calibration with 0.1 or 0.01 molar KCl solution (AutCAL On)
(Thermo Orion 12.9 mS or 1413
m
S Conductivity Standard)
Impurities must always be prevented from getting into the
calibration solutions.
Pressing the
cal
key activates calibration.
Calibration can be cancelled by pressing the
meas
key.
Then the cell constant of the last calibration is displayed
briefly.
Select the calibration solution used (CALSoL). A 0.1 and a
0.01 molar KCl solution are available to choose from. Con-
firm the corresponding solution with the
cal
key.
Immerse the clean and dry sensor in the calibration solu-
tion (also see “Clean sensors”, Pg. 11).
Press the
cal
key to start calibration. If calibration is not
desired, cancel the process with the
meas
key.
During calibration the lower line indicates the temperature.
The automatic drift check checks the stability of conductiv-
ity and temperature. The hour glass flashes.
When the measured values are stable, the temperature-
compensated table value of the KCl solution is displayed.
The measured conductivity value flashes.
Confirm with the
cal
key.
The determined cell constant is displayed for a few se-
conds. Then the meter switches back into the measuring
mode.