BUCHI KjelSampler K-377 - Manual (Page 73)

6 Operation
73 K-375/376/377 Operation Manual, Version B
(screenshot stretched)
Calibration pH electrode
It is recommended to calibrate the electrode
every day before starting sample determinations.
The electrode should be treated according to the
recommendation described in the electrode supple-
mentary sheet.
We recommend replacing the electrode, if it
does not fulfill the following criteria at 25 °C room
temperature anymore:
Slope 95 – 105 %
Zero point pH 6.4 – 7.6
(For pH electrodes other than the ones supplied by
BUCHI, additional criteria might be important.)
NOTE
It is recommended to use buffer solutions pH 4.00
and 7.00. (For a 3 point calibration in addition the
buffer solution for pH 9.21 is recommended.)
Discard buffer solutions after usage. Work with
fresh solutions every day.
Select either a 2 point or a 3 point calibration.
Prepare and specify the buffer solutions and the
temperature of the buffer solutions.
Press START to start the calibration and follow the
instructions on the screen.
Press CHART to switch to the chart-display of the
last calibrations or press HISTORY to view the data
of the last calibrations.
NOTE
A pH electrode should never be stored dry.
If it has been stored dry, regenerate the electrode
in saturated KCl for 24 hours or at least over night
prior to further use. Do not touch the tip of the elec-
trode and do not wipe it with tissue paper or cloth.