5 Putting into operation
K-375 / K-376 / K-377
Operation Manual, Version E
56
5.9 Installation of the titration sensor
Connect the sensor to the cable already mounted.
Fig. 5.16: Connection of the sensor
5 9 1
Potentiometric sensor
Remove the pH electrode from the storage cap and insert it into the receiving vessel. The spacer is
used to adjust the positioning. The electrode must not touch the bottom of the receiving vessel, as
this could lead to glass breakage. The ideal positioning is 1-2 mm above the bottom of the receiving
vessel.
NOTICE
Risk of sensor damage by pushing the electrode with too much pressure onto the bottom of the
receiving vessel.
Risk of sensor damage by wrong storage.
Always store the pH electrode in the storage cap in saturated KCl solution (4.2 mol/L). A pH elec-
trode should not be stored dry as this would destroy the diaphragm. If a pH electrode has been
stored dry, let it regenerate in saturated KCl for 24 hours or at least overnight prior to further use.
5 9 2
Colorimetric sensor
Fig. 5.17: Colorimetric titration setup
Fit the air bubble trap on the condensate outlet. The wavelength must be adjusted on the optical
sensor according to the indicator (Sher: 610nm, bromocresol/methyl red: 640nm); this can be done
with a permanent magnet (magnetic mixing rod) on the sensor probe. Clean the optical sensor before
use and construct the test setup according to the technical note (335/2018) available on the BUCHI
website.
