Special Notes Concerning Ise Electrodes During Ph Calibration - palintest Macro 900 Operation Manual

Macro 900 Operation Manual
5. During long term deployment of ion selective electrodes, the user should
obtain grab samples during the course of the deployment for analysis in the
laboratory by chemical means and use the results to apply post calibration to
the recorded results.
6. Accuracy in the field is dependent upon full three-point calibration and
minimal time between calibration and use.
7. In order to achieve accurate readings with ISE electrodes, the Probe needs
to be either placed in flowing water, or needs to be stirred or raised and
lowered continuously to ensure a minimum flow rate of 0.3m/s over the
electrode. If there is no water flow across the ISE electrode, the ions
in the immediate area of the electrode will be depleted and the
reading will start to fall. This also applies to calibration, where the
probe should be stirred at all times.

26.1. Special Notes Concerning ISE Electrodes during pH Calibration

The high ionic concentration of pH
calibration solutions (buffers), including
MacroCal, can cause significant offsets in
ISE electrodes.
These offsets are temporary, but best
avoided because they can cause
significant errors during both calibration
and normal operation.
For this reason all ISE electrodes are
supplied with a red rubber sealing cap.
The caps should be fitted to all ISE
Electrodes during pH calibration or
when using MacroCal
of the buffer solution.
At all other times, the ISE electrodes should be left uncovered.
© 2013 Palintest Ltd.
in order to protect the ISE electrodes from the effects
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