SENTRON SI400 7400-0, Руководство пользователя

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6.3 Bias setting
In certain exceptional cases it may happen that the pH measured by the Sentron ISFET pH sensor differs
from a glass pH electrode by a constant pH value. This difference occurs under certain circumstances
and is an inherent physical property of the two different ways pH is measured by a glass or solid state
electrode.
The offset is often seen in comparison measurements between Glass and ISFET, particularly in lactose
products. Although both probes are calibrated at the same buffer fluid (simultaneously), the readout
in the sample material may differ slightly.
To compensate this difference, an offset (bias) can be set so that the measurement values are the
same. This setting can be done at either the glass electrode side or, when the glass measurement
equipment has only limited functions, at the SI meter.
Note that with a fixed offset, the displayed pH value is changed with respect to the calibrated values.
Therefore measurement in a buffer fluid will contain the very offset in the readout.
To set or change the Bias:
Go to the Options menu,
and select Bias.
Toggle the on/off button and select the
bias offset between -9.99 and 9.99 pH.
Confirm and apply with the Set button, or exit
with the Back button to discard any changes.
The Bias setting appears as a notification on the Home screen.
Notification
of a set Bias