Preferred Label : isopotential point;
IUPAC definition : For an ion-selective electrode cell, there is often a particular activity of the measured
ion for which the emf of the cell is independent of temperature. That activity, and
the corresponding potential difference, defines the isopotential point. The specification
of the ion-selective electrode and outer reference electrode must be described. Comment:
When an isothermal cell is used with identical reference electrodes, the isopotential
point is the activity of sensed species that gives zero net membrane potential, e.g.
sensed activity is the same in the inner and outer (test) solution. Calibration lines
for different cell temperatures have different slopes, but intersect at a common activity
point. Cells with temperature gradients are not recommended.;
Origin ID : I03304;
See also
For an ion-selective electrode cell, there is often a particular activity of the measured
ion for which the emf of the cell is independent of temperature. That activity, and
the corresponding potential difference, defines the isopotential point. The specification
of the ion-selective electrode and outer reference electrode must be described. Comment:
When an isothermal cell is used with identical reference electrodes, the isopotential
point is the activity of sensed species that gives zero net membrane potential, e.g.
sensed activity is the same in the inner and outer (test) solution. Calibration lines
for different cell temperatures have different slopes, but intersect at a common activity
point. Cells with temperature gradients are not recommended.
