Abstract
The dynamic response of ISE has been measured with respect to the perturbations of two external electric fields, weak and strong: the first was the field of the environmental electromagnetic waves in space and the second was a static electric pulse field applied to the surface of the ISE. The ISE′s can be classified into two types by the responses to the weak perturbation: in one the surface is capacity-dominant and in the other it is conductivity-dominant. The Ag+, Cu2+ and Pb2+ ISE′s belong to the former and those of F-, Cl-, Br- and I- to the latter. The response of the former type ISE′s to the strong perturbation has two different relaxation times, τ′s: one (X) is around a few μs or shorter and the other (Y) is in a range around 20 or 5μs for Cu2+ and Pb2+, respectively. The results of the weak and the strong perturbation coincide in the classification of the ISE′s. The ISE′s which are classified as the conductive ones miss X and Y, except F- electrode which shows τ of 80μs. No frequency dependence of τ can be measured for X, but Y values for Cu2+ and Pb2+ have a requency dependence with the optimum at around 800Hz.
