There are two ways of quantitative analysis is EPMA to obtain an average counting rate; counting for a fixed time and counting pulses for a fixed charge.
The method of counting pulses for a fixed charge which is the more general one, is not suitable for quantitative measurements on specimens having a heterogeneous structure be-cause the specimen current varies in different regions of the structure.
This paper initially presents an adaptor con-verting the device for counting pulses for a fixed charge into that of counting for a fixed time, and then shows by some experiments that the adaptor is also useful for quantitative analysis in EPMA.