4.3.1.2 Proportional counters
A proportional counter operates in the proportional region. The effect of the gas multiplication may increase the number of ions produced by 104. This means that for each electron produced by the original ionization event, there may be ten thousand additional electrons produced. Therefore each ionization event can be distinguished and counted. The output from a proportional counter is a series of pulses which are counted by a counting circuit. In general, the resolving time is generally very short for these counters (less than a microsecond) so high pulse rates can be counted. However, the amplitude of each pulse is very small (of the order of millivolts) and pre-amplification is required before the pulses can be counted.