Conversion of a multichannel analyser into an analogue signal averager.

An analogue to digital (AD) converter is described which may be used to transform a multichannel analyser into an analogue signal averager suitable for analysis of analogue signals in the frequency range from DC to typically 40 kHz and signal amplitudes in the millivolt to volt range. The AD converter operates on a triggered basis and is capable of sampling an analogue signal at a maximum rate of 100 kHz while maintaining a conversion linearity of better than 1 % and voltage resolution equal to 2.5 % of the maximum permissible input signal level. Considerably better voltage resolution is obtained by averaging over several repetitions of the input signal and also at smaller sampling rates where more time is available for digitizing the analogue signal between successive samples. Operation of the signal averaging system has been extended to the range of tens of gigahertz by averaging suitably the samples recorded by a sampling oscilloscope.