Characterizing rates of occurrence of various features of a signal is of great importance in numerous types of physical measurements. Such signal features can be defined as certain discrete coincidence events, e.g. crossings of a signal with a given threshold, or occurrence of extrema of a certain amplitude. We describe measuring rates of such events by means of analog multivariate counting analyzers. Given a continuous scalar or multicomponent (vector) input signal, an analog counting analyzer outputs a continuous signal with the instantaneous magnitude equal to the rate of occurrence of certain coincidence events. The analog nature of the proposed analyzers allows us to reformulate many problems of the traditional counting measurements, and cast them in a form which is readily addressed by methods of differential calculus rather than by algebraic or logical means of digital signal processing.
Analog counting analyzers can be easily implemented in discrete or integrated electronic circuits, do not suffer from dead time effects, and allow substantial reduction of pileup effects. Besides extending the scope of counting measurements, analog multivariate counting analyzers allow simple feedback adjustment of the parameters of the acquisition system for optimal performance. In addition, such analyzers can be made simpler, cheaper, lighter, more reliable, more accurate, and less power consuming than digital counting detectors, and thus would be ideally suited for operation in autonomous conditions such as mobile communication, space missions, prosthetic devices, etc. Other obvious immediate applications of the presented analyzers are pulse-height measuring systems used in the acquisition of nuclear radiation spectra.
