The optimum dynamic parameters of digital rate meter algorithms

The definition of the “Quality,” Q , of a count-rate meter algorithm is introduced as the reciprocal of the algorithm’s (τ×ε) product, where τ is the response time of the algorithm to a sudden change in the average count rate and where ε is the fractional standard deviation of the steady-state measurement of a constant average count-rate pulse stream. Analytical expressions for τ and ε of digital rate meter algorithms are used to calculate maximum values of Q for both linear and exponential algorithms. The values of the basic algorithm parameters necessary to achieve these minimum (τ×ε) products are derived for both algorithms. The use of these values results in algorithms that have relatively short response times and, simultaneously, relatively small steady-state errors.