Analysis on calculated reactivity error caused by inaccuracy of sampling intervals

Recently personal computers are widely used in various instrumentation systems. However some operating system does not have enough accuracy for controlling timer. When there are deviations between the absolute time of the natural phenomena and the time controlled by the operating system, error might be introduced. In a digital reactivity meter, inverse kinetic equations are solved for reactivity. When the sampling interval deviates from the intended interval, the calculated reactivity includes some errors. From this point of view we evaluated errors introduced in the reactivity calculation by a digital reactivity meter. It is found that the error characteristics are different with the added reactivity shape such as constant, sinusoidal, saw tooth shape of ramp. In this paper the results of quantitative error evaluations and some counter measures are discussed.