計数率計をもつ放射線リレーによる位置制御系の最適設計

Abstract

Optimum design of the position control system using radiation counting rate meter is presented in this paper.As the controlled object (water level or edge of plate) covers the incident window of radiation detector from one side to the other with constant speed, the amount of incident radiation varies. This radiation is measured by a counting rate meter and at the time when the output of rate meter reaches the threshold value, a relay acts and stops the motion of controlled object.In a previous paper, the auther gave some expressions for calculating statistical characteristics of output of rate meter, considering saturation of rate meter.By these expressions mean value and standard deviation of the stopping position of controlled object can be obtained.From these results it is proved that the optimum time constant of the rate meter is the one which stops the controlled object at the position where incident window has just closed, and also that the extent of saturation of rate meter has no effect on standard deviation of stopping position.The necessary total incident counts while the controlled object gose across window can be also obtained, for getting a given standard deviation of stopping position.Compare this control system with a system using radiation scaler (digital measurement), this system is favorable in case of high moving speed of controlled object, because the necessary total incident counts is less than scaler type system.