1997 Volume 46 Issue 1 Pages 1-10
A void fraction measuring system has been developed, which is composed of a small californium-252 neutron source, a moderating type neutron detector and a data acquisition system. The system is used for on-line measurement of void fraction in an oil tube. To reduce the background count in neutron measurement, optimum condition were examined for the thickness of moderator around a BF3 counter and shields surrounding a void measuring portion. Calibration of the void fraction measurement was carried out by using powder simulation material in a stationary state. The effectiveness of the system was verified by means of the comparison between the present method and the oil sampling one. Finally the system was applied to the automatic transmission (AT) placed on a chassis dynamometer test bench and the performance of the defoamant of AT fluid was successfully evaluated.
