Patent ID: 6321590
Filing Date: 2001-11-27
Classification: G01M

Abstract:
A leakage measuring device constructed such that a cylinder has an inside thereof divided into one pressure chamber and an other pressure chamber by a piston rod mounted in said cylinder, said one pressure chamber is connected with a pressurizer and said other pressure chamber is connected with a circuit which constitutes a measuring object, and based on the movement of said piston when said one pressure chamber is pressurized, a leakage of said circuit which constitutes said measuring object is measured,the improvement being characterized in that pressure receiving areas of said piston in said one pressure chamber and said other pressure chamber are made equal to each other, and a detection rod which is fixedly secured to said cylinder side is inserted into a detection hole formed along an axis of said piston while holding said detection rod in a non-contact condition, said detection rod and said detection hole constitute a non-contact stroke sensor; andwherein a lap portion is formed in the vicinity of the center of the inside of said cylinder and said piston is slidably inserted into a hole formed in said lap portion.