VARIABLE NATURAL VIBRATION FREQUENCY MEASURING RAKE

摘要

PROBLEM TO BE SOLVED: To provide a variable natural frequency measurement rake varying the proper frequency measurement rake. SOLUTION: There are provided a nonmagnetic material hollow beam 11 provided with a sensor 13 measuring pressure or temperature on the outer surface in the axial direction with an interval, a solenoid coil 16 wound on the hollow beam outer surface in the axial direction, a switch 18 switching and supplying current from a power source 17 to the solenoid coil 16, and a moving body 14 provided in the hollow beams and consisting of a magnetic body bound in the direction perpendicular in the axial direction of the hollow beams.