Oil bath for checking sensitivity of ultrasonic instruments - consists of thick plastic vessel containing oil held at constant temp. by heater, agitator and thermometer sensors

摘要

The test appts. for investigating the overall sensitivity and frequency response of ultrasonic measuring instruments, consists of a vessel of thick plastic containing oil held at a constant temp. by a heater, agitator, and thermometer sensors. The ultrasonic transducer is held in a clamp having a universal head and is immersed in the oil. A steel reflector plate held parallel to the surface of the oil, can be adjusted by a feed screw against a double, parallax-free scale. By this means, the reflection path length can be accurately adjusted and the ultrasonic transducer set for optimum sensitivity. An alternative arrangement uses solid blocks of suitable material, having constant, absorption values of different thicknesses.