I’m doing a paper on the temperature effects on ultrasonic readings; specifically the temperature effect on the transducer wedge material (Plexiglas, Lucite, Ultem, Rexolite) and how it changes the ultrasonic reading when placed on a steel pipe over a temperature range of 0 deg F to 200 deg F.
The thermal expansion coefficient for plastics does not seem to apply well at the extreme ends this temperature range, the sound velocity of the plastic also changes at the extreme ends, which further changes the expansion when measured ultrasonically. To quantify an ultrasonic thickness change due to temperature change the sound velocity at the various temperatures is required. The temperature/velocity data for plastics is difficult to find. Velocity is related to density and elasticity, > density and < elasticity = faster sound. Does anybody know of published data that references material velocity at various temperatures? Short of that I will be using a micrometer to physically measure material thickness change and reverse engineer to arrive at a material velocity for given temperature. Any ideas/comments welcome.
The thermal expansion coefficient for plastics does not seem to apply well at the extreme ends this temperature range, the sound velocity of the plastic also changes at the extreme ends, which further changes the expansion when measured ultrasonically. To quantify an ultrasonic thickness change due to temperature change the sound velocity at the various temperatures is required. The temperature/velocity data for plastics is difficult to find. Velocity is related to density and elasticity, > density and < elasticity = faster sound. Does anybody know of published data that references material velocity at various temperatures? Short of that I will be using a micrometer to physically measure material thickness change and reverse engineer to arrive at a material velocity for given temperature. Any ideas/comments welcome.
