compound ultrasonic transducer

The use of ultrasonic distance measuring transducer is to study the state of stress in the solids that is a very significant method of ultrasonic testing. This is due to the fact that the stress in the solids that is related to its longitudinal and transverse wave velocity. Ultrasound transducers are an extremely important part of this measurement. Accuracy of the result plays an important role. For the purpose of stress measurement, we developed a composite ultrasonic probe that is consisting of two longitudinal waves of different frequency and two transverse waves with perpendicular polarization directions. 

As long as the ultrasonic distance sensor is used to measure the sound wave velocity at a certain point on a solid surface and the sound velocity of two transverse waves are perpendicular to each other on the point, the two principal stresses at that point and its direction can be calculated. Different long range distance measurement sensors were used in the previous measurements. When is measuring the speed of sound wave of the longitudinal wave and the perpendicularity of the two polarization directions, it is necessary to change and move the probe several times. 

Because each time the ultrasonic distance transducer sensor cannot be fixed completely at the same point, the measurement error is generated, and because each time the fixed time It is impossible to completely match the layers, which will also bring errors to the measurement. About this 2 Mhz ultrasonic sensor, only one measurement is required for each measurement together, we can take advantage of two mutually perpendicular polarization directions transverse to the wafer is determined in the principal stress direction of the solid, and the solid can be measured simultaneously in the two vertical shear.