设备类型
For any ultrasonic gauging application, the choice of an optimum gauge and transducer will be based on the type of test material, its thickness range, and the degree of measurement accuracy required. It is also necessary to consider part geometry, temperature, and any other special circumstances that may affect the test setup. Transducer selection is discussed in detail in Section 2 of this tutorial.
Commercial ultrasonic thickness gauges are divided into two types, corrosion gauges and precision gauges. Perhaps the single most important application for ultrasonic gauging is measuring the remaining wall thickness of metal pipes, tanks, structural parts, or pressure vessels that are subject to internal corrosion that cannot be detected from the outside. Corrosion gauges are optimized for this type of measurement, and they use specialized dual-element transducers with separate transmitter and receiver elements angled toward each other to create a v-shaped sound path in the test material. Precision gauges are generally used for all types of measurement other than corrosion survey, involving a wide variety of engineering materials and geometries. They use single-element transducers.
Within those two general categories, instruments range from simple to sophisticated. The simplest gauges are small, handheld devices that are optimized for specific applications using a limited number of transducers. More sophisticated instruments incorporate waveform displays to aid the operator in test setup and interpretation, as well as more advanced signal analysis software. Data logging capability and PC compatibility are universal among the better instruments currently available on the market.
