根据对未经平整的粗糙锈蚀表面分别进行超声波厚度测量和机械测量的比较试验，发现超声波测量的平均误差为0.6~2.2 mm。为解决该问题，建议使用一种表面回波持续时间的误差修正法，并选用合适的2.25 MHz宽带换能器进行测量。该方法也适用于喷漆的表面检查。

Experiments comparing the measured value of ultrasonic thickness measurements and mechanical measurements on rough corroded materials without flattening the test surface were carried out. An average measurement error of from 0.6 mm to 2.2 mm was found in the ultrasonic measurements. To address the problem, an error correction method using surface echo duration was proposed. A 2.25 MHz broadband type transducer was suitable for the measurement and the proposed method can also be applied to a painted test surface.