Smith R A, Bacon D R
Division of Radiation Science and Acoustics, National Physical Laboratory, Teddington, Middlesex, United Kingdom.
J Acoust Soc Am. 1990 May;87(5):2231-43. doi: 10.1121/1.399191.
A method is described for comparing the sensitivity of two hydrophones over the frequency range 1-15 MHz. This technique forms the basis for the dissemination of national ultrasonic standards in the U.K. over this frequency range. A reference hydrophone is placed in an ultrasonic field and then the device being calibrated is substituted and the two output voltages are compared. This substitution method utilizes a broadband ultrasonic field produced by nonlinear propagation. Thus it is possible to cover the whole frequency range with a single measurement on each hydrophone. The overall uncertainty in the intercomparison of two hydrophones increases from +/- 4.2% at 1 MHz to +/- 8.2% at 15 MHz (95% confidence level). The method has been compared with discrete-frequency substitution, time-delay spectrometry, and absolute calibrations using the National Physical Laboratory (NPL) Primary Standard Laser Interferometer. Various designs and sizes of hydrophones were compared, and agreement was within the combined random uncertainties for all the comparisons.
描述了一种在1-15MHz频率范围内比较两个水听器灵敏度的方法。该技术构成了英国在此频率范围内传播国家超声标准的基础。将一个参考水听器置于超声场中，然后替换待校准的设备，并比较两者的输出电压。这种替代方法利用了非线性传播产生的宽带超声场。因此，对每个水听器进行一次测量就有可能覆盖整个频率范围。两个水听器相互比较时的总体不确定度从1MHz时的±4.2%增加到15MHz时的±8.2%（95%置信水平）。已将该方法与离散频率替代法、时延光谱法以及使用国家物理实验室（NPL）初级标准激光干涉仪的绝对校准法进行了比较。比较了各种设计和尺寸的水听器，所有比较结果的一致性均在组合随机不确定度范围内。
