BS EN 61220:1995
超声波学.场.频率范围0.5MHz-15MHz超声波医疗设备含水听诊器引起的超声场的特性和测量指南
Ultrasonics - Fields - Guidance for the measurement and characterization of ultrasonic fields generated by medical ultrasonic equipment using hydrophones in the frequency range 0.5 MHz to 15 MHz