Brüel & Kjær 8103 miniature hydrophone
A small, high-sensitivity transducer for making absolute sound measurements over the frequency range 0.1Hz to 180 kHz with a receiving sensitivity of −211 dB re 1V/μPa. It has a high sensitivity relative to its size and good all-round characteristics, which make it generally applicable to laboratory, industrial and educational use. Type 8103's high frequency response is especially valuable when making acoustic investigations of marine animals and in the measurement of the pressure-distribution patterns in ultrasonic-cleaning baths. It is also useful for cavitation measurements.