Research On Absolute Calibration Of Vector Hydrophones With Very Low Frequency

Recently, vector hydrophones, with the lower and lower working frequency, arebecoming smaller and smaller. The standing-wave tube can be used to effectively calibratethe acoustics pressure sensitivity of very low frequency hydrophones in laboratory. Based onthe theory of column wave-guide, this paper will give an analysis and run simulations aboutthe rationale of absolutely calibrating hydrophones in the standing-wave tube. Testingexperiments are also made on this whole standing-wave tube calibration equipment.Through formula derivation, this paper gives the calibration formula for the acousticspressure sensitivity of vector hydrophones in the standing-wave field. The distribution ofsound pressure in the standing-wave tube is also described. ANSYS software can be used tosimulate the sound field in the stainless steel standing-wave tube with a round thin boardvibrating as a piston. The numerical values of sound pressure, picked up by mathematicformula and simulation, are contrasted and compared, and then this paper fixes up thefrequency range for absolute calibration of hydrophones.This paper collects a great deal of test data about sound pressure and vibration velocityof water point in this standing-wave tube. Experiments are carried out to absolutely calibratevector hydrophones. All the results are showing that: the standing-wave tube calibrationsystem is not only fit for comparison calibration but also absolute calibration.