ISO 16063-32:2016 lays down detailed specification for instruments and procedures of testing the frequency and the phase response of accelerometers by means of shock excitation. It applies to the accelerometers of the piezoelectric, piezoresistive and variable capacitance types with the damping ratio less than critical and in the frequency range up to 150 kHz.
The method presumes that the frequency and the phase responses of the accelerometer under test gained by this method are the best possible characteristics for the mounted accelerometer on the condition that the recommendations for mechanical mounting of accelerometer stated in ISO 5348 are fulfilled and that the mass of the reference shock ball exceeds at least three times the mass of the accelerometer under test.
Phase response of the accelerometer under test gained by this method is considered to be some "virtual" characteristic of accelerometer presuming that there is zero phase shift between the input and output signals at a frequency of 0 Hz.
NOTE 1 It is intended that the user be aware that for the same accelerometer in the field application, the frequency and the phase responses might be different, depending on the mass and compliance of the test structure and the method of mounting. The method allows just a qualitative evaluation of the frequency and the phase response of accelerometers.
NOTE 2 It is intended that the user does not try to get better resolution of the initial parts of the frequency and phase responses of the accelerometer under test than the dynamic range of the adequate characteristic provides it. The best use of the frequency and the phase responses of the accelerometer gained by this method are to get the best fit lines for the initial parts of the mentioned characteristics.