Other faults may be detected with CIC, depending on how severe they are. Changes in diaphragm tension or polarization voltage directly influence the sensitivity and frequency response of the microphone, but such changes have a relatively small influence on microphone cartridge capacitance.
For example, a 2 dB change in the diaphragm tension of a typical sound level meter microphone changes its capacitance (and thus the CIC signal) by approximately 0.5 dB.
CIC is not a replacement for acoustical verification, but CIC can extend the interval between routine acoustical calibrations. Also, CIC is an excellent tool for registering severe faults, but is limited when checking for small sensitivity changes, and even less effective for checking microphone frequency response.
With high-quality, stable microphones, faults are likely to be due to events that significantly change the microphone. A stable CIC response is a reasonable indication that the measurement channel is functioning correctly. Our Calibration Systems provide automated primary and secondary calibration of all measurement microphone, hydrophone, and preamplifiers.