Calibration is an essential step in every precision measurement. It establishes the relationship between the sound pressure and the electrical output of the microphone.
Calibration can be performed at either 250 Hz or at 1 kHz. Both frequencies have their advantages and disadvantages.
250 Hz is in the frequency range where the frequency response of almost all microphones is flat and will therefore give the most accurate calibration.
If, however, the microphone is used in connection with measuring equipment with weighting filters, for example a sound level meter with A-weighting, the 250 Hz signal will be attenuated by the weighting network. In this case it might be advantageous to use a 1 kHz calibration frequency.
At 1 kHz, the weighting filters have 0 dB attenuation and will therefore not affect the calibration.
On the other hand, since the frequency response of the microphone is not flat, a small error could be introduced.
GRAS 90CA-S2 Microphone Calibration System, PXI
The GRAS 90CA-S2 Microphone Calibration System provides for automated and reliable level and frequency response calibration of measurement microphones. The implemented calibration methods conform with relevant standards as listed in the specifications...
GRAS OP0024 Kit for Frequency Calibration of Flush-mount Microphone Sets
The GRAS OP0024 kit contains a calibration holder, electrostatic actuator and actuator calibration adapters for 1/8" and 1/4" size of GRAS Flush-mount Microphone Sets. For 1/2" size no adapter is used...
GRAS OP0026 Kit for Frequency Calibration of 1/4" Surface Microphones
The GRAS OP0026 kit contains an electrostatic actuator and an actuator calibration holder for GRAS precision 1/4" surface microphones...
GRAS RA0014 1/2'' Electrostatic Actuator
The GRAS RA0014 1/2'' Electrostatic Actuator is an electrostatic actuator for testing the frequency response of standard 1/2”, 1/4” and 1/8" microphones; adapters are included for testing 1/4” and 1/8"microphones. The GRAS RA0014 can be connected directly to the GRAS 14AA Actuato..
GRAS RA0014-S1 1/2'' Electrostatic Actuator for 40AU-1
The GRAS RA0014-S1 1/2'' Electrostatic Actuator is for testing the frequency response of the microphone 40AU-1. The GRAS RA0014-S1 can be connected directly to the GRAS 14AA Actuator Supply ...
GRAS RA0015 1'' Electrostatic Actuator
The GRAS RA0015 is an electrostatic actuator for testing the frequency response of standard 1” microphones. The RA0015 can be connected directly to the GRAS 14AA Actuator Supply...