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Step 3: Performing a Frequency Response Calibration
1. Mount the microphone onto the preamplifier in the AL0010 Frequency Calibration
Stand
2. Carefully unscrew the microphone protection grid.
3. Place the electrostatic actuator onto the microphone diaphragm
4. In the software main menu, click
FreqCalibration
and a new window opens. This
window has a menu bar with the following features: Measurement, Test limits,
Setup, and Debug. For measurement, it’s only necessary to use the Measurement
mode. The rest is only for debugging and information about the setup.
5. Then
click
Start Measurement
The calibration system displays three curves and the upper and lower test limits for
the specific microphone type:
The white curve indicates the most
recently measured level
The blue curve indicates the previously
measured level.
The yellow curve indicates the free field
corrections
The red lines indicate the upper and
lower limits for the specific microphone
6. Run the test a couple of times to ensure the microphone capsule is vented. When
the white and the blue curves have stabilized, click
Accept
.
Note:
If the “Overload” LED is red, the measurement is probably not valid.