Larson Davis SoundTrack LxT, Руководство пользователя

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7-4
Acoustic Calibration LxT Manual
History Tab
To create a history record for a
calibration, it must be saved;
calibrations must also be saved to
export post-calibration data to
software. The History tab lists the results, along with the date and
time, of the ten most recent calibrations performed using the
same type of preamplifier as presently connected to the LxT.
The preamplifier name appears at the top of the tab
(PRMLxT1 in this example). The preamplifier type is read
automatically when the instrument is booted up, or
following a change in preamplifier. The value of sensitivity
in dB re. 1 V/Pa and the variation of the sensitivity
determined from that calibration relative to the calibration
prior to that,

dB, are presented for each calibration.
Sensitivity Tab
When performing an acoustic calibration, the Sensitivity tab
is used to select the microphone being used.
Certification Tab
The Certification tab shows the date of the last certification,
the due date for the next certification, and information about
the calibration facility. You can also enter your certification
interval and certification reminder from this tab.
Exiting from the Calibration Function
Press the Close Softkey to exit from any of the calibration
tabs to the Control Panel.
Acoustic Calibration
This is the most commonly used calibration method, and the
one required by most national and international standards
prior to performing a measurement. A sound level calibrator
is used to apply an acoustical signal of a known amplitude
and frequency to the microphone. From the voltage level
measured by the meter, the sensitivity can be determined.
With this technique, it is assumed that the calibrator is
functioning correctly; any variation in level results in an
improper calibration and an erroneous value of sensitivity.
For this reason, the user is advised to compare the newly
determined sensitivity with the previous sensitivity to ensure
that significant variations have not occurred.