Larson Davis 831, User Manual

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8-18 E.A. Check Model 831 Manual
E.A. Check
When using a Larson Davis Model 426A12 Outdoor
Preamplifier and Power Supply or Model 2100 Outdoor
Preamplifier, this menu is used to perform a remote
calibration check by switching on the electrostatic actuator
(E.A.) contained within rain hat of the Model 426A12.
FIGURE 8-18 E.A. Check Menu
Initial Calibration
The sound pressure level produced by the E.A., typically in
the range 94 to 96 dB, will depend upon the manner in
which the rain hat is mounted upon the microphone, so it
may change whenever removed and then replaced. However,
once in place, it does generate a precision level that can be
used to determine changes in the system calibration, whether
in the microphone, instrumentation, cabling or in the
Electrostatic Actuator itself. As a result, after installation of
the rain hat, an initial calibration must be performed to
establish the standard E.A. level. To do this, highlight
E.A