User Manual

63
8.7.1 Calibration Check
The calibration check is generally used in long term or permanent environmental system. It is
intended to periodically verify that a system is working properly and that the acquisition level is
adequate. To achieve this goal, an actuator has to be installed near the input sensor. Prior the
measurement, the actuator will be exited to provide a reference signal at the input and the obtained
reference spectrum will be saved. During the acquisition, the actuator will be activated periodically.
A comparison of the spectrum during the measurement and the reference spectrum, allows the user
to conclude on the proper operation of the acquisition system.
The generated signal should be loud enough to be way over the normal signal being measured.
Ideally, the generated signal should be a few dB below the maximum range of the input. For
example, the Larson Davis 426A12 actuator typically generates 91 to 97 dB at the input.
The following sections explain how to configure the generator and how to define the reference
spectrum.
8.7.2 Reference Spectrum Interface
Current spectrum on inputs
Averaging
Controls
Generator Setup