Larson Davis SoundExpert LxT, Руководство пользователя

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7-12
Sensitivity Tab LxT Manual
Sensitivity Tab
The Sensitivity tab, shown in FIGURE 7-8, is used
primarily to establish the noise floor of the instrument with
the preamplifier and microphone presently being used and,
from that, determine the under range levels for A, C and Z-
weighting sound level measurements. The overload level is
also determined.
FIGURE 7-8 Sensitivity Tab
Noise Floor
The noise floor is calculated as the energy sum of the
microphone self noise, preamplifier self noise and
instrument self noise.
When using one of the following preamplifiers, identified
automatically when plugged into the LxT,
• Direct
• PRMLxT1
• PRMLxT2B
• PRMLxT1L
• PRMLxT2L
and one of the five most commonly used microphones for
that type of preamplifier, user-selected, a database in the
LxT provides the nominal sensitivity and the self noise of
the preamplifier and microphone pair.
Preamplifier Presently
Connected
Selected Microphone
Peak Overload Level
Under Range Levels
Noise Floor Levels
Self Noise of Selected Microphone,
Unless Value Entered Manually