Larson Davis System 824, Reference Manual

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9/12/00 System 824 Virtual Instruments 5-9
Sound Exposure
The System 824 lets you set the criteria level and criterion
time for Dosimetry measurements. A 100% dose occurs if a
person is exposed to a constant sound field with a SPL equal
to the criterion level, for the criterion time or full dose hours.
The criterion level setting can take on any integer value
within the following range:
0 to 255 dB
Exposures at higher sound exposure levels than the overall
criterion level will result in a 100% dose in less time; or, if
exposure continues, the overall dose will exceed 100%.
The following are examples of the System 824 Sound Expo-
sure displays:
LOG and ISM Measuring Ranges
The following table presents the typical RMS detectors mea-
suring ranges for the LOG and ISM instruments:
NOTE: Ranges are in dB SPL using a
typical 2541 microphone with 44.1 mV/
Pa sensitivity. See Appendix C for more
824 specifications.
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#
$%
20–108 dB 25–108 dB 25–108 dB
&
23–128 dB 28–128 dB 30–128 dB
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43–148 dB 48–148 dB 50–148 dB