CASELLA CEL CEL-62 Series, Руководство оператора

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Casella CEL 22
5. LOW AND HIGH SOUND LEVELS
Low Level Sounds .
Providing the sound level being measured is within the linearity range (refer to Appendix
B paragraph “e - Linear operating range”), self generated noise and linearity corrections
can be ignored.
When the measured RMS sound level is below the linearity range and 3 dB above the
self generated noise (refer to Appendix B paragraph “h - Self generated noise), it is
possible to correct the measured level by the following formula:
Note: As the CEL62X is a single range instrument capable of reading to zero dB, and
the only non linearity error will be due to self generated noise, then there is no under-
range indicator.
L
act
= 10log(10
(L
ms
)/10
– 10
(L
sg
)/10
)
Where L
act
= Actual corrected sound level
L
ms
= Measured sound level
L
sg
= Self generated noise level
High Level Sound (Overload).
When a sound level is detected that is above the linear operating range, the display will
indicate overload by a red upward facing arrow at the top of the display.
If the CEL-62X is not completing a measurement run then the overload indication will
automatically reset approximately 2 seconds after the sound level is reduced to below
overload.
If the CEL-62X is completing a measurement run then the overload indication will
remain, even if the overload sound level is reduced, until the measurement run is
terminated manually or by the timer. If the data collected during the run is viewed on the
CEL-62X, or downloaded to a PC, then an overload will be reported in the data.
Refer to sections F,H & J to set run durations, memory results and run screens.