Cirrus Research CR 151, Руководство пользователя

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optimus sound level meter user manual
Page 41
The microphone should be parallel to the body of the calibrator. Also ensure that the
small bleed-hole next to the microphone cavity is not blocked as this could cause
damage to the microphone.
Your
optimus
sound level meter will automatically make adjustments for the level
produced by the acoustic calibrator and the microphone type fitted to the instrument.
Background Noise
In order for the calibrator to operate as intended, the ambient acoustic noise level
should be no greater than 80dBA.
Stabilisation
In order for the sound pressure level and frequency to stabilise after switching the
calibrator on when coupled to a microphone, a period of at least 3 seconds should be
allowed before performing a calibration.
Changing the Battery
The CR:514 & CR:515 acoustic calibrators use a single 9v alkaline battery. This type of
battery is known as 6F22 or NEDA 1604. It is also commonly known as PP3.