The HD 9101 sound level generator is a battery-fed portable sound source, suitable for calibrating sound level metres (portable and laboratory versions) and acoustic measuring stations. The advantages of the HD 9101 calibrator are the following:
- With the frequency of sound pressure at 1000 Hz, calibration may be carried out without correction factors, irrespective of weightings A, B, C and D.
- The sound pressure generated is independent of atmospheric pressure, so it is not necessary to correct the value to suit the atmospheric pressure (contrary to pistonphones which require correction).
- Large calibration equivalent volume: the volume between the microphone and the generator and the equivalent volume of the microphone do not have an appreciable influence on the measurement
(the coupling between the microphone and the calibrator may be loose).
- The HD 9101 calibrator may be used conveniently in the laboratory and in the field.
- It is simple to use, so it may be used even by non-skilled operators.