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Appendix 2: Calibration Reference & Maximum Levels
The AudioStar Pro is supplied from the factory calibrated for the transducers that
were purchased with it. The exception is the speakers, as those must be calibrated
in the environment where they will be used. The calibration data supplied from
the factory is only valid for GSI supplied transducers and cannot be applied to
non-GSI supplied transducers.
It is recommended that calibration of the instrument and transducers be
performed annually by authorized GSI Representatives using appropriate
calibration instrumentation. If periodic checks are also desired, the tables in this
section provide the SPL values per frequency for each transducer. If the
measured values are not within ± 5 dB at 125, 6,000, 8,000 and 12,000 Hz in the
earphones, the GSI AudioStar Pro should be scheduled for immediate
maintenance.
It is not possible to select a dB HL value outside the limits for a particular
transducer/ frequency combination. An attempt to change or select a hearing
level control that is outside of the limit will cause the dB HL display to flash
momentarily and then the test channel value will be replaced with NR (No
Response). If an audiogram is displayed and the limits for a frequency/transducer
are reached, the symbol for no response is displayed in the audiogram.
It is not possible to select a test frequency that is invalid for a particular
transducer.
The hearing levels listed in the Max HL tables are maximum levels. These levels
are achievable only if ANSI, ISO or GSI reference threshold levels, and not
customized calibration values, are used. At no time will the hearing level limit
exceed 120 dB HL
