Welch Allyn AudioScope, Руководство по обслуживанию

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1.7a Operating Program
:
23300 (ASIC TYPE) up to and
including serial no.9609999
Multi-Level AudioScope3
ASIC
The Three Hearing Level AudioScope3 up to and including Serial
Number 960999 uses an ASIC (single application specific integrated
circuit) Microprocessor. This component
is not a service part . If the
ASIC Microprocessor should fail, it will be necessary to replace the
Circuit Board/ASIC assembly with the new
Microcontroller based
circuit board Part No. This is an easy replacement and does not affect
unit operation. Calibrate the Microcontroller based AudioScope3 with
T-13765 AudioScope Calibrator Box explained in Section 2.7.11
Tone Generation:
External resistors and capacitors are used to generate four
different tones at hearing levels of 20, 25, 40 dBs. The output
amplitude is determined by SW2, which selects one resistor for a
hearing level of 20, 25, or 40 dBs respectively.
Operation begins with switching the unit ON . The examination
halogen lamp illuminates immediately. When the start button is
depressed, the AudioScope begins to generate a sequence of
tones starting with PT of 1000 Hz, which is 20 dB higher than the
manually selected specific hearing level. Then the 1000 Hz, 2000
Hz. , 4000 Hz and 500 Hz tones are generated in that order at the
same hearing level. When the cycle is complete, the AudioScopes
returns to the ready state indicated by the Green "Ready" LED.
The whole cycle is completed in less than 20 seconds.