Welch Allyn AM 232, Руководство по эксплуатации

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31 12-16-08
Typical testing session
Pretest Review
1. Turn the instrument on.
2. Check that the earphones are operating properly.
3. Seat subject comfortably in the test area.
4. Explain the test procedure.
5. Assist subject with the earphones.
6. Select the desired tone type.
7. Make appropriate entry on the subject’s audiogram.
Familiarization
1. Set the Routing selector to route the test tone to the selected ear.
2. Demonstrate the 1000 Hz tone at a 40 dB level. The Tone Duration should be
between 1 and 2 seconds.
3 Set the HL control to -10 dB .
4. Practice: Beginning with the tone on continuously (Present Bar held down),
gradually increase the intensity by turning the HL control until a response
occurs. Switch the tone off for at least two seconds and present the tone again at
the same level. If there is a second positive response, proceed to threshold
measurement. If a second response does not occur, repeat this step. Practice is
preliminary to threshold measurement determination and is to be completed at
each new frequency setting.