natus Madsen A450, Руководство пользователя

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Selectable transducers
AC: TDH 39 headphones, and Insert Earphones
BC: Bone conductor (Mastoid)
SF: • Passive sound field speaker using the built-in amplifier, or
• External amplifier using the line output.
Transducer options depend on how Madsen A450 is ordered and calibrated.
1. All headbands supplied with transducers comply with the ISO 389 series for that model of transducer unless oth-
erwise specified.
2. Headphone TDH-39 can be supplied with two different headbands, HB7 and HB8:
- For adult skulls or above normal skull size, HB8 shall be applied (HB8 is in compliance with ISO 389).
- For children and below normal skull size HB7 shall be applied (HB7 provides a greater force required to accommodate
smaller skull size)
For audiometric testing outside of noise attenuating test rooms, Natus recommends using earphones which feature passive
noise reduction. For the applicable earphone models, the attenuation is specified in the following table.
Sound attenuation values for earphones and headphones
Frequency Attenuation
(Hz)
TDH39 with
MX41/AR cushion
(dB)
Insert earphones
(dB)
63 N/A N/A
125 3 33
160 4 34
200 5 35
250 5 36
315 5 37
400 6 37
500 7 38
630 9 37
750 N/A N/A
800 11 37
1000 15 37
1250 18 35
1500 N/A N/A
Madsen A450 27
16 Technical specifications