Welch Allyn REF 29400 User Manual

Page 50

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Welch Allyn OAE Hearing Screener Directions for Use 705353 Rev E

49

b

Over the frequency range 150 kHz to 80 MHz, field strengths should be less than 3 V/m.


Recommended Separation Distances Between Portable and Mobile RF Communications

Equipment and the REF 29400 Series OAE Hearing Screener

The REF 29400 Series OAE Hearing Screener is intended for use in an electromagnetic
environment in which radiated RF disturbances are controlled. The customer or user of the REF
29400 Series OAE Hearing Screener can help prevent electromagnetic interference by
maintaining a minimum distance between portable and mobile RF communications equipment
(transmitters) and the REF 29400 Series OAE Hearing Screener as recommended below,
according to the maximum output power of the communications equipment.

Separation Distance According to Frequency of Transmitter (m)

Rated Max.

Output Power of

Transmitter (W)

150 kHz to 80 MHz d =

(1.17) P

80 MHz to 800 MHz d =

(1.17) P

800 MHz to 2.5 GHz d =

(2.33) P

0.01

0.117

0.117

0.233

0.1

0.37

0.37

0.74

1

1.17

1.17

2.33

10

3.70

3.70

7.37

100

11.70

11.70

23.30

For transmitters rated at a maximum output power not listed above, the recommended separation
distance d in meters (m) can be estimated using the equation applicable to the frequency of the
transmitter, where P is the maximum output power rating of the transmitter in watts (W) according
to the transmitter manufacturer.

Note 1: At 80 MHz and 800 MHz, the separation distance for the higher frequency range applies.

Note 2: These guidelines may not apply in all situations. Electromagnetic propagation is affected
by absorption and reflection from structures, objects, and people.













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