Welch Allyn Acuity Directions For Use Manual page 191

Directions for use
Recommended Separation Distances Between Portable and Mobile RF Communications Equipment and the
Acuity System
The Acuity System is intended for use in an electromagnetic environment in which radiated RF disturbances are
controlled. The customer or the user of the Acuity System can help prevent electromagnetic interference by maintaining
a minimum distance between portable and mobile RF communications equipment (transmitters) and the Acuity System
as recommended below, according to the maximum output power of the communications equipment.
Rated Maximum Output
Power of Transmitter
W
0.01
0.1
1
10
100
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 might not apply in all situations. Electromagnetic propagation is affected by absorption and
Separation Distance According to Frequency of Transmitter
m
150 kHz to 80 MHz
d = 1.2
0.12
0.38
1.2
3.8
12
reflection from structures, objects and people.
80 MHz to 800 MHz
d = 1.2
P P
0.12
0.38
1.2
3.8
12
Chapter 11 Specifications 187
800 MHz to 2.5 GHz
d = 2.3
P
0.23
0.73
2.3
7.3
23