Clarius Scanner HD3 Safety Topics
revision 9 64
is used exceeds the applicable RF compliance level in the table, observe the system to verify
normal operation. If abnormal performance is observed, apply additional measures, such as
reorienting or relocating the system.
The table here provides guidance on conducted and radiated interference from portable and
fixed RF transmitting equipment.
For example, if a portable transmitter has a maximum radiated power of 1 W and an operating
frequency of 156 MHz, it can be operated at distances greater than 1.2 m (3.9 ft) from the
system. Similarly, a 0.01 W Bluetooth wireless LAN smart device operating at 2.4 GHz should
be placed no closer than 0.24 m (9.5 in) from any part of the system.
Avoiding Electromagnetic Interference
An ultrasound system is designed to receive signals at radio frequencies, making them
susceptible to interference generated by RF energy sources. Other examples of interference
are medical equipment, information technology products, and radio and television
transmission towers.
To locate the source, investigate whether the problem resides with the system or the scanning
environment:
• Is the interference intermittent or constant?
• Does the interference show up only with one scanner or with several scanners?
• Do two different scanners operating at the same frequency have the same problem?
• Is the interference present if the system is moved to a different location in the facility?
• Can the EMC coupling path be attenuated? For example, placement of a scanner or printer
close to an ECG cable can increase electromagnetic interference. Moving the cable or
At 80 MHz and 800 MHz, the higher frequency range applies.
The recommended separation distance guidelines in the following table may not
apply to all situations. Electromagnetic propagation is affected by absorption and
reflection from structures, objects, and people.
RECOMMENDED SEPARATION DISTANCES BY TRANSMITTER FREQUENCY
Rated Maximum Output Power
of Transmitter (Watts)
150 kHz to 80 MHz 80 to 800 MHz 800 MHz to 2.5 GHz
0.01 0.35 m (13.8 in) 0.12 m (4.7 in) 0.23 m (9.1 in)
0.1 1.1 m (3.6 ft) 0.38 m (15 in) 0.73 m (28.7 in)
1 3.5 m (11.5 ft) 1.2 m (3.9 ft) 2.3 m (7.5 ft)
10 11 m (36.1 ft) 3.8 m (12.5 ft) 7.3 m (24 ft)
100 35 m (114.8 ft) 12 m (39.4 ft) 23 m (75.5 ft)
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