[Code of Federal Regulations]
[Title 47, Volume 1, Parts 0 to 19]
[Revised as of October 1, 1999]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR18.305]
[Page 733-734]
TITLE 47--TELECOMMUNICATION
CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION
PART 18--INDUSTRIAL, SCIENTIFIC, AND MEDICAL EQUIPMENT--Table of Contents
Subpart C--Technical Standards
Sec. 18.305 Field strength limits.
(a) ISM equipment operating on a frequency specified in Sec. 18.301
is permitted unlimited radiated energy in the band specified for that
frequency.
(b) The field strength levels of emissions which lie outside the
bands specified in Sec. 18.301, unless otherwise indicated, shall not
exceed the following:
----------------------------------------------------------------------------------------------------------------
RF Power generated by Field strength limit Distance
Equipment Operating frequency equipment (watts) (uV/m) (meters)
----------------------------------------------------------------------------------------------------------------
Any type unless otherwise Any ISM frequency.... Below 500............ 25.................. 300
specified (miscellaneous). 500 or more.......... 25 x SQRT(power/500) \1\300
Any non-ISM frequency Below 500............ 15.................. 300
500 or more.......... 15 x SQRT(power/500) \1\300
Industrial heaters and RF On or below 5,725 MHz Any.................. 10.................. 1,600
stabilized arc welders. Above 5,725 MHz...... Any.................. (\2\)............... (\2\)
Medical diathermy................. Any ISM frequency.... Any.................. 25.................. 300
Any non-ISM frequency Any.................. 15.................. 300
Ultrasonic........................ Below 490 kHz........ Below 500............ 2,400/F(kHz)........ 300
500 or more.......... 2,400/F(kHz) x \3\300
SQRT(power/500).
490 to 1,600 kHz..... Any.................. 24,000/F(kHz)....... 30
Above 1,600 kHz...... Any.................. 15.................. 30
Induction cooking ranges.......... Below 90 kHz......... Any.................. 1,500............... \4\30
On or above 90 kHz... Any.................. 300................. \4\30
----------------------------------------------------------------------------------------------------------------
\1\ Field strength may not exceed 10 <greek-m>V/m at 1600 meters. Consumer equipment operating below 1000 MHz is
not permitted the increase in field strength otherwise permitted here for power over 500 watts.
\2\ Reduced to the greatest extent possible.
\3\ Field strength may not exceed 10 <greek-m>V/m at 1600 meters. Consumer equipment is not permitted the
increase in field strength otherwise permitted here for over 500 watts.
\4\ Induction cooking ranges manufactured prior to February 1, 1980, shall be subject to the field strength
limits for miscellaneous ISM equipment.
(c) The field strength limits for RF lighting devices shall be the
following:
------------------------------------------------------------------------
Field strength limit at 30 meters
Frequency (MHz) (<greek-m>V/m)
------------------------------------------------------------------------
Non-consumer equipment:
30-88........................... 30
88-216.......................... 50
216-1000........................ 70
Consumer equipment:
30-88........................... 10
88-216.......................... 15
216-1000........................ 20
------------------------------------------------------------------------
[[Page 734]]
Notes
1. The tighter limit shall apply at the boundary between two
frequency ranges.
2. Testing for compliance with these limits may be made at closer
distances, provided a sufficient number of measurements are taken to
plot the radiation pattern, to determine the major lobes of radiation,
and to determine the expected field strength level at 30, 300, or 1600
meters. Alternatively, if measurements are made at only one closer fixed
distance, then the permissible field strength limits shall be adjusted
using 1/d as an attenuation factor.
[50 FR 36070, Sept. 5, 1985, as amended at 51 FR 17970, May 16, 1986; 52
FR 43197, Nov. 10, 1987]