47 C.F.R. Subpart C—Technical Standards
Title 47 - Telecommunication
Title 47: Telecommunication
PART 18—INDUSTRIAL, SCIENTIFIC, AND MEDICAL EQUIPMENT
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Subpart C—Technical Standards
§ 18.301 Operating frequencies.
ISM equipment may be operated on any frequency above 9 kHz except as indicated in §18.303. The following frequency bands, in accordance with §2.106 of the rules, are allocated for use by ISM equipment:
------------------------------------------------------------------------ ISM frequency Tolerance------------------------------------------------------------------------6.78 MHz.................................. ±15.0 kHz13.56 MHz................................. ±7.0 kHz27.12 MHz................................. ±163.0 kHz40.68 MHz................................. ±20.0 kHz915 MHz................................... ±13.0 MHz2,450 MHz................................. ±50.0 MHz5,800 MHz................................. ±75.0 MHz24,125 MHz................................ ±125.0 MHz61.25 GHz................................. ±250.0 MHz122.50 GHz................................ ±500.0 MHz245.00 GHz................................ ±1.0 GHz------------------------------------------------------------------------
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Note: The use of the 6.78 MHz ±15 kHz frequency band is subject to the conditions of footnote 524 of the Table of Allocations. See §2.106.
§ 18.303 Prohibited frequency bands.
Operation of ISM equipment within the following safety, search and rescue frequency bands is prohibited: 490–510 kHz, 2170–2194 kHz, 8354–8374 kHz, 121.4–121.6 MHz, 156.7–156.9 MHz, and 242.8–243.2 MHz. § 18.305 Field strength limits.
(a) ISM equipment operating on a frequency specified in §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 §18.301, unless otherwise indicated, shall not exceed the following:
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---------------------------------------------------------------------------------------------------------------- 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.......... 25xSQRT(power/500).. \1\300 Any non-ISM frequency Below 500............ 15.................. 300 500 or more.......... 15xSQRT(power/500).. \1\300Industrial 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.................. 300Ultrasonic........................ 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.................. 30Induction 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 mV/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 mV/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.
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(c) The field strength limits for RF lighting devices shall be the following:
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------------------------------------------------------------------------ Field strength limit at 30 meters Frequency (MHz) (mV/m)------------------------------------------------------------------------Non-consumer equipment: 30-88........................... 30 88-216.......................... 50 216-1000........................ 70Consumer equipment: 30-88........................... 10 88-216.......................... 15 216-1000........................ 20------------------------------------------------------------------------
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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] § 18.307 Conduction limits.
For the following equipment, when designed to be connected to the public utility (AC) power line the radio frequency voltage that is conducted back onto the AC power line on any frequency or frequencies shall not exceed the limits in the following tables. Compliance with the provisions of this paragraph shall be based on the measurement of the radio frequency voltage between each power line and ground at the power terminal using a 50 μH/50 ohms line impedance stabilization network (LISN).
(a) All Induction cooking ranges and ultrasonic equipment:
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------------------------------------------------------------------------ Conducted limit (dBmV) Frequency of emission (MHz) ---------------------------------------- Quasi-peak Average------------------------------------------------------------------------0.009-0.05..................... 110................ _0.05-0.15...................... 90-80 *............ _0.15-0.5....................... 66 to 56 *......... 56 to 46 *0.5-5.......................... 56................. 465-30........................... 60................. 50------------------------------------------------------------------------* Decreases with the logarithm of the frequency.
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(b) All other part 18 consumer devices:
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------------------------------------------------------------------------ Conducted limit (dBmV) Frequency of emission (MHz) ---------------------------------------- Quasi-peak Average------------------------------------------------------------------------0.15-0.5....................... 66 to 56 *......... 56 to 46 *0.5-5.......................... 56................. 465-30........................... 60................. 50------------------------------------------------------------------------* Decreases with the logarithm of the frequency.
------------------------------------------------------------------------ Maximum RF line voltage measured Frequency (MHz) with a 50 uH/50 ohm LISN (uV)------------------------------------------------------------------------Non-consumer equipment: 0.45 to 1.6........................................ 1,000 1.6 to 30.......................................... 3,000Consumer equipment: 0.45 to 2.51....................................... 250 2.51 to 3.0........................................ 3,000 3.0 to 30.......................................... 250------------------------------------------------------------------------
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(d) If testing with a quasi-peak detector demonstrates that the equipment complies with the average limits specified in the appropriate table in this section, additional testing to demonstrate compliance using an average detector is not required.
(e) These conduction limits shall apply only outside of the frequency bands specified in §18.301.
(f) For ultrasonic equipment, compliance with the conducted limits shall preclude the need to show compliance with the field strength limits below 30 MHz unless requested by the Commission.
(g) The tighter limits shall apply at the boundary between two frequency ranges.
[50 FR 36067, Sept. 5, 1985, as amended at 52 FR 43198, Nov. 10, 1987; 64 FR 37419, July 12, 1999; 67 FR 45671, July 10, 2002] § 18.309 Frequency range of measurements.
(a) For field strength measurements:
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---------------------------------------------------------------------------------------------------------------- Range of frequency measurementsFrequency band in which device operates ------------------------------------------------------------------------ (MHz) Lowest frequency Highest frequency----------------------------------------------------------------------------------------------------------------Below 1.705............................ Lowest frequency generated in the 30 MHz. device, but not lower than 9 kHz.1.705 to 30............................ Lowest frequency generated in the 400 MHz. device, but not lower than 9 kHz.30 to 500.............................. Lowest frequency generated in the Tenth harmonic or 1,000 MHz, device or 25 MHz, whichever is whichever is higher. lower.500 to 1,000........................... Lowest frequency generated in the Tenth harmonic. device or 100 MHz, whichever is lower.Above 1,000............................ ......do........................... Tenth harmonic or highest detectable emission.----------------------------------------------------------------------------------------------------------------
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(b) For conducted powerline measurements, the frequency range over which the limits are specified will be scanned.
[50 FR 36070, Sept. 5, 1985, as amended at 51 FR 17971, May 16 1986] § 18.311 Methods of measurements.
The measurement techniques which will be used by the FCC to determine compliance with the technical requirements of this part are set out in FCC Measurement Procedure MP–5, “Methods of Measurements of Radio Noise Emissions from ISM equipment”. Although the procedures in MP–5 are not mandated, manufacturers are encouraged to follow the same techniques which will be used by the FCC.
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