Any type unless otherwise specified (miscellaneous)
Any ISM frequency
Below 500
500 or more
25
25 × SQRT(power/500)
300
1300
Any non-ISM frequency
Below 500
500 or more
15
15 × SQRT(power/500)
300
1300
Industrial heaters and RF stabilized arc welders
On or below 5,725 MHz
Above 5,725 MHz
Any
Any
10
(2)
1,600
(2)
Medical diathermy
Any ISM frequency
Any non-ISM frequency
Any
Any
25
15
300
300
Ultrasonic
Below 490 kHz
Below 500
500 or more
2,400/F(kHz)
2,400/F(kHz) × SQRT(power/500)
300
3300
490 to 1,600 kHz
Above 1,600 kHz
Any
Any
24,000/F(kHz)
15
30
30
Induction cooking ranges
Below 90 kHz
On or above 90 kHz
Any
Any
1,500
300
430
430
1, Field strength may not exceed 10 μV/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 μV/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.
我们以超声波产品,超声波主频为1.6MHz以上,辐射限值为例,对比FCC PART 15B CLASS B级民用辐射限值,进行对比:
FCC Part 18给出超声波产品,超声波主频为1.6MHz以上辐射限值,FCC给出的是30m处的辐射限值为15uV/m,然后转换为对数为 23.521825181113627dBuV/m,然后将30m限值转为10m限值为 23.521825181113627+20log(30/10)=33.06dBuV/m,如果是转换为3m限值,则为,43.52dBuV/m
FCC Part 15辐射限值如下:
FCC Class B 辐射限值
所以,综上所述,以家用雾化器为例子,如果用FCC Part 18工科医辐射限值与FCC Part 15B CLASS B辐射限值对比,可以得知如下表格数据,所以说,如果超声波是大于1.6MHz的主频对比15B与18的限值,低频30MHz~88MHz的限值FCC Part 15B严3.52dB,216MHz~960MHz频率FCC Part 15B又松2.5dB、960MHz以上的话FCC Part 15B又松10.4594dB,详细如下: