Emission limits
The published limits this tool reads results against. Every number below comes from the same file the analyzer uses, so there is no version of this page that can disagree with a result.
Radiated
FCC Part 15 Class B, radiated
47 CFR 15.109(a) · quasi-peak detector · measured at 3 m
| Frequency | Limit (dBuV/m) | As published |
|---|---|---|
| 30 MHz – 88 MHz | 40 | 100 µV/m |
| 88 MHz – 216 MHz | 43.5 | 150 µV/m |
| 216 MHz – 960 MHz | 46 | 200 µV/m |
| 960 MHz – 40 GHz | 54 | 500 µV/m |
Verified against law.cornell.edu/cfr/text/47/15.109, read 11 Sep 2026 (as amended 80 FR 33447, 12 Jun 2015).
FCC Part 15 Class A, radiated
47 CFR 15.109(b) · quasi-peak detector · measured at 10 m
| Frequency | Limit (dBuV/m) | As published |
|---|---|---|
| 30 MHz – 88 MHz | 39.1 | 90 µV/m |
| 88 MHz – 216 MHz | 43.5 | 150 µV/m |
| 216 MHz – 960 MHz | 46.4 | 210 µV/m |
| 960 MHz – 40 GHz | 49.5 | 300 µV/m |
Verified against law.cornell.edu/cfr/text/47/15.109, read 11 Sep 2026.
Conducted, at the mains port
FCC Part 15 Class B, conducted, quasi-peak
47 CFR 15.107(a) · quasi-peak detector
| Frequency | Limit (dBuV) |
|---|---|
| 150 kHz – 500 kHz | 66 → 56 |
| 500 kHz – 5 MHz | 56 |
| 5 MHz – 30 MHz | 60 |
A segment written 66 → 56 falls linearly with the logarithm of frequency. At the geometric mean of its endpoints the limit is therefore the arithmetic mean of the two levels — 61 dBµV at 0.274 MHz, not at 0.325.
Verified against law.cornell.edu/cfr/text/47/15.107, read 11 Sep 2026.
FCC Part 15 Class B, conducted, average
47 CFR 15.107(a) · average detector
| Frequency | Limit (dBuV) |
|---|---|
| 150 kHz – 500 kHz | 56 → 46 |
| 500 kHz – 5 MHz | 46 |
| 5 MHz – 30 MHz | 50 |
A segment written 66 → 56 falls linearly with the logarithm of frequency. At the geometric mean of its endpoints the limit is therefore the arithmetic mean of the two levels — 61 dBµV at 0.274 MHz, not at 0.325.
Verified against law.cornell.edu/cfr/text/47/15.107, read 11 Sep 2026.
FCC Part 15 Class A, conducted, quasi-peak
47 CFR 15.107(b) · quasi-peak detector
| Frequency | Limit (dBuV) |
|---|---|
| 150 kHz – 500 kHz | 79 |
| 500 kHz – 30 MHz | 73 |
Verified against law.cornell.edu/cfr/text/47/15.107, read 11 Sep 2026.
FCC Part 15 Class A, conducted, average
47 CFR 15.107(b) · average detector
| Frequency | Limit (dBuV) |
|---|---|
| 150 kHz – 500 kHz | 66 |
| 500 kHz – 30 MHz | 60 |
Verified against law.cornell.edu/cfr/text/47/15.107, read 11 Sep 2026.
At a band edge, the tighter limit applies
A frequency that falls exactly on the boundary between two segments belongs to both, and the stricter of the two governs. At 88 MHz exactly, FCC Class B is 40 dBµV/m (100 µV/m) and not 43.5. A clock harmonic landing on a band edge is a common way to be surprised by a test report.
How far up the scan has to go
| Highest frequency generated or used | Measure up to |
|---|---|
| below 1.705 MHz | 30 MHz |
| below 108 MHz | 1 GHz |
| below 500 MHz | 2 GHz |
| below 1 GHz | 5 GHz |
| 1 GHz and above | the 5th harmonic, or 40 GHz, whichever is lower |
Verified against law.cornell.edu/cfr/text/47/15.33, read 11 Sep 2026.
Reading the units
Radiated limits are field strengths in µV/m, quoted here in dBµV/m as 20·log₁₀(µV/m). 100 µV/m is 40 dBµV/m. Conducted limits are voltages at the mains port in dBµV, measured across a 50 µH / 50 Ω line impedance stabilisation network.
Quasi-peak and average are different detectors, not different limits: a source has to pass both where both are given, and a broadband or low-repetition-rate source reads very differently on the two.
CISPR 32 / EN 55032 tables are not published here. That standard is sold rather than freely published, so the analyzer carries its limit values and clause numbers from cross-checked public sources and does not reproduce its text.