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TELECOMMUNICATIONS (CONTROL OF INTERFERENCE) REGULATIONS - SCHEDULE 1
LIMITS OF INTERFERENCE VOLTAGE, INTERFERENCE FIELD STRENGTH, INTERFERENCE POWER, OR INSERTION LOSS FOR THE PURPOSES OF REGULATION 7
(Past version on 06/30/1997).
[regulations 2, 7 & 10]
PART I
IGNITION APPARATUS OF INTERNAL COMBUSTION ENGINES
Limits of radiated interference based on quasi-peak measurements in the frequency range 30 MHz to 1000 MHz, measured at a distance of 10 m.
Frequency Range
(MHz) |
Field Strength Limit
(Quasi-peak)
(dBμV/m) |
30-75
75-400
400-1000 |
34
45 |
Note: [1] The limit increases linearly with the logarithm of the frequency.
PART II
INFORMATION TECHNOLOGY EQUIPMENT
1. Limits of mains terminal interference voltage in the frequency range 0.15 MHz to 30 MHz for class A equipment*.
Frequency Range
(MHz) |
Interference Voltage Limit (dBμV) [1] |
Quasi-peak |
Average |
0.15 to 0.5
0.5 to 30 |
79
73 |
66
60 |
Note: [1] The lower limit shall apply at the transition frequency.
2. Limits of mains terminal interference voltage in the frequency range 0.15 MHz to 30 MHz for class B equipment**.
Frequency Range
(MHz) |
Interference Voltage Limit (dBμV) [2] |
Quasi-peak |
Average |
0.15 to 0.5
0.5 to 5
5 to 30 |
66 to 56 (3)
56
60 |
56 to 46 [3]
46
50 |
Note: [2] The lower limit shall apply at the transition frequency.
[3] The limit decreases linearly with the logarithm of the frequency.
3. Limits of radiated interference field strength in the frequency range 30 MHz to 1000 MHz at a test distance of 30 m for class A equipment*.
Frequency Range
(MHz) |
Field Strength Limit
(Quasi-peak)
(dBμV/m)(4) |
30 to 230
230 to 1000 |
30
37 |
Note: [4] The lower limit shall apply at the transition frequency.
4. Limits of radiated interference field strength in the frequency range 30 MHz to 1000 MHz at a test distance of 10 m for class B equipment**.
Frequency Range
(MHz) |
Field Strength Limit
(Quasi-peak)
(dBμV/m)[5] |
30 to 230
230 to 1000 |
30
37 |
Note: [5] The lower limit shall apply at the transition frequency.
* Equipment used or located in commercial/non-residential premises.**
** Equipment used or located in domestic/residential premises.
PART III
SOUND AND TELEVISION BROADCAST RECEIVERS
AND ASSOCIATED EQUIPMENT
Limits of conducted interference and radiated interference.
1. Limits of interference voltage injected into the mains:
Equipment
Type |
Frequency
Range
(MHz) |
Interference Voltage Limit
(dBμV) [1][2] |
Quasi-peak [3] |
Average [3] |
Sound and
television
receivers and
associated
equipment [5]
|
0.15-0.5
0.5-5
5-30 |
66-56 [4]
56
60 |
56-46 [4]
46
50 |
Note: [1] The higher value measured with and without the aerial input outer conductor
screen connected to earth is considered.
[2] At the transition frequency, the lower limit applies.
[3] If the limits for the average detector are met when using the quasi-peak detector, then the limits for the measurements with the average detector are considered to be met.
[4] Limits decreasing linearly with the logarithm of the frequency.
[5] Television receivers with teletext facilities should be tested in teletext mode with teletext picture.
2. Limits of radiated interference due to the local oscillator at its fundamental and harmonic frequencies and due to all other sources at a distance of 3 m:
Equipment
Type |
Source |
Frequency
(MHz) |
Field Strength
Limit
(dBμV/m) [6]
Quasi-peak |
Television
receivers and
video recorders
|
|
300-1000
121.5
243 |
Fundamental 56 [7]
Harmonics 56
|
Frequency
modulation
sound receivers [8]
|
|
30-300
300-1000 |
Fundamental 60
Harmonics 52
Harmonics 56
|
Note: [6] At the transition frequency, the lower limit applies.
[7] If a standard intermediate frequency is used, the limit at the local oscillator fundamental frequency of television receivers and video recorders can be relaxed to 70.
[8] For car radio receivers no radiation limits apply.
3. Limits of interference voltage at the aerial terminals:
Equipment
Type |
Source |
Frequency
(MHz) |
Interference
Voltage Limit [9][10]
(dBμV) 75 Ω
Quasi-peak |
Television
receivers and
video recorders
working in
channels between
30MHz and 1 GHz
|
|
30-950
950-1750
30-1750 |
Fundamental 46
Harmonics 46
Harmonics 54 [11]
|
Television
receivers for
broadcast satellite
transmission: tuner
units at 1st IF [12]
|
|
30-950
950-1750
30-1750 |
Fundamental 46
Fundamental 54 [11]
|
Frequency
modulation
sound receivers
|
|
30-300
300-1000
30-1000 |
Fundamental 54
Harmonics 50
Harmonics 52
|
Frequency
modulation
car radios
|
|
30-300
300-1000 |
Fundamental 66
Harmonics 59
Harmonics 52 |
Note: [9] The interference voltage limits for receivers with nominal impedance other than
75 Ω are calculated according to the following formula:
Lz = L75 + 10 log (Z/75) dBμV
where Z = nominal impedance in Ω
L75 = interference voltage limit for 75 Ω nominal impedance
Lz = interference voltage limit for Z nominal impedance
[10] At the transition frequency, the lower limit applies.
[11] The value of 54 dBμV is intended to be reduced to 46 dBμV.
[12] "1st IF" stands for "first intermediate frequency". For tuner units, "aerial terminals" (天線接線端子) means "1st IF input terminals".
PART IV
FLUORESCENT LAMPS AND LUMINAIRES
1. Minimum value of insertion loss of luminaires with or without starters designed for the following types of fluorescent lamps:
(a) linear fluorescent lamps with a nominal diameter of 15 mm, 25 mm or 38 mm;
(b) circular fluorescent lamps with a nominal diameter of 28 mm or 32 mm;
(c) U-type fluorescent lamps with a nominal diameter of 15 mm, 25 mm or 38 mm;
(d) single-capped fluorescent lamps, without integrated starter and with a nominal diameter of 15 mm.
Frequency (kHz) |
160 |
240 |
550 |
1000 |
1400 |
Minimum values of
insertion loss (dB)
|
28 |
26 |
24 |
22 |
20 |
2. Mains terminal interference voltages for all types of luminaires for which the insertion loss limits do not apply shall comply with the mains terminal voltage limits as shown in the table below. These limits shall also apply to self-ballasted fluorescent lamps.
Frequency Range |
Interference Voltage Limit [4] (dBμV) |
Quasi-peak |
Average [2] |
9 kHz-50 kHz [3]
50 kHz-150 kHz [3]
150 kHz-0.5 MHz
0.5 MHz-5 MHz
5 MHz-30 MHz
|
|
|
Note: [1] The limit decreases linearly with the logarithm of the frequency in the ranges 50
kHz to 150 kHz and 150 kHz to 0.5 MHz.
[2] If it is certain that only broadband interference sources are present, then the average measurements need not be made.
[3] The limit values in the frequency range may be modified at a later date.
[4] At the transition frequencies, the lower limit applies.
PART V
HOUSEHOLD ELECTRICAL APPLIANCES, SIMILAR ELECTRICAL
APPARATUS AND PORTABLE TOOLS
Limits of radio interference in the range 0.15 MHz to 300 MHz.
1. Continuous conducted interference
Limits of continuous conducted interference voltage for the frequency range 0.15 MHz to 30 MHz.
(a) Household electrical appliances and electrical apparatus causing similar interference:
Frequency Range
(MHz) |
Interference Voltage Limit (dBμV)[1] |
Quasi-peak |
Average* |
|
66-56 [2] |
59-46 [2] |
|
|
|
|
|
|
Note: [1] At the transition frequency, the lower limit applies.
[2] The voltage limit decreases linearly with the logarithm of the freguency.
(b) Electrical apparatus with regulating controls incorporating semi-conductor devices:
Frequency
Range
(MHz) |
Interference Voltage Limit (dBμV) [3] |
At mains terminals |
At load terminals and at additional terminals |
Quasi-peak |
Average* |
Quasi-peak |
Average* |
|
66-56 [4] |
56-46 [4] |
80 |
70 |
|
56 |
46 |
74 |
64 |
|
60 |
50 |
74 |
64 |
Note: [3] At the transition frequency, the lower limit applies.
[4] The voltage limit decreases linearly with the logarithm of the frequency.
(c) Portable tools
(i) with rated power of motor** not exceeding 700 W:
Frequency Range
(MHz) |
Interference Voltage Limit
(dBμV) [5] |
Quasi-peak |
Average* |
|
66-59 [6] |
59-49 [6] |
|
59 |
49 |
|
64 |
54 |
(ii) with rated power of motor** above 700 W and not exceeding 1000 W:
Frequency Range
(MHz) |
Interference Voltage Limit
(dBμV) [5] |
Quasi-peak |
Average* |
|
70-63 [6] |
63-53 [6] |
|
63 |
53 |
|
68 |
58 |
(iii) with rated power of motor** above 1000 W:
Frequency Range
(MHz) |
Interference Voltage Limit
(dBμV) [5] |
Quasi-peak |
Average* |
|
76-69 [6] |
69-59 [6] |
|
69 |
59 |
|
74 |
64 |
Note: [5] At the transition frequency, the lower limit applies.
[6] The voltage limit decreases linearly with the logarithm of the frequency.
2. Continuous radiated interference
Interference power limits for the frequency range 30 MHz to 300 MHz:
(a) Household appliances and similar apparatus:
Frequency Range
(MHz) |
Interference Voltage Limit
(dBμV) |
Quasi-peak |
Average* |
30-300 |
45-55 [7] |
35-45 [7] |
Note: [7] The power limit increases linearly with the logarithm of the frequency.
(b) Portable tools
(i) with rated mains power** up to and including 700 W:
Frequency Range
(MHz) |
Interference Voltage Limit
(dBμV) |
Quasi-peak |
Average* |
30-300 |
45-55 [8] |
35-45 [8] |
(ii) with rated mains power** above 700 W up to and including 1000 W:
Frequency Range
(MHz) |
Interference Voltage Limit
(dBμV) |
Quasi-peak |
Average* |
30-300 |
49-59 [8] |
39-49 [8] |
(iii) with rated mains power** above 1000 W:
Frequency Range
(MHz) |
Interference Voltage Limit
(dBμV) |
Quasi-peak |
Average* |
30-300 |
55-65 [8] |
45-55 [8] |
Note: [8] The power limit increases linearly with the logarithm of the frequency.
* If the average limit is met when using a quasi-peak detector receiver, the test unit shall be deemed to meet both limits and measurement with the average detector receiver need not be carried out.
** The power of any heating device is to be excluded.
3. Discontinuous interference
The limits for continuous conducted interference specified in paragraph 1, as increased by the following amount, apply-
(a) 44 dB (for N (Note 1) ＜ 0.2);
(b) 20 log 10 30/N dB (for 0.2 ≦ N ≦ 30);
(c) 0 dB (for N ＞ 30).
Note- 1. N is the click rate determined from the formula N = n/T, T being 120 minutes or
the observation time in minutes, whichever is less to produce 40 clicks (Note 2), and n being the number of clicks registered during the observation time.
2. A click is defined as a disturbance which-
(a) exceeds the maximum limit specified in paragraph 1;
(b) lasts not more than 200 ms; and
(c) is separated from a subsequent disturbance by at least 200 ms.
3. The apparatus under test shall be deemed to comply with the maximum limit if not more than a quarter of the number of clicks registered during the observation time exceed such limit.
(L.N. 153 of 1993)
"aerial terminals" (天線接線端子)
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