AS 2344:2016 pdf free.Limits of electromagnetic interference from overhead a.c. powerlines and high voltage equipment installations in the frequency range 0.15 MHz to 3000 MHz.
6 MEASURING APPARATUS
The measuring apparatus shall conform to the requirements of CISPR TR 1 8-2 and the relevant clauses of AS/NZS CISPR 16.1.1. The quasi-peak detector shall be used for all measurements below 1000 MHz; above 1000 MHz, the average detector shall be used.
7 TEST METHODS
The method of test shall be in accordance with CISPR TR 18-2, except that the following shall apply:
(a) Measurement frequency
At and below 30 MHz, measurements may be made at or near the following frequencies: 0.15 MHz, 0.25 MHz, 0.5 MHz, 1.0 MHz, 1.5 MHz, 3.0 MHz, 6.0 MHz, 10 MHz, 1 5 MHz and 30 MHz, care being taken to avoid other forms of interference and intentional transmissions provided that the disturbance is broad band only. If the disturbance noise is irregular, the peak and average measured levels at all frequencies shall be recorded and the quasi-peak levels at the 10 highest excursions. At and above 30 MHz only the peak and 10 highest quasi-peak excursions need be recorded.
NOTE: A suitable method for the identification of radio disturbance originating from power equipment, is to monitor the video detector output of the interference measuring set using an oscilloscope with its tirnebase locked to the powerline frequency and noting the presence of the interference impulses while tuning the receiver. When battery-operated equipment is used, a loop antenna, coupled to a broadband operational amplifier, will normally provide an adequate power frequency signal level to externally synchronize the tirnebase. A more rapid but less conclusive search can be performed by audibly monitoring the measuring set output.
(b) Antenna
For measurements below 30 MHz, the antenna shall be an electrically screened square or circular loop enclosing an area of approximately 0.36 m conforming with AS/NZS 16.1.1 and CISPR TR 18-2.
At frequency ranges from 30 MHz to 1000 MHz, the antenna used shall be a dipole-like antenna designed to measure the E-field, and the free-space antenna factor shall be used. The antenna types include— (i) tuned dipole antennas, whose element pairs are either straight rods or conical in shape; (ii) dipole arrays such as the log-periodic dipole array (LPDA) antennas, comprising a series of staggered sets of straight rod elements; and (iii) hybrid antennas.
Measurements above I GHz shall be made using calibrated, linearly polarized antennas. Examples are LPDA antennas, double-ridged guide horns and standard gain horns.
The antenna shall be rotated and tilted for the maximum reading, and placed next to both the transmission tower (cable attachment point) and the centre of the transmission cable span between two towers. The antenna locations and the HV power transmission line/corridor are shown in Figures 4 and 5.
Where the sensitivity of the measuring system is inadequate and the measurement is performed in the far field, a I m vertical rod antenna may be used, however, the distance correction given herein for lateral attenuation does not apply.
The attenuation law of the electric field may vary from site-to-site according to ground conditions. The rod antenna shall not be used in close proximity to lines or equipment operating at or above 220 kV and shall have a minimum spacing of 15 m to the nearest conductor.
Above 30 MHz and below 1000 MHz, the antenna shall be a broadband dipole, or a broadband dipole and a log-periodic antenna or a broadband antenna conforming to the requirements of AS/NZS CISPR 16.1.1. Above I GHz, the antenna shall be a double ridged waveguide horn.
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Where practical, the measurement of overhead powerlines shall be performed at the corridor boundary as shown in Figure 4. If the measurement cannot be made at the corridor boundary the measurement shall be made at another distance and a correction applied using the formula given in Equation 7(1).
Measurements are to be taken on both sides of an overhead line. If the measurements at two or more frequencies to the one side are consistently within 3 dB of the other, or are consistently higher to one side, then all measurements may be taken on that one side only.
The protection distance (or corridor) will be determined by the relevant regulatory authority. Where no regulation applies, the corridor edge shall be defined by the smaller of— (I) the edge of the easement or the distance given in Table 3 if an easement does not exist; or
(ii) the closest approach of a permissible building alignment; or (iii) the nearest boundary of the trafficable section of a parallel transport carriageway, cycleway or footway. If a building is or may be constructed so as to be closer to the overhead powerline above ground level, then the outer edge of the horizontal projection of the least separation shall be the corridor boundary (see Figures 2 and 3). AS 2344 pdf download.
AS 2344:2016
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