AS NZS IEC-60331-2-2021 pdf download.Electromagnetic compatibility (EMC) Part 4.3: Testing and measurement techniques — Radiated, radio- frequency, electromagnetic field immunity test.
6 Test equipment
6.1 Test instrumentation The following types of test equipment are recommended:
– Anechoic chamber: of a size adequate to maintain a uniform field of sufficient dimensions with respect to the equipment under test (EUT). Additional absorbers may be needed to damp reflections.
– EMI filters: care shall be taken to ensure that the filters introduce no additional resonance effects on the connected lines.
– RF signal generator(s): capable of covering the frequency band of interest and as a minimum being capable of amplitude modulation as specified in Table 2. The use of low-pass or band-pass filters can be necessary to avoid problems caused by harmonics.
– Power amplifiers: to amplify the signal (unmodulated and modulated) and provide antenna drive to the necessary field level.
– Field generating antennas: biconical, log periodic, horn, combination of antennas or any other linearly polarized antenna system capable of satisfying frequency requirements (see Annex B).
– Isotropic field sensor: with adequate frequency range and sensitivity to measure the generated field strength (see Annex K about the calibration method for E-field probes).
– Power measurement device for the forward power: a directional coupler and a power meter may be used, or a forward power detector or monitor could be inserted between amplifier and antenna.
– Associated equipment to record the power levels: necessary for the required field strength and to control the generation of that level for testing. Care shall be taken to ensure adequate immunity of the test instrumentation. For the measurement uncertainty due to test instrumentation see Annex J.
6.2 Description of the test facility Because of the magnitude of the field strengths generated, the tests shall be made in a shielded enclosure in order to comply with various national and international laws prohibiting interference with radio communications. In addition, since most test equipment used to collect data is sensitive to the electromagnetic field generated during the execution of the immunity test, the shielded enclosure provides the necessary “barrier” between the EUT and the required test instrumentation. Care shall be taken to ensure that the interconnection wiring penetrating the shielded enclosure is adequately isolated from the conducted and radiated emission and preserves the integrity of the EUT signal and power responses. The test facility typically consists of an absorber-lined shielded enclosure large enough to accommodate the EUT whilst allowing adequate control over the field strengths. This includes anechoic chambers or modified semi-anechoic chambers, an example of which is shown in Figure 2. Associated shielded enclosures should accommodate the field generating and monitoring equipment, and the equipment which exercises the EUT. Further guidance on the use of anechoic chambers is given in Annex C.AS NZS IEC-60331-2 pdf download.