Immunity to radiated RF electromagnetic fields - levels 1–30 V/m from 80 MHz.
The standard specifies a method for testing equipment immunity to radiated radio-frequency electromagnetic fields. It simulates fields generated by radio sources located some distance from the equipment: radio and television transmitters, portable radios, mobile phones and other wireless devices.
In railway applications, such a source may be the driver’s radio, a GSM-R terminal or a maintenance worker’s phone used close to control cabinets.
The test demonstrates that the equipment maintains a specified function at a specified field strength over a specified frequency range. The method number is not a declaration of product conformity; field strength, frequency range and performance criterion are selected by the product or generic EMC standard.
The equipment under test is placed in an anechoic chamber within a uniform field area calibrated at 16 points (minimum area 0.5 m × 0.5 m). The carrier is amplitude-modulated with a 1 kHz sine wave at 80% depth.
Frequency is swept in steps not exceeding 1% of the preceding value, with dwell time at each frequency no shorter than the response time of the equipment and at least 0.5 s. Each face is illuminated twice, with the antenna vertically and horizontally polarized.
Results are assessed in four categories: normal operation within specification; temporary loss or degradation with automatic recovery; temporary loss requiring operator intervention; irreversible loss of function. Ed. 4.0 introduced multiple test signals, expanded guidance on equipment and cable configuration, removed the upper frequency limit and specified verification of power-amplifier linearity.
Check field strength (V/m), frequency range and performance criterion; 10 V/m corresponds to level 3 and 30 V/m to level 4. The railway EMC standard (EN 50121 series) references this test method with its own levels for rolling stock and infrastructure.
