Measurement of the screening effectiveness of a large motor vehicle

A commercial vehicle was subjected to electromagnetic radiation, and the field within the cab was measured. Deductions were then made of the field anticipated at the point of measurement but without the vehicle present and thus the screening effectiveness could be determined. Observations were then made of the magnitude of any resonances which increased the in-cab strength. The commercial vehicle used for the test was of the type used for towing trailers to make an articulated combination. The tests were conducted in a semianechoic chamber which was 22 m by 10 m by 7 m high, and lined with 1.8 m absorbers. The electromagnetic field to which the vehicle was subjected was radiated from an antenna which was placed at five different positions around the vehicle. The field strength in the vehicle cab was measured by an isotropic field strength meter.<
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