Device for electromagnetic interference measurements

The device is of the type comprising a closed test cell the periphery of which is defined by an outer conductor of a TEM waveguide constituted by a tubular casing (10). An inner conductor (12) of the waveguide extends within the cell. The casing (10) has at least one intermediate portion (22) of uniform rectangular cross-section, in which there is a test region (24) for accommodating an object under test. At least in the intermediate portion (22), the inner conductor (12) has a substantially arcuate transverse profile, the concave side of which faces the object under test. The inner conductor (12) is preferably constituted by an array of transversely spaced-apart parallel wires (14) arranged so that the array has the said arcuate profile.