Investigation of the calibration procedure from CISPR 25, Annex B, for use with vehicle component testing

CISPR 25 testing is intended to protect receivers installed in vehicles from disturbances produced by conducted and radiated emissions. The radiated emissions testing is performed in an absorber-lined shielded enclosure (ALSE). Annex B of CISPR 25 describes a calibration procedure for an ALSE, by comparing measurements in the ALSE to measurements at an open area test site (OATS). The maximum error caused by reflected energy in the ALSE is limited to 6 dB. The research for this paper began as an attempt to qualify ALSE sites for compliance testing. Suggestions for further research and for changes to the procedure were generated.