NAMAS-accredited microwave permittivity/permeability measurement system

A laboratory quality system has been implemented to control the measurement of complex permittivity and permeability for solid materials at microwave frequencies using a vector network analyser and S-parameter test set. The permittivity and permeability are derived from the measured S-parameters using a transmission line method. The system is designed to meet the requirements of the ISO 9000 and NAMAS accreditation standards to provide internationally-recognised measurement traceability to national standards. Also presented are the preliminary results of a measurement intercomparison with the National Physical Laboratory. Whereas a good level of agreement is observed, the comparison has identified a number of adjustments that can be made to the test procedure to improve best practice