1. ‘Safety of medical electrical equipment. Part 1. General Requirements’;BS5724,1989
2. Section 2.3 ‘Specification for shortwave therapy equipment’;BS5724,1992
3. ‘Limits and methods of measurement of radio interference characteristics of industrial, scientific and medical radio frequency equipment (excluding surgical diathermy apparatus)’;CISPR,1976
4. ‘Guide lines on limits of exposure to radiofrequency electromagnetic fields in the frequency range from 100 kHz to 300 GHz’;International Non-lonising Radiation Committee;Health Physics,1988
5. GS11 ‘Guidance as to restrictions on exposures to time varying electromagnetic fields and the 1988 recommendations of the International Non-lonising Radiation Committee;National Radiation Protection Board,1989