ABSTRACT

CONTENTS 11.1 Objectives and Limitations............................................................................................ 381

11.1.1 Dosimetry........................................................................................................... 382 11.1.2 Densitometry or Incident Exposure Assessment ........................................ 383

11.2 Fundamental Quantities of EMF.................................................................................. 384 11.2.1 Primary Quantities: Basic Restrictions .......................................................... 385 11.2.2 Derived Quantities: Reference Levels or Maximum Permissible

Exposure............................................................................................................. 386 11.3 Experimental Techniques .............................................................................................. 386

11.3.1 Field Probes ....................................................................................................... 386 11.3.1.1 Broadband E Field Probes.............................................................. 386 11.3.1.2 Electro-Optical Sensors ................................................................... 389

11.3.2 Temperature Instrumentations....................................................................... 391 11.3.2.1 Temperature Probes ........................................................................ 391 11.3.2.2 Infrared Photography...................................................................... 392 11.3.2.3 Microcapsulated Thermo-Chromic Liquid Crystals .................. 393 11.3.2.4 Calorimeters...................................................................................... 393

11.3.3 Measurement Antennas................................................................................... 393 11.4 Near-Field Scanners ....................................................................................................... 394

11.4.1 Scanners for Dosimetric Compliance Testing .............................................. 394 11.4.2 Fast Dosimetric Scanners................................................................................. 395 11.4.3 Incident Near-Field Scanners.......................................................................... 397

11.5 Incident Field Evaluations in the Far Field of Transmitters.................................... 398 11.5.1 Broadband Measurements............................................................................... 399 11.5.2 Frequency-Selective Measurements............................................................... 401 11.5.3 Code-Selective Measurements ........................................................................ 402

11.6 Typical Maximum Peak Spatial SAR Exposures....................................................... 402 11.7 Typical Far-Field Exposures ......................................................................................... 404 Acknowledgment....................................................................................................................... 405 References ................................................................................................................................... 405

Experimental electromagnetic field (EMF) exposure assessments can be divided into two categories: (1) densitometry, that is, quantification of the incident EMF or the field characteristics at the location of exposed bodies but without their presence, and (2)

dosime try, that is, quantif ication of the EMF indu ced in biologic al tissues or bodie s. In mos t cases of compl iance eva luation , verificati on that the actual exp osure is below a certain value is par amount to accura te determi nation of the ind ividual exp osure. However , highly accura te pr ediction s are need ed for som e med ical appli cations, for instan ce, hype rthermia. The focus of this chapte r is on dosime try for freque ncies ab ove 10 MHz , often referre d to as radio freque ncy (RF) dosimetr y. At low er frequ encies, experi menta l dosime try is usual ly limited to measu rement of the incide nt magn etic fields.