Aug 31, 2011

Application of an Induced Field Sensor for Assessment of Electromagnetic Exposure from Compact Fluorescent Lamps

Jagadish Nadakuduti, Mark Douglas, Myles Capstick, Sven Kühn, and Niels Kuster, Bioelectromagnetics, Volume 33, Issue 2, pp. 166–175, February 2012. Online August 31, 2011

The development of instrumentation and procedures for the electromagnetic exposure assessment of compact fluorescent lamps (CFLs) is investigated. The incident and induced fields from 11 CFLs have been measured in the 10 kHz–1 MHz range. Commercially available equipment was used to measure the incident fields, while a novel sensor was built to assess the induced fields in humans. Incident electric field levels significantly exceed the ICNIRP reference levels at close distances for some sources, while the induced fields are within the ICNIRP basic restrictions. Maximum current densities for CFLs are comparable to the limits (in the range of 9% to 56%), demonstrating the need for measurements to establish compliance. For the frequency range investigated, the induced fields were found to be considerably higher for CFLs than for incandescent light bulbs, while the exposure from the two LED bulbs was low. The proposed instrumentation and methods offer several advantages over an existing measurement standard, and the measurement uncertainty is significantly better than the assessment of electric and magnetic fields at close distances.

The scientific and technical impact of the study can be summarized as:

  • Scientifically sound instrumentation, methods and procedures have been developed for the EM exposure assessment of CFLs.
  • The ICNIRP reference levels can be exceeded in close vicinity of the light bulbs, and the incident fields greatly overestimate the induced exposure.  
  • Therefore, the measurement of incident fields, using standard free-space equipment or IEC 62493, is inadequate for human exposure assessment.
  • A novel induced field sensor has been developed by the authors. The induced fields are correlated to exposure in human models using numerical simulations.
  • Due to the relatively high induced fields from the tested CFLs, induced field measurements are needed to demonstrate compliance of a light bulb with the ICNIRP basic restrictions.