Development of Near-Field Electric Energy Density Meter Model EDM-2
Donald R. Belsher · 1975
The EDM-2 meter development in 1975 helped establish scientific methods for measuring electromagnetic field exposure levels.
Plain English Summary
This 1975 technical report describes the development of the EDM-2, a specialized meter designed to measure electric energy density in near-field environments. The research focused on creating instrumentation capable of accurately detecting electromagnetic field intensity close to EMF sources. This work contributed to early efforts in quantifying electromagnetic field exposure levels.
Why This Matters
This technical development represents a crucial piece of EMF measurement history. The EDM-2 meter was designed during an era when scientists were beginning to recognize the need for precise electromagnetic field measurement tools. Near-field measurements are particularly important because they capture the highest exposure levels that occur close to EMF sources - exactly where people often find themselves with modern devices. The reality is that without accurate measurement tools like the EDM-2, we cannot properly assess exposure risks or establish meaningful safety standards. This 1975 work laid groundwork for the sophisticated EMF meters we rely on today to evaluate everything from cell phone radiation to power line emissions.
Exposure Information
Specific exposure levels were not quantified in this study.
Study Details
To develop an electric-field survey monitor (EDM-2) for measuring occupational exposure to radiofrequency (RF) radiation from 10 to 300 MHz, as no suitable monitoring instruments were available for this frequency range.
The EDM-2 monitor was constructed using a set of three orthogonal dipoles to obtain an essentially i...
The survey monitor was calibrated from 10 to 500 MHz with specific calibration points within the Fed...
The EDM-2 meter provides substantial improvement over previous meters of this type, including faster rise and fall time for pulse response, a dynamic range of 50 dB, lower noise preamplifiers, greatly reduced temperature sensitivity, and flat response from 10 MHz through 500 MHz. The monitor was calibrated at 13.56 MHz, 27.12 MHz and 40.68 MHz, with the meter calibrated to read directly at 40.68 MHz. For more accurate results at 27.12 MHz the reading must be multiplied by 1.047, and at 13.57 MHz the correction factor is 1.133.
Show BibTeX
@article{development_of_near_field_electric_energy_density_meter_model_edm_2_g4637,
author = {Donald R. Belsher},
title = {Development of Near-Field Electric Energy Density Meter Model EDM-2},
year = {1975},
}