title: Small integrating meter for assessing long-term exposure to magnetic fields.
abstract: A small, lightweight meter has been developed for magnetic-field measurements, particularly those needed for exposure-assessment purposes. This meter, known as the AMEX-3D, continuously measures all three axes of magnetic-flux density and electronically combines the data into a single estimate of cumulative exposure to the root-mean-square (rms) resultant flux density. The AMEX-3D weighs about 120 g, measures 2.7 cm x 5.1 cm x 10.2 cm, and is battery powered. Two panel-mounted jacks are provided for measuring battery voltage and for reading cumulative exposure data from the unit. The instrument has, within 3 dB, a flat response to magnetic flux densities at all frequencies in its 30-1,000 Hz bandwidth. A detailed analysis of error sources in the AMEX-3D leads to an estimate of +/- 20% as the accuracy of the instrument over its dynamic range, which extends from 0.02 to 15 microT. The AMEX-3D was tested in the field by asking electric-utility distribution linemen to wear AMEX-3D and EMDEX meters simultaneously while working. Agreement between the two measures of exposure was excellent.
authors.affiliation: Enertech Consultants, Campbell, CA 95008.
authors.forename: W T
authors.initials: WT
authors.lastname: Kaune
authors.forename: J C
authors.initials: JC
authors.lastname: Niple
authors.forename: M J
authors.initials: MJ
authors.lastname: Liu
authors.forename: J M
authors.initials: JM
authors.lastname: Silva
mesh_terms: D004574:Electromagnetic Fields; D004781:Environmental Exposure; D004867:Equipment Design; D013997:Time Factors