ETS-Lindgren HI-3627 ELF Magnetic Field Meter - Manual (Page 9)

HI-3627 Manual Page --1
1.0 Description
The HI-3627 ELF Magnetic Field Meter is designed to measure
the flux density of magnetic fields in the frequency range of 5
Hz to 2 kHz. This conforms with recent measurement guidelines
issued in Sweden for extremely-low-frequency (ELF) magnetic
fields produced by video display terminals (VDTs). The HI-3627
finds application in the measurement of magnetic fields
associated with electric power lines, electrically operated
appliances and VDTs.
The HI-3627 is a three axis flux density meter designed to be
responsive to either sinusoidal or complex magnetic field
waveforms such as produced by the vertical deflection systems
of VDTs. It computes the root-mean-square (RMS) value of
magnetic flux density and directly displays it on an analog
meter. The sensor consists of three multiturn loops connected
to the instrumentation readout package via a 1.2 meter long
cable. The microprocessor in the meter continually computes the
magnitude of the field independent of the probe orientation. This
allows quick assessment of the actual flux density value while
conveniently holding the instrument for easy meter reading. This
feature makes the HI-3627 especially useful for rapid, large area
surveys of magnetic fields.
The field sensor is electrically shielded making the response of
the HI-3627 immune to most electric field effects. No
interference is caused by ambient electric fields such as might
be found beneath high voltage, overhead electric power lines or
nearby radio or television stations.
The HI-3627 has a wide dynamic measurement range. This
provides for readings from 0.2 milligauss to 20 gauss. This large
dynamic range makes the HI-3627 convenient for measurement
of ambient residential magnetic fields as well as high level fields
found near high current carrying conductors or electrical
machinery.