ETS-Lindgren HI-3637 VLF Magnetic Field Meter - Manual (Page 17)

HI n 3637 Manual Page — 9
assistance.
Controls, Indicators and Connectors
The instrumentation is housed in a rugged aluminum
chassis. The entire unit is shipped in a convenient
carrying case. The protective foam liner inside the
carrying case has cutouts which accommodate the meter,
the detachable probe and the optional accessories offered
for the meter.
The probe consists of a sensing head containing three
orthogonal coils oriented to pick up the X, Y, and Z
components of the field. The detachable probe plugs into
the multi-pin connector mounted on top of the chassis.
The color coded label surrounding the probe connector
will match the color of the band on the probe cover.
The top of the chassis also contains a ¼ inch stereo
phone jack. The jack is used to connect the battery
charger and also provide access to the recorder output
signal.
The rotary selector switch on the HI n 3637 front panel
controls power to the instrument and selects one of five
measurement ranges. The scales are arranged so that
when turned to the first position—400 : T/4 G (or 300
Amps/meter if the optional kit is installed)—the meter is
measuring on its least sensitive scale, i.e., highest range.
As the switch is rotated clockwise, the sensitivity of the
meter increases. As a general rule, readings will be most
accurate when the meter movement shows maximum
deflection without lighting the Over Range indicator.
There are two indicators on the front panel. A "Low
Battery" LED illuminates when the battery voltage is too
low to provide accurate readings. At this point, testing
should be discontinued and the battery recharged or
replaced. The "Over Range" LED illuminates when the
measured flux density exceeds full scale for the selected
range.