Holaday Industries HI-3624 User Manual - page 13
HI-3624 / HI-3624A Manual
Page 5
Operation
The ELF magnetic field sensor must be plugged into the HI-3624
meter case for proper operation; it makes no difference whether
the sensor is plugged in before or after the meter is turned on.
A single switch controls the entire operation of the HI-3624
(except for the model HI-3624A, in which case one additional
switch controls the desired low frequency cutoff). The main
switch turns on the instrument and selects one of five ranges
for measurement. A "Low Battery" LED glows when the
batteries are low. If the "low Battery" indicator remains on
replace both of the batteries which are accessible from the back
side of the meter case. It is normal for the LED battery indicator
to briefly blink during turning the switch to various ranges and
when turning the instrument off.
When beginning field measurements, successively turn the
range switch to the right, increasing the instrument's sensitivity
until an upscale reading on the meter is obtained. Most accuracy
is achieved when the meter reads approximately midscale. At
each range setting, while holding the meter in one hand, rotate
the sensor with the other hand so as to obtain a maximum
indication on the meter.
Because the sensor is capable of measuring only one polarization
component of the magnetic field at any specific time, there are
two methods that can be used for measurements. In the
majority of cases, it is sufficient to orient the sensor so that a
maximum indication on the meter is observed. In many
instances this will be a measurement of the resultant magnetic
flux density. The sensor must be rotated about three axes
which are each perpendicular to one another. This can be
quickly accomplished with a little practice.
In other cases, the root-sum-squared resultant value of flux
density may be obtained by taking three orthogonal
measurements of the field; in this case, the sensor is
successively oriented in three mutually perpendicular directions
around a fixed point and the individual readings recorded. The
mutually perpendicular directions will be denoted as X,Y, and Z.
The resultant flux density is then found by forming the root-
sum-squared value from the individual readings as follows: