The Model 4080 is the first economical,
handheld, triaxial magnetic field meter
available for the measurement of Extremely
Low Frequency (ELF) magnetic fields. The
Model 4080 allows the user to make quick,
accurate spot field measurements from a
variety of ELF sources, including AC power
lines, office equipment, video display
terminals (VDTs), household appliances, and
all types of electrical and electronic
equipment.
The Model 4080 measures a wide range of
ELF magnetic fields,
independent of
measurement angle
. The instrument uses
three internal sensors and a microprocessor
to accurately compute and display the vector
magnitude of the magnetic field in milligauss
(or microtesla). The autoranging feature
adjusts the instrument to the proper scale,
yielding a wide measurement range of 0.1 to
511 mG (0.01 to 51.1
µ
T). The typical
accuracy error is less than 2%, sufficient for
characterizing all electrical and electronic
equipment.
The instrument comes complete with a
padded, durable carrying case, and a full
one-year warranty, covering both parts and
labor.
Note:
The term “magnetic field” is used
loosely throughout the manual. All
references to magnetic field levels in this
manual actually refer to the “magnetic flux
density”, which is measured in (CGS) units of
milligauss (mG) or (SI) units of microtesla
(
µ
T).
Possible health effects associated with the
exposure to ELF magnetic fields have been
reported in scientific literature. Although
evidence of direct cause and effect between
ELF magnetic f i e l d s a n d h e a l t h
p r o b l e m s h a s n o t b e e n established,
many respected authorities recommend
“prudent avoidance” of ELF magnetic fields
until further research leads to more
conclusive results.
For more information on the subject of ELF
magnetic fields, see the references listed at
the end of this manual.
OPERATING INSTRUCTIONS
Turning the Instrument On:
To operate the
Model 4080, first flip the ON/OFF switch to
the UP (ON) position. The instrument will
perform a self test and display “-8.8.8” for
approximately one second, verifying proper
operation.
Operation:
After the power-on sequence
has finished, the display will indicate the
magnetic field reading, in mG (instruments
ordered with Option T display the magnetic
field level in
µ
T). Simply bring the instrument
into the vicinity of ELF magnetic fields and
note the magnetic field level. As a result of
its inherent 3-axis method of measurement,
the Model 4080 eliminates the measurement
error due to improper instrument orientation.
Unlike single-axis meters, no special
handling or orientation is necessary to obtain
an accurate reading.
Battery Replacement:
Under normal
operating conditions, the unit will provide
approximately 40 hours of continuous use
using a standard 9V alkaline battery. When
the battery level falls below 5.4V, a low
battery indication (signaled by a minus sign)
will appear. Approximately one additional
hour of measurement time is available before
accuracy will become degraded. When
replacing, use only an alkaline battery.
!
Make sure the ON/OFF switch is in
the “OFF” position before replacing
the battery.
Dead Battery:
If, after turning the instrument
on, either nothing h a p p e n s o r the unit
behaves in an u n p r e d i c t a b l e fashion, try
replacing the battery. If this solves the
problem, it may be that the instrument was
left on accidentally for an extended period of
time, resulting in a “dead” battery.
TECHNICAL DESCRIPTION
This section describes some of the technical
properties of the Model 4080. The
information below explains how the Model
4080 measures magnetic fields.
Magnetic fields are created by electrical
current. They have two basic properties:
their strength (or level) measured in mG or
µ
T, and their direction. Magnetic fields form
closed, continuous loops around currents,
and are therefore, 3-dimensional in nature.
There are three orthogonal magnetic field
sensors (one for each dimension) located
internal to the Model 4080 just below the
F.W. Bell logo. If the three components of
the magnetic field are labeled Bx, By, and
Bz, then the resultant field is calculated by
the microprocessor as:
The display will indicate the magnetic field
level, B. Rotating the instrument will not
result in a changing field indication, as long
as the magnetic field is constant across the
dimensions of the internal sensors. Some
degree of directionality will be observed in
near fields (i.e., where the magnetic field
level changes rapidly over distances
comparable to the dimensions of the
instrument). In far fields, where the magnetic
field is essentially constant, directionality of
the instrument is typically less than
±
2%.
Calibration:
The Model 4080 has been
calibrated in accordance with Sypris Test &
Measurement Quality Assurance manual and
is traceable to the National Institute of
Standards and Technology (NIST). The
Sypris Test & Measurement quality system is
registered to ISO 9001:2000 and the
calibration was performed in compliance with
MIL-STD-45662A. For maximum continued
accuracy the 4080 should be calibrated
annually.
