Helmholtz Coil Systems
B
artington Instruments has now
added Helmholtz coil systems to
its range. These generate precise
magnetic fields ideal for calibration of
magnetometers and compasses, and
are currently used at Bartington’s own
calibration facility.
Helmholtz coils are available in several
diameters, from 350mm to 2m. These
are supported by a power amplifier and
complete control system compatible
with every coil in the range. Operating
in DC and AC, the three-channel power
amplifier delivers up to 29A at DC and
frequencies up to 5kHz. Amplitudes and
frequencies are coil-dependent, with
smaller coils achieving fields exceeding
1mT at DC, and in excess of 100µT at
5kHz.
The control system can be expanded to
include a closed-loop control mod-
ule. This provides active feedback for
cancellation of external field variations,
making it possible to use the coils in a
manufacturing environment. A precise
fluxgate sensor is also used as part of
the closed-loop system to monitor field
disturbances within the coil, achieving
field stability of a few nT.
The system may be computer con-
trolled via the addition of a National
Instruments™ data acquisition card
and LabVIEW™ software. By using
source code that we provide, you
can adapt the software to your exact
requirements, enabling seamless inte-
gration into your testing and manufac-
turing procedures.
These systems benefit from reduced
orthogonality errors, which facili-
tates precise calibration of optical
range-finding equipment, magnetic
field sensors and compasses inside
consumer electronics, and magneto-
meter packages found in oil and gas
industry directional drilling tools. The
larger coils in the range are suitable
for calibration and testing of satellite
subassemblies and CubeSats.
In addition to Helmholtz coil systems,
Bartington Instruments also provides
equipment for magnetic field surveys
of proposed installation sites, in order
to achieve the best possible system
performance.
www.bartington.com
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