ETS-Lindgren HI-3637 VLF Magnetic Field Meter User Manual
Page 35

HI
n
3637 Manual
Page — 27
8.0 CALIBRATION
The HI
n
3637 is calibrated using a Helmholtz coil
(consisting of two close-coupled windings) one meter in
diameter to establish an accurate, known magnetic field
flux density. A precisely controlled and measured
sinusoidal current is driven through the coils and, based
on the dimensions of the coils, the magnetic field flux
density between the coils is calculated.
Each axis is individually calibrated. Calibration is
performed at a frequency of 20 kHz, and verified at 232
kHz, at a flux density level of 10 mG. The out of band
response is checked at 60 Hz and 700 kHz. All calibration
is traceable to NIST.
The HI
n
3637 indicates magnetic flux density (B) in units
of Tesla/Gauss. The flux density in microteslas or the
magnetic field strength (H) in milliamperes per meter are
related as follows:
1 mG = 0.1 microtesla (
:
T)
1 mG = 80 milliamperes per meter (mA/m)
The recommended calibration interval is one year.
Holaday Industries offers complete calibration services
which comply with MIL
n
STD 45662A.