User`s manual

7800 Series Hysteresisgraph System User's Manual
Operation 4-5
System Setup (Continued)
Mode 1 EEPROM Values Mode 1 calibration begins with retrieval of H an B coil calibration data from
the EEPROMS in the probe connectors. Mode 1 is the simplest method,
requires minimal user intervention, offers less chance for human error, and is
unaffected by temperature change. However, it does rely on sensing coil
stability. Because subtle changes in sensing coil geometry can occur over time,
periodic verification with reference permanent magnets is required.
Mode 2 Air Flux Mode 2 calibration is intermediate in complexity and determines H and B coil
sensitivities against a calibrated electromagnet field. The combined effect of
air gap flux, physical coil sensitivity, fluxmeter integration, area
compensation, and loading impedance determines calibration sensitivity.
Because the coil and fluxmeter are calibrated together, coil geometry changes
and electronic variations are minimized.
Mode 3 Material Standard Mode 3 calibrates to a physical flux reference standard in addition to the
Mode 2 calibration procedure. Reference standards of high purity nickel or
other materials that are traceable to known and accepted standards are
generally used. use of a standard that approximates dimensions of test samples
minimizes geometry-based distortion in the measurement process.
(B-H), H Coaxial/Concentric Surrounding Coils (Hall Probe for CAL only.) An air core sensing probe
with a B coil and two H coils (H1 and H2). The B coil and one H coil is electrically subtraced
from each other to create a (B-H) coil. ((B-H) = B – H) The flux from these coils (B-H and H)
will be separately integrated into B-H and H. Next, (B-H) and H will be mathematically summed
to form B.
B, H Coaxial/Concentric Surrounding Coils (Hall Probe for CAL only.) An air core sensing probe with a
B coil and two H coils. The two H coils, H1 and H2 are electrically subtracted from each other
to create an Hdiff coil. (H diff = H2-H1) The flux from these coils (B and Hdiff) will be
separately integrated into B and H. Next, B and H will be mathematically summed to form B-H.
B, H Embedded Pole Coil + Hall Probe for H An Fe core sensing Probe with two coils (B and H)
embedded into an Fe poletip. The two embedded coils, B and H are electrically subtracted from
each other to create a (B-H) coil. The flux from the resultant (B-H) coil will be integrated by a
single fluxmeter. H will be acquired via a Hall effect probe and Gaussmeter. B-H and H will be
mathematically summed to form B. (B = (B-H) + H)
(B-H) Side by Side Coil + Hall Probe for H An air core sensing Probe with two coils (B and H) oriented in
a side-by-side configuration. The two coils, B and H, are electrically subtracted from each other
to create a (B-H) coil. The flux from the resultant (B-H) coil will be integrated by a single
fluxmeter. H will be acquired via a Hall effect probe and Gaussmeter. B-H and H will be
mathematically summed to form B. (B = (B-H) + H)