Lake Shore 460, Руководство пользователя

Страница: 119 / 132

Lake Shore Model 460 Gaussmeter User’s Manual
Glossary of Terminology A-3
gilbert (Gb) . A cgs electromagnetic unit of the magnetomotive force required to produce one maxwell of magnetic flux in
a magnetic circuit of unit reluctance. One gilbert is equal to 10/4
π
ampere-turn. Named for William Gilbert (1540 – 1603),
an English physicist who hypothesized that the Earth is a magnet.
gilbert per centimeter . Practical cgs unit of magnet intensity. Gilberts per cm are the same as oersteds.
Greek alphabet . The Greek alphabet is defined as follows:
Alpha
α Α
Iota
ι Ι
Rho
ρ Ρ
Beta
β Β
Kappa
κ Κ
Sigma
σ Σ
Gamma
γ Γ
Lambda
λ Λ
Tau
τ Τ
Delta
δ ∆
Mu
µ Μ
Upsilon
υ Υ
Epsilon
ε Ε
Nu
ν Ν
Phi
φ Φ
Zeta
ζ Ζ
Xi
ξ Ξ
Chi
χ Χ
Eta
η Η
Omicron
ο Ο
Psi
ψ Ψ
Theta
θ Θ
Pi
π Π
Omega
ω Ω
ground . A conducting connection, whether intentional or accidental, by which an electric circuit or equipment is connected
to the earth, or to some conducting body of large extent that serves in place of the earth. Note: It is used for establishing
and maintaining the potential of the earth (or of the conducting body) or approximately that potential, on conductors
connected to it, and for conducting ground current to and from the earth (or of the conducting body).
2
H . Symbol for magnetic field strength. See Magnetic Field Strength.
Hall effect . The generation of an electric potential perpendicular to both an electric current flowing along a thin conducting
material and an external magnetic field applied at right angles to the current. Named for Edwin H. Hall (1855 – 1938), an
American physicist.
Hall mobility . The quantity µ
H
in the relation µ
H
= R
σ
, where R = Hall coefficient and
σ
= conductivity.
2
Helmholtz coils . A pair of flat, circular coils having equal numbers of turns and equal diameters, arranged with a common
axis, and connected in series; used to obtain a magnetic field more nearly uniform than that of a single coil.
1
hertz (Hz) . A unit of frequency equal to one cycle per second.
hole . A mobile vacancy in the electronic valence structure of a semiconductor that acts like a positive electron charge with
a positive mass.
2
hysteresis . The dependence of the state of a system on its previous history, generally in the form of a lagging of a
physical effect behind its cause.
1
Also see magnetic hysteresis.
IEEE . Institute of Electrical and Electronics Engineers.
IEEE-488 . An instrumentation bus with hardware and programming standards designed to simplify instrument interfacing.
The addressable, parallel bus specification is defined by the IEEE.
initial permeability . The permeability determined at H = 0 and B = 0.
initial susceptibility . The susceptibility determined at H = 0 and M = 0.
integrator . A circuit or network whose output waveform is the time integral of its input waveform.
1
international system of units (SI) . A universal coherent system of units in which the following seven units are
considered basic: meter, kilogram, second, ampere, kelvin, mole, and candela. The International System of Units, or
Système International d'Unités (SI), was promulgated in 1960 by the Eleventh General Conference on Weights and
Measures. For definition, spelling, and protocols,
see Reference 3 for a short, convenient guide.
interpolation table . A table listing the output and sensitivity of a sensor at regular or defined points which may be
different from the points at which calibration data was taken.
intrinsic coercivity . The magnetic field strength (H) required to reduce the magnetization (M) or intrinsic induction in a
magnetic material to zero.
intrinsic induction . The contribution of the magnetic material (Bi) to the total magnetic induction (B).
B
i
= B – µ
0
H (SI) B
i
= B – H (cgs)
isolated (neutral system). A system that has no intentional connection to ground except through indicating, measuring, or
protective devices of very-high impedance.
2
Kelvin (K) . The unit of temperature on the Kelvin Scale. It is one of the base units of SI. The word “degree” and its symbol
(°) are omitted from this unit. See Temperature Scale for conversions.
Kelvin Scale . The Kelvin Thermodynamic Temperature Scale is the basis for all international scales, including ITS-90. It
is fixed at 2 points: the absolute zero of temperature (0 K), and the triple point of water (273.16 K), the equilibrium
temperature that pure water reaches in the presence of ice and its own vapor.
line regulation . The maximum steady-state amount that the output voltage or current will change as the result of a
specified change in input line voltage (usually for a step change between 105–125 or 210–250 volts, unless otherwise
specified).
line of flux . An imaginary line in a magnetic field of force whose tangent at any point gives the direction of the field at that
point; the lines are spaced so that the number through a unit area perpendicular to the field represents the intensity of
the field. Also know as a Maxwell in the cgs system of units.
line voltage . The RMS voltage of the primary power source to an instrument.