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Lake Shore Model 480 Fluxmeter User’s Manual
A-6 Glossary of Terminology
susceptibility (

) . Parameter giving an indication of the response of a material to an applied magnetic field. The
susceptibility is the ratio of the magnetization (M) to the applied field (H).

= M/H. In both SI units and cgs units the
volume susceptibility is a dimensionless parameter. Multiply the cgs susceptibility by 4

to yield the SI susceptibility.
See also Initial Susceptibility and Differential Susceptibility. As in the case of magnetization, the susceptibility is often
seen expressed as a mass susceptibility or a molar susceptibility depending upon how M is expressed.
temperature scales . See Kelvin Scale, Celsius Scale, and ITS-90. Proper metric usage requires that only kelvin and
degrees Celsius be used. However, since degrees Fahrenheit is in such common use, all three scales are delineated as
follows:
Boiling point of water
Freezing point of water
Absolute zero
kelvin Celsius Fahrenheit
0 K
273.15 K
373.15 K
–273.15 °C
0 °C
100 °C
–459.67 °F
32 °F
212 °F
Triple point of water 273.16 K
To convert kelvin to Celsius, subtract 273.15.
To convert Celsius to Fahrenheit: multiply °C by 1.8 then add 32, or: °F = (1.8 × °C) + 32.
To convert Fahrenheit to Celsius: subtract 32 from °F then divide by 1.8, or: °C = (°F. 32 )/ 1.8.
temperature coefficient, measurement . The measurement accuracy of an instrument is affected by changes in ambient
temperature. The error is specified as an amount of change (usually in percent) for every one degree change in ambient
temperature.
tesla (T) . The SI unit for magnetic flux density (B). 1 tesla = 10 4 gauss
thermal emf . An electromotive force arising from a difference in temperature at two points along a circuit, as in the
Seebeck effect. 1
tolerance . The range between allowable maximum and minimum values.
turns (N) . One complete loop of wire. In the Model 480, the turns of a coil must be entered to perform flux measurements
in units of Volt seconds (V·s

), Webers (Wb

), or Maxwells (Mx

).
Underwriters Laboratories (UL) . An independent laboratory that establishes standards for commercial and industrial
products.
unit magnetic pole . A pole with a strength such that when it is placed 1 cm away from a like pole, the force between the
two is 1 dyne.
vector . A quantity that has both magnitude and direction, and whose components transform from one coordinate system
to another in the same manner as the components of a displacement. Also known as a polar vector.
1
volt (V) . The difference of electric potential between two points of a conductor carrying a constant current of one ampere,
when the power dissipated between these points is equal to one watt.
2
volt-ampere (VA) . The SI unit of apparent power. The volt-ampere is the apparent power at the points of entry of a single-
phase, two-wire system when the product of the RMS value in amperes of the current by the RMS value in volts of the
voltage is equal to one.
2
volt·second (v·s) . A voltage of 1 volt (V) present at the input of a fluxmeter for 1 second (s) results in a reading of
1 volt·second (v·s). Volt·seconds are the primary unit of measurement for an integrator. See Weber.
watt (W) . The SI unit of power. The watt is the power required to do work at the rate of 1 joule per second. 2
weber (Wb) . The unit of magnetic flux in the mks system, equal to the magnetic flux which, linking a circuit of one turn,
produces in it an electromotive force of 1 volt as it is reduced to zero at a uniform rate in 1 second. 1
References:
1
Sybil P. Parker, Editor. Dictionary of Scientific and Technical Terms: Fifth Edition . New York: McGraw Hill, 1994
(IBSN 0-07-042333-4).
2 Christopher J. Booth, Editor. The New IEEE Standard Dictionary of Electrical and Electronic Terms: IEEE Std 100-1992, Fifth
Edition. New York: Institute of Electrical and Electronics Engineers, 1993 (IBSN 1-55937-240-0). Definitions printed with permission
of the IEEE.
3 Nelson, Robert A. Guide For Metric Practice, Page BG7 - 8, Physics Today, Eleventh Annual Buyer’s Guide, August 1994
(ISSN 0031-9228 coden PHTOAD)