   Home > Material > Terms & Definitions           Terms & Definitions Core-Tech Soft Ferrite Materials Static Magnetization curves Relative Loss Factor Vs Frequency Inductance Change Vs Temperature
EMI (Electromagnetic Interference)
A useful definition of EMI noise is any signigicant signal energy that causes unintended, undesirable circuit function or inadequate EMC performance.

AC Initial Permeability (μiac)
This is the limit value of magnetic core permeability at the origin of the virgin magnetization curve. It's given by the following formula: Inductance (L):
The magnetic flux linkages in Maxwells-turns per ampere of magnetizing current.  Inductance Factor (AL)
Inductance factor is defined as the self inductance per unit turn of a coil of a given shape and dimension wound on a magnetic core, and is determined by the following formula: Quality Factor (Q):
The efficiency of an inductor, that is the ratio of series inductive reactance to loss resistance. Loss factor (tanδ):
Deviation from ideal phase angle (90°) due to losses.  Relative Loss Factor (tanδ /μiac)
Losses per unit of permeability. Figure merit of a material. Curie Temperature (Tc):
emperature at which a ferromagnetic material loses its ferromagnetism and becomes paramagnetic(μ approaches 1)

Relative Temperature Coefficient of lnitial permeability (αμr):
This is the value obtained by dividing the temperature coefficient of the initial permeability(αμ) by the initial permeability. Specific Gravity (d)
It's calculated from its volume and weight, as shown below: CORE-TECH CORPORATION FACTORY : NO. 238-6, SHIAH CHUANG TZE, YEONG AN, HSIN WU, 327, TAO YUAN, TAIWAN, R.O.C. TEL : 886-3-4861211~3 , 4862437 , 4861198 FAX : 886-3-4861210 E-mail : coretech@tpts1.seed.net.tw WEB : http://www.coretech-taiwan.com WEB : http://www.coretechweb.com.tw 