Immittance and Material Constants A Survey

Immittance is not a quantity it is the general term of both impedance and admittance, and in a specific case a quantity must be chosen either impedance [Q] or admittance [S]. Such quantities with names ending on —ance are dependent on sample and electrode geometries. Quantities with names ending on —ivity such as impedivity [Qm], admittivity [S/m], and permittivity 0 /m] are material constants. 

If the capacitance of the empty (no dielectric material) cell is Ce (pure capacitance), it is possible to express some interesting relationships  

Usually a material is characterized with parameters for volume properties. 

Density in physics means the number of items constrained to a defined space (e.g., number of electrons in a volume or on a surface or along a line). 

Even if a material is often characterized with variables for volume properties, an epithelium or antistatic coating may have a high resistivity with respect to the substrate. 

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