Siemens Sitrans, LC 500 instruction manual Glossary

Glossary

capacitance: the property of a system of conductors and dielectrics that permits the storage of electricity when potential differences exist between the conductors. Its value is expressed as the ratio of a quantity of electricity to a potential difference, and the unit is a Farad.

capacitor: a device in a circuit that has the potential to store an electric charge. Typically a capacitor has 2 conductors or electrodes separated by a layer of a nonconducting material called a dielectric. With the conductors on opposite sides of the dielectric layer oppositely charged by a source of voltage, the electrical energy of the charged system is stored in the polarized dielectric.

derating: to decrease a rating suitable for normal conditions according to guidelines specified for different conditions.

dielectric: a nonconductor of direct electric current.1

dielectric constant: the ability of a dielectric to store electrical potential energy under the influence of an electric field. This is measured by the ratio of the capacitance of a condenser with the material as dielectric to its capacitance with vacuum as dielectric. The value is usually given relative to a vacuum /dry air: the dielectric constant of air is 11.

immiscible: incapable of mixing or attaining homogeneity.

implicit: for example in “the units are implicit in pF”, the units are implied, or assumed to be pF, because there is no other option.

miscible: capable of being mixed.

repeatability: the closeness of agreement among repeated measurements of the same variable under the same conditions.

saturation: a condition in which any further change of input no longer results in a change of output. For example, “the loop-current will saturate to 3.8 or 20.5 if the level exceeds the Range settings”.

solid-state device: a device whose function is performed by semi-conductors or the use of otherwise completely static components such as resistors and capacitors.

stilling-well: a grounded metal tube with openings.

1.Many conductive liquids/electrolytes exhibit dielectric properties; the relative dielectric constant of water is 80.

7ML19985GE01 SITRANS LC 500 – INSTRUCTION MANUAL Page 109

Glossary