Iron(II) sulfide or ferrous sulfide (Br.E. sulphide) is a chemical compound with the formula FeS. In the oil/gas industry, iron sulfides are often present in a sour system due to reaction between corrosion products and hydrogen sulfide.
A material that conducts (see conduction) electricity poorly or not at all. If a voltage is applied to a dielectric, the atoms in the material arrange themselves in such a way as to oppose the flow of electric current. Glass, wood, and plastic are common dielectrics. (See insulator.)
The dielectric strength is normally expressed in volt/mm; the voltage at which the insulator breaks down, divided by the thickness in millimeters. Measuring the dielectric strength of a material, for example paper, includes the following: (source: Buckleys URVAL, Ltd .).