Glass-to-metal seal little lower than that of the soda-lime glass. Classically high lead containing glasses are used, but it is also possible to substitute these by multi-component glasses e.g. based on the system ---------. Glass-to-metal seal Glass-to-metal seals are a very important element of the construction of vacuum tubes, electric discharge tubes, incandescent light bulbs, glass encapsulated semiconductor diodes, reed switches, pressure tight glass windows in metal cases, and metal or ceramic packages of electronic components. Properly done, such a seal is hermetic (vacuum tight, good electrical insulation, special optical properties e.g. UV lamps). To achieve such a seal, two properties must
Constant phase element Constant phase element A constant phase element is an equivalent electrical circuit component that models the behaviour of a double layer, that is an imperfect capacitor. Constant phase elements are also used in equivalent circuit modelling and data fitting of electrochemical impedance spectroscopy data. A constant phase element also appears currently in modeling the behaviour of the imperfect dielectrics. The generalization in the fields of imperfect electrical resistances, capacitances and inductances leads to the general "Phasance" concept: http://fr.scribd.com/doc/71923015/The-Phasance-Concept The electrical impedance can be calculated: where the CPE admittance is: formula_2 and Q and n (0<n<1) are frequency independent. Q =