Also called the permittivity and denoted DK, or Er. The ratio of the capacitance of an insulator to the capacitance of a vacuum or dry air (the dielectric constant of a vacuum is 1.00000, dry air is 1.00054). Capacitors release charge when a circuit is broken. Capacitance is the ratio of charge absorbed to the potential (voltage applied). A dielectric constant of 3 means an insulator will absorb 3 times more electrical charge than a vacuum.