Glossary E
Earth Ground: A conductor that will dissipate large electrical currents into the Earth.

ECL: Emitter Coupled Logic. Where transistors are held in the turned-on state to increase the speed of the gate.

Electrolytic: A type of capacitor that has a liquid or paste between the plates to increase its capacitance.

Electron Flow: The direction in which electrons flow. This is from negative to positive - as electrons are negatively charged.

Electrode Potential (E): The difference in potential established between an electrode and a solution when the electrode is immersed in the solution.

Electrolyte: Any substance which, when in solution will conduct an electric current. Acids, bases, and salts are common electrolytes.

Electromotive Force (emf): The potential difference between the two electrodes in a cell. The cell emf is the cell voltage measured when no current is flowing through the cell. It can be measured by means of a pH meter with high input impedance.

Electrical Interference: Electrical noise induced upon the signal wires that obscures the wanted information signal.

EMF: Electromotive force. A rise in (electrical) potential energy. The principal unit is the volt.  e Symbol: E. Unit: volt. The property of electrical energy that causes a current to flow.

EMI: Electromagnetic interference.

Emitter: One terminal of a transistor.

Emissivity: The ratio of energy emitted by an object to the energy emitted by a blackbody at the same temperature. The emissivity of an object depends upon its material and surface texture; a polished metal surface can have an emissivity around 0.2 and a piece of wood can have an emissivity around 0.95.

Envelope: The outline of a signal's highest and lowest points acquired over many repetitions.

Environmental Conditions: All conditions in which a instruments may be exposed during shipping, storage, handling, and operation.

Eprom: Erasable Programmable Read-Only Memory. The PROM can be erased by ultraviolet light or electricity.

Equivalent-time Sampling: A sampling mode in which the oscilloscope constructs a picture of a repetitive signal by capturing a little bit of information from each repetition.
Error Band: The allowable deviations to output from a specific reference norm. Usually expressed as a percentage of full scale.

Error: The difference between the value indicated by the transducer and the true value of the measurand being sensed. Usually expressed in percent of full scale output.

Exclusive or Logic element that features two inputs. The output will be 1 only when one or the other (but not both) is logic . 1. In all other cases the output is 0.

Exothermic: Gives off heat. A process is said to be exothermic when it releases heat.