18WuD2x

electrostatic transducer • element 253
electrostatic transducer See CAPACITANCE
TRANSDUCER.
electrostatic tube of flux The space between electric
lines of flux going through adjacent points on
the boundary of a given area in an electric field.
electrostatic tweeter A small electrostatic
speaker for reproducing high-frequency sounds.
Compare WOOFER.
electrostatic unit Abbreviation, esu. A unit of
measure in the electrostatic system of cgs units.
Also see CENTIMETER-GRAM-SECOND. Compare
ELECTROMAGNETIC UNIT.
electrostatic vector See ELECTRIC VECTOR.
electrostatic voltmeter An indicating meter
whose movement consists of a stationary metal
plate near a rotating metal plate. A voltage applied
to the plates charges them, and the attraction
between them causes the movable member
to rotate against the torque of a returning spring
over an arc proportional to the voltage.
Calibrated
scale
Movable
vane
Spring
bearing
electrostatic voltmeter
Fixed
vane
Input
electrostatography See XEROGRAPHY.
electrosteel See ELECTRIC STEEL.
electrostenolysis The deposition of certain metals
from a solution in capillary tubes when an electric
current passes through the solution.
electrostimulation Electrical excitation of nerves
for the relief of pain.
electrostriction In certain materials, the physical
contraction that occurs when a voltage is applied.
Compare MAGNETOSTRICTION.
electrostrictive ceramic A ceramic exhibiting
ELECTROSTRICTION when voltage is applied.
electrostrictive relay A relay in which the movable
contact is carried by a bar of electrostrictive
material, such as barium titanate. A control voltage
deforms the material, causing the contacts to
close.
electrosurgery Surgery, sometimes bloodless,
achieved with diathermy-like equipment. See
DIATHERMY, 2.
electrosynthesis Chemical synthesis produced by
means of electric currents or fields.
electrotape Also called electronic tape measure.
Any device that measures distance by electronic
means, such as radar or sonar.
electrotechnology See ELECTRICAL TECHNOL-
OGY and ELECTRONICS TECHNOLOGY.
electrotellurograph An instrument for measuring
ground currents.
electrotherapeutics See ELECTROTHERAPY.
electrotherapy The treatment of disorders or diseases
by electrically induced heat—especially by
DIATHERMY.
electrothermal 1. Pertaining to electrically generated
heat. 2. Pertaining to a combination of electricity
and heat.
electrothermal device A device whose operation
depends on the heat generated by an electric current
(e.g., a bolometer, hot-wire ammeter, thermocouple,
or varistor).
electrothermal expansion element A thermostatic
element, such as a bimetallic strip, whose
expansion is used in heat-sensitive switches.
electrothermal instrument A hot-wire or thermocouple-type
meter.
electrothermal recorder See ELECTRIC RE-
CORDING, 1 and THERMAL RECORDER.
electrothermic See ELECTROTHERMAL.
electrothermics The study and application of the
heating effects of electricity in conductors and
junctions.
electrotitration In chemistry, the completion of
titration, as indicated by an electrical measurement,
such as of the resistance of the solution being
titrated.
electrotonic Pertaining to ELECTROTONUS.
electrotonus Modification of a nerve’s sensitivity
by passing a constant current through it.
electro-ultrafiltration In physical chemistry, filtering
a colloidal suspension by electro-osmosis.
electrovalence 1. The number of charges acquired
by an atom gaining electrons. 2. The number of
charges forfeited by an atom losing electrons. 3.
Valence resulting from electron transfer between
atoms and the resulting creation of ions.
electrovalency See ELECTROVALENCE.
electrovalent bond See IONIC BOND.
electrowin To recover (win) a metal from a solution
of its salts by means of electrolysis.
electrum A natural alloy of gold and silver.
element 1. See ELECTRODE. 2. A circuit component
intended for a specific purpose. 3. A specific
part of an antenna array (e.g., driven
element or parasitic element). 4. A fundamental,
unique substance whose atoms are of only one
kind (examples: aluminum, carbon, silicon, and
sulfur). There are more than 100 elements, some
man-made. Elements combine to form compounds.
5. A circuit, such as an AND gate, that
can be taken as a unit because it performs
a special function. 6. In digital computer