The generic term for a well log that displays electrical measurements of
induced current flow (resistivity log, induction log) or natural
potentials (spontaneous-potential curve) in the rocks of an uncased
borehole. An electric log typically consists of the spontaneous-potential
curve and one or more resistivity or induction curves. The Archie
equations form the basis for interpretation of electric logs. Abbrev:
E-log. Informal syn: resistivity log. See also:borehole log;
well logging. AGI
a. A technique in which electrical measurements are made, and recorded at
the surface, while a series of electrodes or coils is caused to traverse a
borehole. The resulting curves can be used for geological correlation,
and, under favorable circumstances, for the recognition of some rock
properties and for indicating the nature and amount of the fluids in the
pores of the rock. Inst. Petrol.
b. The act or process of taking resistivity, porosity, electrical
anisotropy, etc., measurements in a borehole using an electromagnetic
teleclinometer or other electrode device. Also called electrical logging.
See also:self-potential log
An electric locomotive designed for use underground.
See also:locomotive; mine locomotive; electric haulage mine locomotive;
electric permissible mine locomotive; electric gathering mine locomotive.
Electric motor. Korson
electric permissible mine locomotive
An electric locomotive carrying the official approval plate of the U.S.
Mine Safety and Health Administration.
These fuses were designed so that electrical shotfiring methods could be
used for initiating blasting powder. The powder fuse consists of a thick
paper tube containing a small charge of blasting powder, with an ordinary
low-tension fusehead fixed at one end. On passing electric current through
the fusehead, it flashes and sets off the blasting powder in the tube,
which can then initiate the main charge of blasting powder in the shot
hole. McAdam, 2
A method of collecting particulate particles used chiefly in air polution
control that consists of inducing an electric charge on the dust particles
and collecting them on an oppositely charged device.
electric prospecting instruments
Geophysical prospecting instruments that measure the electrical
characteristics of rocks. Nelson
The opposition of an electric circuit to the flow of current.
Kentucky
electric resistance strain gage
This gage consists essentially of a grid of fine wire cemented to a paper
membrane, which can be attached to the surface under investigation. The
ends of the wire grid are spot welded to a metal strip for the terminal
connections. The use of these gages depends upon the fact that certain
alloys show a linear relationship between applied strain and electrical
resistance, so that if a wire constructed from one of these alloys is
fixed to the surface of an object subject to variable strain, the change
of resistance in the wire will be a measure of the change of strain in the
object. Issacson
A hand-held rotary drill driven by an electric motor, which may be used in
rock or coal. It may be of fan-cooled design with several rod speeds to
suit different rocks. The use of aluminum or aluminum alloys is not
favored where methane is liable to be present. This drill produces
considerably less dust than the percussive drill. Nelson
Paralysis of the nerve center that controls breathing or a regular
heartbeat. Some symptoms of electric shock are sudden loss of
consciousness, absence of respiration or respiration that cannot be
detected, weak pulse, and burns. Kentucky
Most of the larger modern machines are electrically driven and are
equipped with the Ward-Leonard system of control, which allows alternating
current of fairly high voltage to be carried to the shovel over a very
flexible electric cable. This cable is usually carried on a sled back of
the shovel or on a reel on the shovel base. The current drives an
alternating current motor, which is connected to, and drives, direct
current generators, one for each of the operations of the shovel, and an
exciter. Each direct current generator and the direct current motor which
it drives are in a closed circuit. The field in each circuit is regulated
by magnetic contactors or by rotating controls actuated by master
controllers at the operator's position.
See:shovel craneman
In bituminous coal mining, one who operates a hoist powered by electricity
to haul loaded and empty cars along a haulage slope to surface of mine.
DOT
An electric centrifugal pump consisting of a small vertical centrifugal
pump so designed that it will draw water if it is only 2 to 3 in (5.1 to
7.6 cm) deep. It is placed in the water at the bottom of a shaft and lifts
the water up to a horizontal centrifugal pump placed about 50 ft (15.2 m)
above. Lewis
A small shell containing an explosive compound that is ignited by the
electric current brought in through the lead wires. Used for firing single
small holes loaded with black powder. Lewis
Steel made in an electric furnace. Mersereau, 2
The haulage of vehicles by electric power, derived from overhead wires,
third rail, storage batteries, or diesel-driven generators mounted on the
vehicles. Hammond
A wheel containing the motor and all the required gearing so that it is an
independent drive unit. Woodruff