(redirected from calipers)
Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to calipers: brake calipers, Digital calipers


(US), caliper
1. an instrument for measuring internal or external dimensions, consisting of two steel legs hinged together
2. Med a splint consisting of two metal rods with straps attached, for supporting or exerting tension on the leg
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a device that is lowered into a bore hole on a cable to determine the diameter of the hole. Mechanical and ultrasonic calipers are used.

The most commonly used mechanical caliper consists of three or four lever feelers (probes), which are pressed against the walls of the bore hole by springs, and a rheostat whose sliding contact is connected to the feelers by means of pushrods. A change in the diameter of the borehole produces a proportional change in the resistance of the rheostat. This resistance is measured on the surface and, as a result, a curve is produced showing the change in the diameter of the borehole from the face to the mouth of the hole. Recent models are equipped with a controlled lever device that can be opened and closed repeatedly on command from the surface.

An ultrasonic caliper is a hydrolocating device with two directional electroacoustic transducers located on opposite sides of the borehole instrument. Each transducer operates alternately as an ultrasonic oscillation emitter and detector. The time interval between the moments of the transducer’s emission and its reception of the ultrasonic pulse reflected from the wall of the borehole is measured on the surface. Since the interval is proportional to the distance from the device to the borehole wall, two longitudinal profiles of the borehole are produced, characterizing its diameter.

Since the cross section of a borehole is usually noncircular, instruments have been developed that permit measurement of the size and shape of the cross section.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


(design engineering)
An instrument with two legs or jaws that can be adjusted for measuring linear dimensions, thickness, or diameter.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


An instrument, resembling a pair of dividers, with adjustable legs for measuring the diameter or the thickness of bodies. Also see inside caliper and outside caliper.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
Get the Market Alerts: The section -- automotive brake caliper market analysis, by product type comprehensively analyzes the market on the basis of products type where automotive brake caliper is used.
Global Brake Caliper Market is predicted to grow significantly in the coming years owing to the mandatory use of brake caliper in vehicles and increase in demand for automobiles worldwide.
Wheel-end suspensions include wheels, brake calipers, brake discs, steering knuckles and suspension arms and links.
With a digital caliper (recommended), you first zero the caliper with the attachment installed and closed.
"AP Racing will always act to protect its intellectual property rights around the world, in order to safeguard our research and development work going forward.' Offering less mass, improved rigidity and better cooling characteristics than conventional brake caliper designs, the Radi-CAL concept represented a major innovation in braking technology when it was introduced.
All caliper measurements were taken using model Y3110337 digital calipers (Fischer Scientific, Pittsburgh, Pennsylvania, USA); therefore, times required to collect measurements are considered minimum estimates, as traditional non-digital dial calipers do not provide readable displays and their use would require additional time to determine measurements.
To prolong battery life, the 0 to 6", 8", and 12" calipers automatically shut off after 5min of inactivity, while retaining the last measuring position.
Carlisle Industrial Brake and Friction, Bloomington, Ind., has introduced a hydraulically actuated, single opposed piston, caliper disc brake for use in a variety of applications such as underground shuttle vehicles, log skidders and other industrial equipment.
Dimension quality inspection of rotationally symmetric rubber seals is typically manually inspected with the use of technical tools such as dimension calipers and ring gauges.
MEASURING UP: Quality engineer Ian Penny measuring brake calipers for the new VW Touran (left) and the Golf (right) at Ebbw Vale-based Continental Teves, which has won a multi-millionpound contract to supply 600,000 calipers a year for the Touran mini MPV which will be going on sale next summer.
Calipers and friction materials are the cornerstone of automotive braking systems -- and of Akebono Brake Industry Co.'s business.