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Related to Dial calipers: inside caliper, Digital calipers, Dial callipers


(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



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.



(design engineering)
An instrument with two legs or jaws that can be adjusted for measuring linear dimensions, thickness, or diameter.


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.
References in periodicals archive ?
To find out how well your scope measures up, cast an eye on a power pole when the Sun shines, borrow a dial caliper, and go have some fun.
Dial calipers add a dial readout affixed to the movable jaw assembly, and are the most common caliper model in use.
Among the many variations of dial indicators: long-range indicators for measuring table movement or slide travel, dial calipers for quick ID comparisons, pocket thickness gages for quick checks of materials, dial snap gages for ODs up to 12", dial bore gages for three-point contact go/no-go measurements, and back plungers where the mounting stem is on the back for mounting on holding fixtures.
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Tenders are invited for Set Of Vernier Dial Calipers Of Range 0-300Mm And 0-600Mm,One Number Each As A Set,Make:Mitutoyo Or Aerospade Along With Calibration Certificate.
A dial caliper was used to take the inter-recti distance pre and post administration of exercise.