An instrument consisting of a protractor and one or more arms attached to a parallel motion device, so that the movement of the arms is everywhere parallel. The protractor can be rotated and set at any position so that it can be oriented to a chart. Also called DRAFTING MACHINE.

Related Terms


An instrument for measuring the magnitude of electric current flow.


A device which converts mechanical force and motion into pneumatic flow power.


A sliding type of bearing having either rotating or oscillatory motion and in conjunction with which a journal operates. In a full or sleeve type journal bearing, the bearing surface is 360° in extent. In a partial bearing, the bearing surface is less than 360° in extent, i.e., 150°, 120°, etc.


An instrument for determining either the specific gravity of a liquid or the API gravity.


The projection of circular motion on a diameter of the circle of such motion. Simple harmonic motion is produced if the circular motion is of constant speed. The combination of two or more simple harmonic motions results in compound harmonic motion.


Fluctuation about a mid-point due to instability, as oscillations of the needle of an instrument about the zero point.


Cushioning material placed among cargo to prevent their motion


An instrument for measuring the velocity of a fluid.


A system of lubrication in which the shape and relative motion of the sliding surfaces causes the formation of a fluid film having sufficient pressure to separate the surfaces.


An instrument or device for measuring, indicating or comparing a physical characteristic.

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