A spring designed so that its torque cancels that of the instrument of which it is a part, for all deflections of the pointer.
Related Terms |
PLUNGER-TYPE INSTRUMENT
Moving-iron instrument in which the pointer is attached to a long and specially shaped piece of iron that is drawn into or moved out of a coil carrying the current to be measured.
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PITOT TUBE
An instrument that measures the stagnation pressure of a flowing fluid, consisting of an open tube pointing into the fluid and connected to a pressure-indicating device. Also known as impact tube.
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PIEZOMETER
1. An instrument for measuring fluid pressure, such as a gage attached to a pipe containing a gas or liquid. 2. An instrument for measuring the compressibility of materials, such as a vessel that determines the change in volume of a substance in response to hydrostatic pressure.
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PHOTOCLINOMETER
A directional surveying light is directed through the material, and the instrument which records photographically the amount of light transmitted is measured with waves from the discharge.
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PHONOGRAPH
[ENG ACOUS] An instrument for recording or reproducing acoustical signals, such as voice or music, by transmission of vibrations from or to a stylus that is in contact with a groove in a rotating disk.
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PENETROMETER
1. An instrument that measures the penetrating power of a beam of xrays or other penetrating radiation. 2. An instrument used to determine the consistency of a material by measurement of the depth to which a standard needle penetrates into it under standard conditions.
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PENDULUM LEVEL
A leveling instrument in which the line of sight is automatically kept horizontal by a built-in pendulum device (such as a horizontal arm and a plumb line at right angles to the arm).
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PEDOMETER
1. An instrument for measuring and weighing a newborn child. 2. An instrument that registers the number of footsteps and distance covered in walking.
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PANTOMETER
An instrument that measures all the angles necessary for determining distances and elevations.
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PACHYMETER
An instrument used to measure the thickness of a material, for example, a sheet of paper.
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