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Angular distance from the zenith; the arc of a vertical circle between the zenith and a point on the celestial sphere, measured from the zenith through 90°, for bodies above the horizon. This is the same as COALTITUDE with reference to the celestial horizon.
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Related Terms |
POINT-BLANK RANGE
Distance to a target that is so short that the trajectory of a bullet or projectile is practically a straight, rather than a curved, line.
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PISTON DISPLACEMENT
The volume which a piston in a cylinder displaces in a single stroke, equal to the distance the piston travels times the internal cross section of the cylinder.
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PHOTOFLASH BOMB
A missile dropped from aircraft; it contains a photoflash mixture and a means for ignition at a distance above the ground, to produce a brilliant light of short photoelectric effect See photoelectricity.
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PHONOTELEMETER
A device consisting essentially of a stopwatch, for estimating the distance of guns in action by measuring the interval between the flash and the arrival of the sound.
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PENETRATION NUMBER
The consistency of greases, waxes, petrolatum, and asphalt or other bituminous materials expressed as the distance that a standard needle penetrates the sample under specified American Society for Testing and Materials test.
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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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PASSIVE RADAR
A technique for detecting objects at a distance by picking up the microwave electromagnetic energy that is both radiated and reflected by all bodies.
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PARSHALL FLUME
A calibrated device for measuring the flow of liquids in open conduits by measuring the upper and lower beads at a specified distance from an obstructing sill.
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OROGRAPH
A machine that records both distance and elevations as it is pushed across land surfaces; used in making topographic maps.
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ODOMETER
1. An instrument for measuring distance traversed, as of a vehicle. 2. The indicating gage of such an instrument. 3. A wheel pulled by surveyors to measure distance traveled.
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