Glossary
G-2 Getting Started Guide
Glossary
Abbé error—The measurement error resulting from angular motion of a
moveable component and the Abbé offset between the scales measuring
the motion of that component and the measurement line.
Abbé offset—The perpendicular distance between the displacement
measurement axis of a machine (the machine’s scales) and the
measurement line where displacement in that coordinate is being
measured accuracy—How closely a measurement agrees to a known
standard or true value. See the industrial standard you are using for a
precise definition of accuracy.
ambient—Surrounding on all sides. For example, ambient temperature
refers to the temperature of the machine’s environment.
AMT—Association of Manufacturing Technology.
ANSI—American National Standards Institute.
arcsec, arcseconds—1/3,600 of one degree of arc, equivalent to
approximately 4.85 micro units per unit.
ASME—American Society of Mechanical Engineers.
azimuth—1) The lateral deviation of the laser beam from the machine
travel path. 2) The horizontal angular distance from a fixed reference
direction (laser beam travel) to a position, object, or object referent.
BSI—British Standards Institute.
CMM—Coordinate Measurement Machine.
coefficient of thermal expansion (CE)—The amount by which a
material expands or contracts due to a change in temperature. Usually
expressed in parts per million (ppm) per degree of temperature change
(either Celsius or Fahrenheit).