IEEE 836-2001 pdf download IEEE Recommended Practice for Precision Centrifuge Testing of Linear Accelerometers
3. Definitions, symbols, and acronyms
For the purposes of this recommended practice, the following terms and definitions apply. IEEE 100The Authoritative Dictionary ofIEEE Standards Terms, Seventh Edition B6J” should be referenced forterms not defined in this clause.
3.1 Definitions relevant to centrifuge testing
3.1.1 arm stretch (ARas): Elongation, due to centrifugal loading, of the mechanical structureconnecting an accelerometer to the centrifuge spin axis beyond the static value (Ro).
3.1.2 bucking: An unusually strong interaction between certain terms in a nonorthogonal series due toa similarity in the functions that they represent.
3.1.3 Central Limit Theorem: A theorem that states that under general conditions the probabilitydistribution of the sum of n statistically independent random variables (or their average) approachesthe Gaussian (or normal) distribution as n approaches infnity, no matter what the individualdistribution functions might be. In-so-far as the total crror in a measurement or in the average of anumber of measurements is the sum of a number of small independent errors. total measurement errortends to be Gaussian, unless dominated by a single source of error such as quantization noise. Syn.Normal Convergence Theorem.
3.1.4 centrifuge: A device consisting of a motor- or engine-driven arm structure of suflicient dimensionsand strength to allow the rigid mounting and subjecting of one or more inertal grade accelerometersto centripetal acceleration levels ranging from fractions of 1 g to over 200 g.
3.1.5 centrifuge arm axis: A line perpendicular to the axis of rotation of a centrifuge through theeffective center of mass of the accelerometer under test.
3.1.6 coning: Precession of a centrifuge due to imbalance.
3.1.7 dynamic error: An error that is present when a centrifuge is rotating.
3.1.8 dynamic leveling error: Any angular deflection of the accelerometer mounting fixture from ahorizontal line perpendicular to the centrifuge centripetal acceleration vector.
3.1.9 gravity (gl). See: plumb-bob gravity.
3.1.10 Normal Convergence Theorem. See: Central Limit Theorem.
3.1.11 plumb-bob gravity: The force per unit mass acting on a mass at rest at a point on the earth, notincluding any reaction force from the suspension. The plumb-bob gravity includes the gravitationaattraction of the Earth, the eflect of the centripetal acceleration due to the earth rotation. and tidaleffects. The direction of the plumb-bob gravity acceleration defines the local vertical down direction.and its magnitude defines the unit of acceleration g used in accelerometer scale factor calibration at atest site (with compensation for tidal effects if accuracy warrants).
3.1.12 radial stiffness: A direct measure of the resistance of the centrifuge axis to deflection due to ahorizontal force at the center of rotation: it must take into account the effects of all compliances of thestructure, including the bearings, connection to the floor, and the foundation upon which the machineis mounted.
3.113 static error: An error that is present when a centrifuge is not rotating: it may change with armposition.
3.1.14 static leveling error: An error in the acceleration seen by a test item due to misalignments of theaccelerometer input axis to the centrifuge and gravity vector.
IEEE 836-2001 pdf download
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