Distributions for Uncertainty Estimation using the ISO Guide to the Expression of Uncertainty in Measurement.

Type	Normal	Triangular	Rectangular	U-shaped	Step
Graphical Representation
Equivalent Standard Deviation
Use	When type A-evaluations can be shown to follow this distribution.	When 'hard' limits can be estimated easier than sigma,e.g.: Noise Vibration	When only the variation limits are known, e.g.: Calibration Certificates Manufacturer's Specifications	For cyclic influences, e.g.: Temperature Variation	When resolution is limited, e.g.: Digital Readout Verniers Scale read by Operator

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