Controlling systematic errors in rock testing by measurement uncertainty analysis

Abstract

In engineering and fundamental sciences, many important decisions are based on the results of quantitative measurements. When an observation result is stated, it is also required to determine the uncertainty associated with the observation. A measurement uncertainty analysis comprises of random and systematic components. Different from the random fluctuations, systematic uncertainties are resourced from the specifications, environmental conditions, calibration and other heuristic critical factors. This study assesses the systematic and random effects which create some uncertainty on a Schmidt Hammer (SH) rebound hardness test. In particular, as the certain probability terms, the systematic uncertainty component is focused and its volume has been appraised from a control framework. The importance of elemental uncertainty and coverage term are discussed from a statistical control perspective. In the same ground, the effective number of degrees of freedom is also evaluated. In this way, the importance of the fixed error sources has been appraised based on statistical control perspective. The use of an uncertainty term as a measurement parameter in testing-based decision making can provide some reliable and realistic information for engineering risk management and quality control.

Robust Analysis of Various Measurement Uncertainty Parameters in Rebound Hammer Test

“…On a standard scale, the rebound value is expressed as a rebound index. The hammer's body features a graph from which the compressive strength can be easily determined (3,(10)(11)(12) . In case of rebound hammer test researchers can only apply regression equations that they have obtained from the results of laboratory tests within the parameters that have been set for that particular implementation.…”

“…The type A standard uncertainty (U r ), arising from repeated measurements on the concrete block is determined by equation (1) (3) , (9,10) .…”