Metrological Traceability
Definition
A property of a measurement result whereby the result can be related to a reference (ultimately the SI system of units) through a documented, unbroken chain of calibrations, each contributing a stated uncertainty; the foundation of the CRM chain and of all quantitative forensic chemistry results.
Related terms
- Certified Reference Material (CRM)
- A sample with one or more analyte concentrations established by an accredited body and traceable to a national metrology institute. NIST SRM...
- Internal Standard (IS)
- A compound chemically near-identical to the analyte, often a deuterated isotopologue (d3-morphine, d5-EDDP, d5-alprazolam, pyrene-d10), spiked into every sample at a known...
- ISO 17034
- The international standard specifying general requirements for the competence of reference material producers; an ISO 17034-accredited producer has demonstrated the technical competence...
- Limit of Detection (LOD)
- The lowest concentration of analyte that produces a signal reliably distinguishable from the instrument noise, conventionally three times the standard deviation of...
- Limit of Quantification (LOQ)
- The smallest concentration that can be quantified with acceptable precision and accuracy, typically corresponding to a signal-to-noise ratio of 10:1 or an...
- Linearity
- The range of analyte concentrations over which an analytical method produces instrument responses that are proportional to concentration (the calibration curve is...
- Measurement Uncertainty (MU)
- A quantified parameter associated with a result that characterises the dispersion of values reasonably attributable to the measurand. Estimated by the GUM...
- NIST SRM (Standard Reference Material)
- A reference material issued by the US National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, whose property values are established...
- System Suitability Test
- A pre-run check in which a standard mixture is injected into the analytical instrument and key parameters (retention times, peak widths, signal-to-noise...
Explained in
- Reference Standards, Certified Reference Materials and the Quantification BaselineA property of a measurement result whereby the result can be related to a reference (ultimately the SI system of units) through a documented, unbroken chain of...