TEQ / KNOWLEDGE CENTER
Practical guidance on calibration, measurement uncertainty, traceability and laboratory quality, published by TEQ. The articles help quality managers, laboratory staff and engineers assess measuring equipment, read calibration certificates and prepare useful service enquiries. Authorship is identified on each article; educational content does not replace confirmation of the current accredited scope.
THE LIBRARY
20 articles · English edition
Calibration Basics
What calibration actually is, what it is not, why instruments drift, and what an out-of-tolerance result costs. Practical guidance from an accredited lab.
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The difference between calibration, verification, adjustment and intermediate checks, with a balance example and a quick comparison table.
There is no universal calibration interval. How to set one from drift history and risk, the ILAC-G24 methods, and the events that call for calibration early.
Which instruments need accredited calibration, which can be calibrated in-house, and which need no calibration at all. A practical approach for quality managers.
Why resolution is not accuracy, why the 10:1 rule is not a law, and why calibration labels should not carry the lab’s due date. Three common errors explained.
The prevention–appraisal–failure model, cost of poor quality and the 1-10-100 rule, with worked examples showing how small calibration errors become large losses.
What traceability really requires, why uncertainty is part of it, and how to check a calibration certificate’s traceability claim. A practical guide.
What measurement uncertainty is, how it differs from error, the GUM method step by step, a worked pressure gauge budget, and how to use uncertainty in decisions.
How decision rules work under ISO/IEC 17025 and ILAC-G8: simple acceptance, guard bands, binary and non-binary statements, with a worked example.
What an ISO/IEC 17025 calibration certificate must contain, a clause-by-clause checklist, a five-minute review method and the red flags to watch for.
ILAC and IAF have become Global ACI. What the new Global ACI MRA means for accredited calibration certificates, the ILAC MRA mark, and supplier approval.
ISO 9001:2026 is published. What changed from ISO 9001:2015, clause by clause, the confirmed transition dates to September 2029, and a step-by-step transition plan.
Metrology is the science of measurement. Its three branches explained with examples, how they connect through traceability, and why calibration is not legal verification.
How ancient Egypt measured length, mass and volume, how long the royal cubit was, and why its system of master and working cubits still describes calibration today.
How the metric system began, how the SI grew to seven base units, and what the 2019 redefinition based on fundamental constants means for calibration.
Prepare a pressure or vacuum gauge calibration enquiry with the pressure reference, units, working range, connections and reporting requirements.
Prepare a balance calibration request covering capacity, resolution, actual working loads, installation, previous results and acceptance requirements.
Distinguish a thermometer calibration enquiry from a chamber temperature study and identify the sensor, working volume, loading and reporting questions.
Prepare a volume calibration enquiry covering instrument type, capacity, volume settings, delivery or containment markings, accessories and previous use.
Define an electrical calibration request with required functions, ranges, frequencies, oscilloscope channels, probes, specifications and reporting needs.
