GSAB – Global Standard Accreditation Board provides independent and impartial accreditation to Dimensional Metrology (Length) Calibration Laboratories in accordance with ISO/IEC 17025.
Our accreditation process ensures laboratories demonstrate technical competence in length and dimensional measurement calibration, validated calibration methods, reliable measurement results, and internationally traceable standards to the SI unit of length (metre).
What Do Dimensional Metrology (Length) Calibration Laboratories Do?
Dimensional metrology laboratories calibrate and verify instruments used to measure length, distance, diameter, thickness, flatness, roundness, and geometric parameters. They ensure:
-Accuracy and correction factors of measuring instruments
-Dimensional conformity to specified tolerances
-Measurement repeatability and reproducibility
-Geometric parameter verification
-Measurement uncertainty estimation
-Traceability to national or international length standards
These laboratories play a critical role in precision manufacturing, quality assurance, and regulatory compliance.
Industries supported include:
-Automotive Manufacturing
-Aerospace & Defense
-Precision Engineering
-Tool & Die Manufacturing
-Construction & Infrastructure
-Heavy Machinery & Fabrication
-Electronics & Semiconductor Manufacturing
Typical Dimensional Metrology (Length) Calibration Services Performed
Depending on their scope, laboratories may conduct:
-Vernier caliper calibration
-Micrometer (inside, outside, depth) calibration
-Dial gauge and digital indicator calibration
-Height gauge calibration
-Bore gauge calibration
-Slip gauge (gauge block) calibration
-Measuring tape and steel rule calibration
-Plug gauge and ring gauge calibration
-Thread gauge calibration
-Surface plate flatness measurement
-Coordinate Measuring Machine (CMM) verification
-Optical comparator calibration
-Laser interferometer-based length calibration
-Profile projector verification
GSAB verifies that all calibration methods are technically validated, environmental conditions (temperature, humidity, vibration) are strictly controlled, measurement uncertainty is properly calculated, and traceability to primary length standards is established.
Who Can Apply?
Dimensional metrology (length) accreditation is suitable for:
-Independent calibration laboratories
-In-house industrial calibration facilities
-Aerospace and automotive quality laboratories
-Tool room and precision engineering units
-Government metrology laboratories
-Research and testing institutions
-Contract calibration service providers
Accreditation Criteria
GSAB accredits dimensional metrology laboratories based on:
-ISO/IEC 17025
-Applicable ILAC mandatory documents
-National and international metrology requirements
-Industry-specific technical standards (where applicable)
Accreditation confirms:
-Technical competence of calibration personnel
-Validated dimensional calibration procedures
-Proper reference standards (gauge blocks, interferometers, master gauges)
-Environmental monitoring and control
-Measurement uncertainty evaluation
-Traceability to SI unit of length (metre)
-Equipment maintenance and intermediate checks
-Risk-based management system implementation
GSAB operates in accordance with ISO/IEC 17011, ensuring impartiality, technical rigor, and integrity in accreditation decisions.
GSAB follows a structured and technically rigorous accreditation process:
1. Application & Scope Definition
The laboratory submits a defined calibration scope including dimensional parameters, measurement ranges, and declared Calibration and Measurement Capabilities (CMC).
2. Document Review
Evaluation of:
-Quality Manual
-Dimensional calibration procedures
-Uncertainty budgets
-Traceability documentation
-Environmental monitoring records
-Proficiency testing or inter-laboratory comparison participation
-Internal audit and management review records
3. On-Site Assessment
-Evaluation of laboratory environmental controls (typically 20°C reference condition)
-Verification of reference standards and master gauges
-Witnessing of live calibration activities
-Assessment of personnel competence
-Review of equipment maintenance and intermediate verification
4. Corrective Actions & Technical Review
-Review of nonconformities
-Verification of corrective actions
-Independent technical review prior to accreditation decision