An accredited calibration laboratory is one whose competence in certain fields of calibration has been officially approved by an accreditation body conforming to relevant laws or international standards through assessment of its management systems and technical competency by assessors qualified under the relevant standard (KS Q ISO/IEC 17025).

Overview
A KOLAS accredited calibration laboratory is one whose competence in certain fields of calibration has been officially approved by an accreditation body conforming to relevant laws or international standards through assessment of its management systems and technical competency by assessors qualified under the relevant standard (KS Q ISO/IEC 17025).

In order to maintain the precision and accuracy of measuring equipment, periodic calibrations with reference instruments having higher levels of precision and accuracy are carried out and therefore, traceability with national calibration standards can be maintained. As a result, measurement errors that can occur from the continuous use, abrasion, expiration of service life, or any changes in usage condition, remain within permitted tolerances.
The ultimate goal of the calibration scheme is to secure the homogeneity and performance of products during manufacturing processes, and earn external credibility regarding measurement results produced by testing and research laboratories.

Background of Introducing the Calibration Scheme
Internal Reasons
-Improving calibration capability of accredited calibration laboratories and securing high quality personnel -Meeting the increasing demand for the credibility of calibration certificates issued by accredited calibration laboratories at home

External Reasons
-Eliminating TBT (Technical Barriers to Trade) by resolving discrepancy in applicable standards and schemes through harmonization, and introducing conformity assessment schemes that satisfy international practices and standards -Maintaining metrological traceability with internationally agreed standards (SI units) for fair trade, and meeting a strong demand for the credibility of measurement results

As developed countries are gradually increasing TBT through measures protecting their domestic industries, customers, safety and environment, KOLAS aims to gain full mutual recognition by advancing its accreditation scheme for calibration laboratories to meet all relevant international standards.


Benefits from obtaining accreditation as calibration laboratories in accordance with international standards
-Lending international credibility to calibration results of accredited calibration laboratories
-Securing credibility of calibration certificates with expression of uncertainties
-Enhancing credibility of measurement results and calibration capabilities by periodically participating in proficiency tests including interlaboratory comparisons at home and overseas
-Reducing export costs by eliminating duplicate inspection through the mutual recognition among countries and regions

If your organization is preparing to apply for KOLAS calibration laboratory accreditation, please download the latest accreditation criteria including KOLAS Regulations on the Accreditation of Calibration Laboratories from the website, and inquire to the KOLAS Secretariat about relevant procedures and requirements.
(☏ 043-870-5498,5476 kolasc@korea.kr)


Applicable Documents and Laws
Laws related to the National Calibration Scheme
-Framework Act on National Standards
-Enforcement Decree of the Framework Act on National Standards

Domestic and International Accreditation Criteria applied to the Scheme
-KS Q ISO/IEC 17011 (ISO/IEC 17011): Conformity Assessment—Requirements for Accreditation Bodies accrediting Conformity Assessment Bodies

Accreditation Criteria for accredited Calibration Laboratories
- KOLAS Regulations on the Accreditation of Calibration Laboratories
- KS Q ISO/IEC 17025 (ISO/IEC 17025): General Requirements for the Competence of Testing and Calibration Laboratories
- KOLAS Guidance on the Accreditation of Testing and Calibration Laboratories (KS Q ISO/IEC 17025 Interpretation Guide)
- Supplementary Requirements for On-site Calibration
- Guidance on Traceability of Measurement Results
- KOLAS Regulations on the Accreditation and Assessment of Conformity Assessment Bodies (CABs)
- Guidance on the Use of Accreditation Marks and Claims for Accredited Status
- Guidance on Calculating, Maintaining and Managing Calibration and Measurement Capability (CMC)
- Guidance on Calibration of Instruments and Calibration Intervals
- Regulations on Proficiency Testing Schemes
- ILAC Guidelines


Calibration Subjects and Calibration Intervals
Calibration Subjects


What are the Calibration Subjects?
Article 40 of the KOLAS Regulations on the Accreditation of Calibration Laboratories stipulates that “In order to enhance traceability of measuring instruments used universally in all fields in society and to follow standards defined in Article 14 of the Framework Act on National Standards, those who keep or use the measurement instruments are required to have the instrument calibrated periodically and may set and manage the calibration subjects and scopes of application on their own.”

Calibration is required in industrial sites because testing and calibration should be carried out with accurate measuring instruments. The accuracy can be verified based on the permitted tolerances required in specifications. Such inspections on accuracy are conducted through periodic comparisons and calibrations using higher reference instruments. Therefore, subjects to be calibrated shall be set based on the concept of credibility to ensure their performances can be maintained within the permitted tolerances.

In some cases, however, calibration is not required due to the performances or structures of measuring instrument; and in some fields, there are no relevant national standards for measurement or adequate calibration methods (e.g. fields such as surface characteristics and non-destructive testing), which makes calibration practically impossible


Download Calibration Interval Setting
Article 40, Paragraph 2 of KOLAS Regulations on the Accreditation of Calibration Laboratories stipulates that “If those who keep or use measuring instrument wish to set the calibration intervals on their own, they are required to set in a scientific and reasonable manner by considering the precision, stability, purpose, environment, and frequency of use of the measuring instrument.” “However, an inability to set calibration intervals in a scientific and reasonable manner on their own entitles them to apply calibration intervals that the Head of KOLAS has set and issued a public notice about.”

However, the calibration intervals stipulated in Guidance on Calibration of Instruments and Calibration Intervals are estimated periods, which are assumed to be able to maintain the precision and accuracy of measuring instruments under the most common environments. Although the calibration intervals are set for the 568 measuring instruments in 42 ‘Groups’ of accreditation fields, it is recommended to each business that uses or owns measuring instruments to adjust the intervals in consideration of its accuracy, stability, purpose, environment and frequency of usage.

The recommendation means setting uniform calibration intervals is unreasonable, because even when they are located within the same workplace, the working environments, range of measurement and permitted margins of error may vary in each department; thus it is desirable to set adequate calibration intervals after analyzing accumulated date on the usage of instruments and on measured values collected from each department. Therefore, it is a prerequisite to secure accumulated measurement data to be used as the basis for adjusting calibration intervals.