A
product or service should be 'Fit for purpose', conforming to specified
requirements with respect to National standard / International standard /
User's specification. This requires the services of a calibration
laboratory, which should be accredited. 'Accreditation is a process of
formal recognition of technical competence in accordance with the prevailing international standard' by a recognized accreditation institution.
The National Accreditation Board for testing and calibration Laboratories (NABL) is a full member of Asia Pacific Laboratory Accreditation Co-operation (APLAC) and International Laboratory Accreditation Co-operation (ILAC). Because of a comprehensive requirement of combining inspection and testing in many areas, NABL provides accreditation for inspection bodies in accordance with ISO/IEC 17020 International standard, and ISO/IEC 17025:1999.
A Calibration laboratory shall be accredited according to their 'Best measurement capability'. It means the least uncertainity of measurement (±) at a confidence probability level of 95%. The calibration laboratory is not permitted to report a smaller uncertainity of measurement than the best measurement capability on its endorsed documents. Obviously, the actual uncertainty of measurement can never be smaller than the best measurement capability.
The calibration laboratory shall be organized in such a way as to ensure the integrity and training of its staff and operations for ensuring unbiased calibration. There should be an authorized signatory for the calibration certificates/reports issued by the laboratory. It should have a quality manual, which should be maintained up-to-date and available for scrutiny, in compliance with ISO/IEC 17025 and NABL requirements. The quality manual should contain a quality policy statement, objectives, commitments by the top management, names, qualifications, experience of persons responsible for the managerial, scientific/technical activities, measurement capability, Traceability of calibration of all measuring instruments to standard, calibration procedures adopted, National/International standards referred/used.
The laboratories should have authorized signatories for approving and issuing calibration certificates for each calibration parameter as mentioned in the scope of accreditation. The laboratory should have an adequate number of qualified and trained staff with at least a degree in Physics or Diploma in Engineering. The team should be headed by a P.G. in Physics or Graduate in Mechanical/Instrumentation Engineering.
The calibration area shall be adequately free from vibrations generated by air-conditioning plant, vehicular traffic or any other such sources. Acoustic noise level shall be maintained for proper performance of calibration. A threshold noise level of 60 dBA is to be maintained as recommended. Adequate level of illumination has to be maintained, fluorescent lighting is preferred to avoid localized heating and temperature drift. The recommended level of illumination is 450-700 lux on the working table with glare index of 19 for the laboratory.
The environmental conditions for the activity of the laboratory shall be such as not to adversely affect the required accuracy of measurements. As possible, only the staff engaged in calibration activity should be permitted entry inside the calibration area. Laboratory should have equipment of required accuracy in respect of each parameter covered. Stability of the standards, accuracy of the values realized through them and repeatability, should be regularly monitored.
Calibration certificates, performance history sheets, working standard details should be held safely by the laboratory. Each equipment should have a record of name, manufacturers name and address, type, range, identification and serial no., date of procurement and commissioning, details of calibration, details of maintenance, performance history with dates. The service manual has to be available at all times.
All the standard equipment of the laboratory should be calibrated periodically against calibration standards of a laboratory accreditated by NABL/ equivalent MRA partners having superior measurement capability or NPL/ other international NMIs. To give further assurance to the accuracy or uncertainty of measurements, a laboratory should be required to participate from time to time, in Proficiency Testing Programmes. There the abnormalities of equipment are detected in terms of En number, through inter-comparisons and the appropriate corrective actions should be taken. The standard equipment shall be replaced/ repaired and re-calibrated with a higher accuracy standard. Reports on such inter-comparisons should be documented with reference. This Proficiency Testing practice should be included in the Quality Manual.
The National Accreditation Board for testing and calibration Laboratories (NABL) is a full member of Asia Pacific Laboratory Accreditation Co-operation (APLAC) and International Laboratory Accreditation Co-operation (ILAC). Because of a comprehensive requirement of combining inspection and testing in many areas, NABL provides accreditation for inspection bodies in accordance with ISO/IEC 17020 International standard, and ISO/IEC 17025:1999.
A Calibration laboratory shall be accredited according to their 'Best measurement capability'. It means the least uncertainity of measurement (±) at a confidence probability level of 95%. The calibration laboratory is not permitted to report a smaller uncertainity of measurement than the best measurement capability on its endorsed documents. Obviously, the actual uncertainty of measurement can never be smaller than the best measurement capability.
The calibration laboratory shall be organized in such a way as to ensure the integrity and training of its staff and operations for ensuring unbiased calibration. There should be an authorized signatory for the calibration certificates/reports issued by the laboratory. It should have a quality manual, which should be maintained up-to-date and available for scrutiny, in compliance with ISO/IEC 17025 and NABL requirements. The quality manual should contain a quality policy statement, objectives, commitments by the top management, names, qualifications, experience of persons responsible for the managerial, scientific/technical activities, measurement capability, Traceability of calibration of all measuring instruments to standard, calibration procedures adopted, National/International standards referred/used.
The laboratories should have authorized signatories for approving and issuing calibration certificates for each calibration parameter as mentioned in the scope of accreditation. The laboratory should have an adequate number of qualified and trained staff with at least a degree in Physics or Diploma in Engineering. The team should be headed by a P.G. in Physics or Graduate in Mechanical/Instrumentation Engineering.
The calibration area shall be adequately free from vibrations generated by air-conditioning plant, vehicular traffic or any other such sources. Acoustic noise level shall be maintained for proper performance of calibration. A threshold noise level of 60 dBA is to be maintained as recommended. Adequate level of illumination has to be maintained, fluorescent lighting is preferred to avoid localized heating and temperature drift. The recommended level of illumination is 450-700 lux on the working table with glare index of 19 for the laboratory.
The environmental conditions for the activity of the laboratory shall be such as not to adversely affect the required accuracy of measurements. As possible, only the staff engaged in calibration activity should be permitted entry inside the calibration area. Laboratory should have equipment of required accuracy in respect of each parameter covered. Stability of the standards, accuracy of the values realized through them and repeatability, should be regularly monitored.
Calibration certificates, performance history sheets, working standard details should be held safely by the laboratory. Each equipment should have a record of name, manufacturers name and address, type, range, identification and serial no., date of procurement and commissioning, details of calibration, details of maintenance, performance history with dates. The service manual has to be available at all times.
All the standard equipment of the laboratory should be calibrated periodically against calibration standards of a laboratory accreditated by NABL/ equivalent MRA partners having superior measurement capability or NPL/ other international NMIs. To give further assurance to the accuracy or uncertainty of measurements, a laboratory should be required to participate from time to time, in Proficiency Testing Programmes. There the abnormalities of equipment are detected in terms of En number, through inter-comparisons and the appropriate corrective actions should be taken. The standard equipment shall be replaced/ repaired and re-calibrated with a higher accuracy standard. Reports on such inter-comparisons should be documented with reference. This Proficiency Testing practice should be included in the Quality Manual.
