The Traceability Tree

 

The Traceability Tree Explained

The National Physical Laboratory (NPL), is based in Teddington, and is where the primary calibration standards are housed.

NPL do calibrate items themselves, but they mainly deal with the high level standards, (which is reflected in their pricing), and not the industrial instrumentation commonly found in the work place.

 

This is where the calibration traceability tree comes in.

 

Instruments that have been calibrated to UKAS (United Kingdom Accreditation Service), have been calibrated using approved procedures, with approved standards by approved calibration personnel.

 

The calibration standards used at industrial Calibration are calibrated to UKAS, which in turn means that the UKAS Laboratory we sent our standards to, also had their calibration standards calibrated to UKAS via a higher level calibration laboratory than themselves, and that laboratory had their standards calibrated by an even higher level laboratory, and so on, until we get back to the National Standards (housed at NPL).

 

The whole traceability tree back to NPL would not be practical.

 

UKAS certificates imply credibility and traceability back to NPL.

 

Our “in-house” certificates make reference to the UKAS Calibration certificates of the standards which were used during calibration (this is the start of the traceability tree).

 

The traceability information on our “Traceable Calibration” certificates show which calibration standard was used to calibrate the instrument under test and it’s current UKAS Certificate No.

For example, our calibration standard, Asset No. BIC1680 refers to a Fluke 9100 Multifunction Calibrator and the current UKAS Calibration Certificate No. is 034138.

This Certificate Number. can be traced back to the National Standards via the traceability tree.

The traceability information on our “Traceable Calibration” certificates show which calibration standard was used to calibrate the instrument under test and it’s current UKAS Certificate No.

For example, our calibration standard, Asset No. BIC1680 refers to a Fluke 9100 Multifunction Calibrator and the current UKAS Calibration Certificate No. is 012345.

This Certificate Number. can be traced back to the National Standards via the traceability tree.