Accrediting Artifact Calibration of a Multi-Function Calibrator

A decade ago, two companies introduced electronic instruments incorporating Artifact Calibration, a technology by which an instrument calibrates itself using a small number of external standards, thereby significantly reducing the cost of calibration and simplifying their path of traceability. Some national standards laboratories have been cautious about accepting Artifact Calibration, perhaps because most of the external verification traditionally done is replaced by characterizations performed inside the instrument beyond the control and oversight of the operator. However, the large reduction in cost of ownership that comes with Artifact Calibration is a strong motivation for broader acceptance, particularly for high accuracy instruments whose calibration would otherwise require time-consuming procedures and more expensive standards. Toward this end, the national standards laboratories of the Netherlands (Nederlands Meetinstituut or NMi), Sweden (Sveriges Provnings-och Forskninginstitut or SP), and Germany (PhysikalischTechnische Bundesanstalt or PTB) undertook an independent evaluation of Artifact Calibration as implemented in the Fluke 5700A with the goal of increasing acceptance of Artifact Calibration. This paper gives background for the project and briefly reports preliminary project results and conclusions. A more complete report will be published later in 1998, and among others will be presented at the October 1998 meeting of the DC/LF experts group of the European co-operation for Accreditation (EA).