Traceability and Uncertainty of Technical pH Buffer Solutions

摘要

The DURACAL pH buffer family offers the advantage of high stability, high resistance against contamination, easy handling, and long lifetime. Furthermore, DURACAL provides features that are common to Secondary Reference Solutions, namely low uncertainty, and a documented traceability. In order to provide full reliability of in-house pH determination, a representative sample of each production lot is verified in an external and independent laboratory accredited for pH measurement. This paper discusses the concept for the determination of the true value of a DURACAL buffer. Traceability to international standards is documented, and finally, the uncertainty budget for the complete measurement chain is established. With a documented traceability and uncertainty budget, the DURACAL family is classified as Certified Reference Material (classification according to [2]).