FREQUENTLY ASKED QUESTIONS ABOUT SPECIALTY GASES

What gas mixtures are NIST-traceable?

Most of Scott Specialty Gases' mixtures can be NIST-traceable either directly or by weight. Direct NIST traceability is achieved by laboratory analysis of your gas mixture on an instrument directly calibrated with gas reference material from NIST such as an SRM (Standard Reference Material) or NTRM (NIST-Traceable Reference Material). Using a GMIS (Gas Manufacturer's Intermediate Standard) to calibrate an instrument results in traceability but it is no longer directly traceable.

NIST-traceable by weight applies to process traceability rather than analytical traceability. In order to have process traceability, the blending method used for your gas mixture must also be directly calibrated with reference material from NIST. For example, if a gravimetric blending scale is calibrated with NIST Class 1 Weights or the older NIST Class S Weights, the resulting product is said to be "NIST-traceable by weight."