15 C.F.R. § 200.104
Often the performance of a device or structure can be evaluated at the user's laboratory by comparing its response to unknown materials with its response to a stable, homogeneous reference specimen which has been well-characterized with regard to the physical or chemical property being measured. For information regarding carefully characterized materials see Subchapter B, Chapter II, Part 230, of this title. The Office of Standard Reference Materials in the NIST National Measurement Laboratory administers a program to provide many types of well-characterized materials that are needed to calibrate a measurement system or to produce scientific data that can be readily referred to a common base. NIST SP 260 is a catalog of Standard Reference Materials available from NIST.
15 C.F.R. § 200.104