A standard reference material interface for a Raman probe includes a locator including a housing having a first end and a second end, the first end including an attachment portion configured to mate with an attachment portion of the Raman probe. The locator defines a central axis that intersects the first end and the second end. The standard reference material interface also includes a hermetically sealed standard reference material enclosure positioned at the second end of the housing and enclosing a standard reference material. An optical port is positioned within the housing between the Raman probe and the standard reference material relative to the central axis. The optical port includes a window.