An internal reflectance element assembly, that is defined by a crystal that has at least one measured dimension of about 5 mm or greater that is held in a holder structure shaped to hold the crystal, and a backer plate to secure a sample to the crystal.
STATEMENT REGARDING FEDERAL RIGHTS
 This invention was made with government support under Contract No. W-7405-ENG-36 awarded by the U.S. Department of Energy. The government has certain rights in the invention.