Nist traceable calibration standards are available as freestanding films, and can also be deposited on KBr windows to eliminate fringing
Polystyrene calibration films traceable to Nist 1921 are available in the 38um pathlength that matches the Nist standard and also in sets of two different pathlengths.
Use of two pathlengths enables more precise calibration of FTIR instruments.
International Crystal Laboratories's calibration standards are available as freestanding films, and can also be deposited on KBr windows to eliminate fringing.
All Nist traceable films are individually calibrated and come with a certificate tracing the wavenumbers to a Nist 1921 polystyrene film.
ICL polystyrene films are radially symmetric (US Patent 6,254,931), which eliminates the orientation effects of extruded films.
