Certified filters, or measurement reference materials, are used as standards to test the fundamental parameters of analytical UV/VIS absorption spectrophotometers:
- Resolution or Spectral Bandwidth
- Stray Radiant Energy (SRE) or Stray Light
- Wavelength Scale
- Photometric Scale
Stranaska Metrology Laboratory (SML) does not calibrate spectrophotometers per se; instead, SML calibrates and certifies reference material filters that are then used to qualify or to evaluate the performance of spectrophotometers.

