A filter designed to inhibit the passage of a target material, such as moisture, ions, particulates, or selected wavelengths of light. In microscopy, barrier filters selectively block the excitation radiation wavelength, so that only the emission, or fluorescence, radiation can be seen.
Sources Checked for Data in Record
- Walter C. McCrone, John Gustave Delly, The Particle Atlas, W. McCrone Associates, Chicago, IV, 1972
- Book and Paper Group, Paper Conservation Catalog, AIC, 1984, 1989
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998