The design and preparation of induced transmission filters.

Induced transmission (IT) filters are compared with other types of narrow-band filters and their advantages outlined on the basis of a general expression for spectral transmittance. A method of design is described which avoids the use of admittance charts and can be applied to optimize the performance of an IT system at various stages during its preparation. Finally, methods of monitoring are discussed with emphasis on the theory of a technique particularly useful for IT filters for the ir.