Protective coating for analysis cell - esp. for gas analysis by non-dispersive IR spectroscopy

摘要

A surface coating for an analysis cell, esp. for gas analysis by non-dispersive IR spectroscopy consists of one of the following: (i) a Au layer (2) protected by an overlying layer (4) of SiC and/or Si02; (ii) a protective SiC and/or Si02 layer formed on the highly reflective pure Al surface of the cell; (iii) a protective SiC and/or Si02 layer formed on the polished alloy steel surface of the cell; (iv) a protective SiC and/or Si02 layer formed on the polished Cu alloy surface of the cell; or (v) a protective layer of thickness such that it is free of pinholes. Prodn. of coating (i) by plasma-enhanced CVD is also claimed. ADVANTAGE - The coating provides resistance to materials and gases to be analysed (e.g. aggressive gases from waste incineration and other processes in the chemical industry), provides long term stability without surface changes and provides resistance to mechanical and thermal shock.