Читать книгу Continuous Emission Monitoring - James A. Jahnke - Страница 130

For the ultraviolet region of the spectrum, hollow cathode gas discharge tubes, high‐pressure hydrogen or deuterium discharge lamps, xenon arc, and mercury discharge lamps have been used. UV lamps have shorter lifetimes than those operating in the infrared, and it is sometimes difficult to maintain stable UV intensities over the extended periods of time that they operate.