Discrete photometers

Discrete photometers consist of an irradiance source, discrete interference filters, a sample compartment, and detector, along with appropriate electronics for signal amplification and stabilization of detector signals. The optical configuration for a generic photometer is shown in Fig. 1. 

There are two groups of UV analyzer designs photometers and spectrophotometers. Photometers are nondispersive analyzers in which the source radiates over its full UV spectrum, and discrete wavelengths are separated by narrow (2-10 nm) band-pass filters. Most process analyzers are nondispersive. Spectrophotometers are dispersive analyzers in which a prism is used to separate the spectral components of the UV spectrum. Most laboratory analyzers are dispersive. 

For many applications, the UV photometric detection system can fulfill the demands of LC. Table II lists some of the discrete wavelength photometers. 

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