Think Small: Low-Cost Optical Spectral Measurements for Chemical Sensing

The term spectral engine is not new and is normally intended to indicate the integration of optics and electronics to form a single measurement package. In the system described in this column, the term is extended to include the close-coupling of the measurement system to the sample via nonimaging optics.

Emil W. Ciurczak
This column focuses on the spectral engine concept and its role as an integrated component into continuous in-line/on-line measurement systems. One obvious mode of integration is the combination of the spectral sensor within a process analytical measurement system, and this is discussed in terms of the New Sample Sensing Initiative (NeSSI) miniaturized sampling systems, pioneered by the Center for Process Analytical Chemistry (CPAC), which is the industry–academia consortium based at the University of Washington, Seattle. Other forms of integration can include combinations with other small-scale sampling systems and microfluidic devices. Examples of applications are provided ranging from water quality measurements to the compositional measurements of organic sample streams.

View Full Article