Thermoelectric cooling process

The slow-scan CCD, also called the scientific CCD, or in the spectroscopy literature simply CCD, is the detector of choice for most applications of Raman spectroscopy. A well-designed CCD has essentially zero dark current, very low readout noise, and high quantum efficiency (peak 45—70% near 700 nm) in the visible region of the spectrum. However, the response drops quickly above 800 nm and there is no photon response above 1.05 J m. For routine spectroscopy or process control, thermoelectrically cooled (to about —40° C) CCDs are adequate. Although these detectors are somewhat noisier than detectors operated at —100° C or lower, the former do not require liquid nitrogen cooling. The general properties and spectroscopic applications of the CCD have been reviewed (22). 

Process Instruments, Salt Lake City, UT PI-100 300 mW diode laser (785 nm) F/1.4 spectrograph, 6 cm CCD, thermoelectric cooling Unfiltered fiber optic probe... 

Raytek (Fluke) CS-100, GS-lOO, TF-100, TIP-450 (all using the MP-50 Thermalert line scanner) Optomechanically scanned each system for a different process application, modular thermoelectrically cooled, high-resolution analog and digital outputs various wavelengths operate with integral control system or host computer. 

Land FTI-6 Remote-controllable module featuring thermoelectrically-cooled 256 x 256 element HgCdTe FPA detector, 3.2- 4.2 pm, for process control and plant monitoring extensive diagnostic software. 

Figure 14. The read/write process in a smectic A thermoelectric scattering cell. Writing is accomplished by local heating of the cell to the isotropic state (b), which on cooling can be induced to form either a clear homeo-tropic state (a) if a field is simultaneously applied, or to a scattering focal-conic state (c) in the absence of a field. The field has no effect in the absence of simultaneous heating.

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