Characteristics of Infrared Detectors

Spectral characteristics of infrared detectors. (From hide, D. R., CRC Handbook of Chemistry and Physics, 79th ed., Boca Raton, FL CRC Press, 10-216,1998.)... 

The selection of the modulation frequency with which to carry out infrared (and VCD) measurements is influenced by the characteristics of the detector used for the measurement. For semiconductor detectors, such as InSb and HgCdTe, the response (relative to the noise level) of the detectors increases with... 

W. L. Eiseman, J. D. Merriam, and R. F. Potter, Operational Characteristics of Infrared Photodetectors P. R. Bratt, Impurity Germanium and Silicon Infrared Detectors E. H. Putley, InSb Submillimeter Photoconductive Detectors... 

The convenient photon detectors discussed in the previous section cannot be used to measure infrared radiation because photons of these frequencies lack the energy to cause photoemission of electrons as a consequence, thermal detectors must be used. Unfortunately, the performance characteristics of thermal detectors are much inferior to those of phototubes, photomultiplier tubes, silicon diodes, and photovoltaic cells. 

An obvious application of solid-state cooling which takes advantage of these characteristics is the cooling of infrared detectors. Another application is the temperature control of small components relative to some low-temperature bath. The main disadvantage This is proven rigorously by Kooi et al. [ ]... 

Thermal detector, infrared - A type of infrared detector that changes electrical characteristics as a function of temperature typically, thermal detectors have slow response, (on the order of milliseconds) broad spectral response and usually operate at room temperature thermal detectors are commonly used in IR radiation thermometers and in some imagers. 

The requirement for the uniform linear motion of the movable mirror in the continuous-scan type is imposed mainly by the frequency-response characteristics of the detector for the main interferometer. The response of the detectors to the beams (indicated by (g) and in Figure 5.4) of the laser interferometer is usually rapid, so that effects arising from the instability of the motion of the movable mirror which changes the modulated frequency can be disregarded. In contrast, the response characteristic of thermal detectors such as a pyroelectric detector commonly used for detecting the infrared beam from the main interferometer is not as rapid as that of the laser-interferometer detectors. As a result, any... 

All radiometric devices must convert infrared energy into electrical signals. The fundamental properties of infrared converters, commonly called detectors, are analyzed in Section 5.10. In Section 5.11 the operating principles, noise limitations, and several temperature to voltage conversion mechanisms of thermal detectors are treated. Properties and noise characteristics of quantum detectors are the subject of Section 5.12. In many cases radiometric instruments must be calibrated in intensity and wavenumber. For best results calibration techniques are part of the instrument design. Several calibration methods are treated and their merits discussed in Section 5.13. Finally, Section 5.14 deals with considerations encountered in the... 

We have found the Hamamatsu user s guide Technical Information SD-12 Characteristics and Use of Infrared Detectors to be very helpful - it is quite complete, and offers some specific circuit information. 

The cost constraint usually dictates that we use a detector that operates at room temperature (so no cooling is required), or requires only minimal cooling, or requires only temperature stabilization near room temperature. Thus, any cooling requirement for single detector assemblies is usually satisfied with a heat sink or a thermoelectric (TE) cooler, perhaps with a temperature sensor and a feedback circuit. The Hamamatsu (2014) Handbook Technical Information SD-12 Characteristics and Use of Infrared Detectors is a useful reference. 

Hamamatsu website This discusses IR components accessed July 2014 at http //www.hamamatsu.com/us/en/index.html. We found their Technical Information SD-12 Characteristics and use of infrared detectors to be particularly useful Accessed July 2014 at http //wwwJiamamatsu.com/resources/pdf/ ssd/infrared techinfo e.pdf... 

Rasmussen [82] describes a gas chromatographic analysis and a method for data interpretation that he has successfully used to identify crude oil and bunker fuel spills. Samples were analysed using a Dexsil-300 support coated open tube (SCOT) column and a flame ionisation detector. The high-resolution chromatogram was mathematically treated to give GC patterns that were a characteristic of the oil and were relatively unaffected by moderate weathering. He compiled the GC patterns of 20 crude oils. Rasmussen [82] uses metal and sulfur determinations and infrared spectroscopy to complement the capillary gas chromatographic technique. 

The chromatograph (Waters Associates) was fitted with PL Gel columns (Polymer Laboratories Ltd.) and two Infrared detectors in series. Chloroform was used as the eluant. Infrared detectors were used because the tin containing acrylic mommier has a characteristic carbonyl stretching frequency at 1620 cm which is well removed from that of other acrylic monomers which have, carbonyl absorptions at the more characteristic wavenumber 1720 cm . Both peaks obeyed the Beer Lambert law. A typical chromatogram showing the separation of residual monomers and polymer Is shown in Figure 1. 

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