Ultraviolet/infrared detectors

Other fire protection features have been incorporated into CNG refueling facilities such as methane detectors to warn of leaks from the dispenser, and automated fire suppression systems activated by ultraviolet/infrared detectors. Dry chemical is the preferred fire suppression material since water line protection from freezing is difficult in outdoor settings. The methane detectors can also be used to shut down the compressor and dispenser if desired. 

Facilities where EVs are charged or stored should be protected from fire. The same fire protection technologies used few conventional vehicles should be used for EVs. In charging facilities, sprinkler systems can be used because chargers are designed to withstand the water exposure that a sprinkler system would cause. Smoke alarms and ultraviolet/infrared detectors are recommended for EVs, just as they would be for conventional vehicles. 

Advantages. Like ultraviolet detectors, infrared detectors have their advantages and limitations. Several advantages of IR units make them valuable in certain installations ... 

Fire detectors—dry-pilot head and pneumatic rate-of-rise heat detectors are the most frequent devices used. A dry pilot head detection systems uses 165°F (74°C) V2-in sprinkler head with air pressure maintained in the piping. When the sprinkler opens the air is released resulting in the sprinkler valve opening. Other types of detectors include ultraviolet, infrared flame detectors, or thermostatic cable heat detection. 

The use of a continuous GPC viscosity detector in conjunction with a DRI detector permits the quantitative determination of absolute molecular weight distribution in polymers. Furthermore, from this combination one can obtain Mark-Houwink parameters and the bulk intrinsic viscosity of a given polymer with a GPC calibration curve based only on polystyrene standards. Coupling these two detectors with ultraviolet and infrared detectors then will permit the concurrent determination of polymer composition as a function of molecular weight and... 

A photomultiplier tube is a sensitive detector of visible and ultraviolet radiation photons cause electrons to be ejected from a metallic cathode. The signal is amplified at each successive dynode on which the photoelectrons impinge. Photodiode arrays and charge coupled devices are solid-state detectors in which photons create electrons and holes in semiconductor materials. Coupled to a polychromator, these devices can record all wavelengths of a spectrum simultaneously, with resolution limited by the number and spacing of detector elements. Common infrared detectors include thermocouples, ferroelectric materials, and photoconductive and photovoltaic devices. 

Mass concentration detectors include the differential refractometer, ultraviolet and infrared detectors. 

Determination of the average chemical composition and polymer composition by size-exclusion chromatography (SEC) has been reported in the literature. Two different types of concentration detector or two different absorption wavelengths of an ultraviolet or an infrared detectors are employed the composition at each retention volume is calculated by measuring peak responses at the identical retention points of the two chromatograms. 

As shown in Section 25A, the components of infrared instruments differ considerably in detail from those in ultraviolet and visible instruments. Thus, infrared sources are heated solids rather than deuterium or tungsten lamps, infrared gratings are much coarser than those required for ultraviolet/visible radiation, and infrared detectors respond to heat rather than photons. In addition, the optical components of infrared instruments are constructed from polished solids, such as sodium chloride or potassium bromide. 

Infrared Absorption Detectors. Two types of infrared detectors have been offered commercially. The first is a filter instrument similar in design to that shown in Figure 16-13. The second, and more sophisticated, type of infrared detector is based on Fourier transform instruments similar to those discussed in Section I6B-1. Several of the manufacturers of Fourier transform infrared (FTIR) instruments offer accessories that permit their use as HPLC detectors. Infrared detector cells are similar in construction to those used with ultraviolet radiation except that windows arc constructed of sodium chloride or calcium fluoride. Cell path lengths range from 0.2 to 1.0 mm and volumes from 1.5 to 10 pL. 

Ultraviolet or infrared detectors (see Figure 6-3) that sound an alarm when the radiation from flames is detected. 

In this regard, various analytical methods have been developed and their potential for the VOO authentication has been evaluated. Thus, spectroscopic tools, such as FT-near-infrared spectroscopy, FT-Raman spectroscopy, fluorescence and ultraviolet-visible detectors, and chromatographic techniques have been widely used in the field of VOO authentication [43-48],... 

The combination of chromatographic separation with Fourier transform infrared spectroscopy has significantly improved the analysis of complex mixtures [109]. In chromatography/ FT-IR systems, an infrared detector providing information on the structure of separated species is used instead of standard bulk chromatography detectors such as thermal conductivity, flame ionization, ultraviolet, or fluorescence these detectors can be used for quantitative analysis when the identities of the mixture components are known. 

Infrared and Ultraviolet. These detectors have sensing elements responsive to radiant energy outside the range of hnman vision. 

By using heat detection devices operating on the rate-of-rise or fixed-temperature principle, or other devices such as ultraviolet or infrared detectors designed for individual hazards, it is possible to apply water to a fire more quickly than with systems in which operation depends on opening of sprinklers only as the fire spreads. 

Purification was performed by preparative TLC. The compounds obtained were analyzed by Ultraviolet, Infrared and Nuclear Magnetic Resonance spectroscopy and by Gas Chromatography-Mass Spectrometry (GC-MS). The GLC analysis was carried out with a Perkin Elmer mod.990 equipped with a flame ionization detector, on a glass column OV 17 3%. NMR spectra were measured with a Varian 100 MHz for solutions in deuterated chloroform with tetramethyl-silane as internal standard. IR spectra were performed on a Perkin Elmer mod. 157 G in chloroform solution. GLC-MS spectra were carried out with an LKB 9000 at 70 eV. and a glass column OV 17 at 235 C. 

A typical SEC system consists of a solvent reservoir, pump, injector, packed column or columns, and detectors as illustrated in Fig. 6. The most widely used packing material is polystyrene gel. Detection methods include those based on refractive index ultraviolet, infrared, viscosity and light scattering. The detectors must be very sensitive to small changes because low concentrations (0.1-2 wt%) of polymer are injected to prevent overloading of the columns. 

Single ultraviolet/infrared (UV/IR) flame detector at not more than 25% LEL... 

The methods described here have been used successfully to test many infrared detectors, most in the 3-5 um region, but many in the 1-3 um and 10-12 m regions. FPAs are now built that respond to X-rays, ultraviolet, visible, and very short IR wavelengths. It is reasonable to ask if the methods described here can be applied to other spectral regions. 

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