Detection systems flame detectors

AH gas-fired power plants require oxygen analy2ers to ensure that air has not been drawn into the piping system. Oxygen intake can lead to the presence of an explosive mixture in the pipeline before the fuel reaches the burner or combustor 2one. When gas-fired units are located in an enclosed area, multiple ultraviolet flame detectors are used to shut down equipment and flood the area with CO2 or a chemical fire suppressant whenever a spark or flame is detected. 

The effort required to establish identity of a nitrosamine in an environmental sample depends on the nature of the problem and the specificity of the primary detection system. TEA response is much stronger evidence of identity than response from a flame ionization or nitrogen-specific detector. If TEA response is supported by chemical (9) or ultraviolet photolysis (8) supporting data, identification is adequate for many... 

Security and safety Intruder alarm Security systems Fire detection systems, with sensors for - temperature - toxic gases like CO, C02, exhaust gases, smoke, etc. - combustible gases like CH4, C2H6 flame detection, fire detectors, caravans with gas detectors, etc. 

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 amount of cresol in the concentrated extract can then be determined by high performance liquid chromatography (HPLC) (DeRosa et al. 1987 Yoshikawa et al. 1986) or gas chromatography (GC) coupled to either a flame ionization detector (FID) or a mass spectrometer detection system (Angerer 1985 Needham et al. 1984). Separation of the cresol isomers by gas chromatography is readily accomplished, and the use of an appropriate internal standard allows the determination of their concentrations. Although exact detection limits were not given for the above GC methods, a concentration of 10 ppm appears to be readily determined. 

In theory, the MS system used in these techniques is no different from any other detection system (e.g. a UV detector or flame ionization detection), except that it is a good deal more expensive. However, its main advantage over other detectors is the additional information about the analyte that it provides and the greater sensitivity it offers. 

The flame photometry detector is specific for compounds containing sulphur or phosphorous. Compounds eluting from the column are burned in a flame hot enough to excite these elements and induce photonic emission, which is detected by a photomultiplier (see Fig. 2.12). Optical filters are used in the detection system to... 

Flame ionization detection has been proposed in the past as a universal detection system that is compatible with gradient elution. According to Moreau et al., the limit of detection of this detector is about 1 fig of each lipid component, which is comparable to or slightly worse than ELSD... 

The non-polar chlorinated hydrocarbon pesticides are routinely quantified using gas chromatography (GC) and electron capture(EC) detection. Alternate detectors include electrolytic conductivity and microcoulometric systems. Organophosphate pesticides which are amenable to GC are responsive to either the flame photometric detector (FPD) or the alkali flame detector (AFD). Sulfur containing compounds respond in the electrolytic conductivity or flame photometric detectors. Nitrogen containing pesticides or metabolites are generally detected with alkali flame or electrolytic conductivity detectors. 

In areas where the possibility of fire is the greatest, a high speed ultraviolet detection system is employed. The ultraviolet eyes detect the presence of a flame and are interconnected with a high speed water deluge system. In some areas the fire detection devices have process shutdown capabilities. The detectors are situated such that the entire hazardous area can be monitored at all times. They are equipped with air shields that not only cool the detector but also blow clean air across the face of the lens, keeping any dust from accumulating on the lens, which assures detection capability. Further, the detectors have a built-in test lamp which serves as a check of... 

Determination of Nerve Agents In contrast to those rather unusual methods, GC coupled to diverse detection systems, e.g. flame ionization detector (FID), nitrogen-phosphorus detector (NPD), flame photometric detector or mass spectrometer, as well as liquid chromatographic (LC) methods, represent the most common techniques for OP determination especially for biological samples. These methods offer high resolution, sufficient limits of detection, good reproducibility, and robust hardware devices. For more detailed information readers are referred to recent review articles (Hooijschuur et al, 2002 John et al, 2008). 

If optimum chiral resolution and high efficiency sample clean-up, the claims of first priority in enantioselective analysis (sections 6.2.3.1. and 6.2.S.2.), are realized rather simple detection systems, such as flame ionization detectors (FID) are suitably used. 

The experiment can readily be extended to other systems, for example, a nitric acid/nitrogen oxide vapour produced by adding concentrated nitric acid to copper. The quantitative exercise could simply be carried out with flame ionisation detection however, if both detection systems are available this forms the basis for a study and comparison of relative detector response using both total ion and selected ion monitoring. 

The elution flow-rate is an important parameter in column preconcentration which is usually optimized for maximum sensitivity. However, the speed of elution is also a crucial factor for the efficiency of on-line preconcentration systems, because in most cases the eluent flow is connected directly (some after merging with reagent streams) with the detector. This is particularly important for detection systems which require a certain sample delivery rate for optimum response, e.g., the flame AA or ICP spectrometer, and will be discussed in more detail in section 4.6.3. 

Two other detection systems which have been used for the quantitation of phosphohpids are flame ionisation detectors (Kiuchi et al.,... 

---