Luminometers, commercial

The luminometer index (ASTM D 1740) is a characteristic that is becoming less frequently used. It is determined using the standard lamp mentioned above, except that the lamp is equipped with thermocouples allowing measurement of temperatures corresponding to different flame heights, and a photo-electric cell to evaluate the luminosity. The jet fuel under test is compared to two pure hydrocarbons tetraline and iso-octane to which are attributed the indices 0 and 100, respectively. The values often observed in commercial products usually vary between 40 and 70 the official specification is around 45 for TRO. 

Stanley, P. E. (1992). A survey of more than 90 commercially available luminometers and imaging devices for low-light measurements of chemiluminescence and bioluminescence, including instruments for manual, automatic and specialized operation, for HPLC, LC, GLC and microtiter plates. Part I descriptions. T. Biolumin. Chemilumin. 7 77-108. 

Stanley, P. E. (1999). Commercially available luminometers and imaging devices for low-light level measurements and kits and reagents utilizing... 

Commercial available luminometers, imaging devices, and reagents, survey update 5 Commercial available luminometers, fluorometers, imaging devices, and reagents, survey update 6 Teaching... 

Photodiodes and photomultiplier tubes (PMTs) are the detection devices commonly found in commercial luminometers. Even if improvements in photodiodes have made them suitable for some applications, PMTs are still the detectors of choice for measuring extremely low levels of light. 

Commercial luminometers range from low-cost manual single tube instruments to fully automated high-capacity machines and have been reviewed previously (10). However, application-specific requirements are rarely discussed, and the first-time user will require some guidance in matching an instrument to the chemistry or chemistries to be used. 

The light emission is proportional to the amount of a protein for it participates in the reaction directly. The relationship between obelin concentration and bioluminescence is unlimitedly linear. A high quantum yield of the obelin bioluminescence is 25-30%, and the lack of the background signal due to the high ionic specificity of obelin to Ca, make it possible to determine this protein down to 10 mole by using modem commercially available luminometers. 

Although there are still a few commercially available instruments for phosphorescence measurements based on mechanically chopped systems, nowadays most of the commercial luminometers used for phosphorescence measurements are based on pulsed-source/gated detections. These pulsed instruments are typically equipped with a high-power xenon flash-lamp and a photomultiplier detector. 

The awareness of the advantages of luminometry have prompted improvement in, and commercial availability of luminometers. Three systems in frequent use are firefly, bacterial luminescence and luminol chemiluminescence. The principles and applications of each of these systems are described below. 

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