Detectors Deuterium lamp

The sensitivity of the method is influenced by the type of detector and lamp used in the detector. Deuterium lamps have weak energy in the wavelength range that carotenoids ab-... 

R = recorder, I = integrator, E = detector, Pr = sample (TLC plate), S = mirror, M = monochromator, L = lamps (incandescent lamp , deuterium lamp 0 and mercury lamp G), FI = cutoff filter. 

Variable-wavelength detector, showing deuterium lamp, optical path, reference photodiode and monochromator. 

On a PDA detector, using the spectral energy output from the deuterium lamp, one can also use the sharp calibration lines at 486 and 656nm (Balmer line). 

There are two basic types of multi-wavelength detector, the dispersion detector and the diode array detector, the former being the more popular. In fact, today very few dispersion instruments are sold but there are many still used in the field and so their characteristics will be discussed. Both types require a broad emission light source such as deuterium or the xenon lamp, the use of the deuterium lamp being the most widespread. 

As well as noise arising due to particular electrical or optical devices, noise may be caused by external sources, such as mechanical vibrations, or pick-up of external electrical signals. Detector noise tends to increase with the age of the instrumentation. Certain components have limited lifetimes and are considered as expendable. An example is the deuterium lamp of a UV absorbance detector, which typically has a rated life of 2000 h or so. After this time the lamp will probably not fail completely. 

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