5.3.3 sample rack (cell or cuvette)For example, chemical rack specification calls four-meter is called a cell.There are several wet queue multiple (cuvette) size together, depending on usage. An important principle in use is to measure ultraviolet light in the cell are made of quartz (quartz) only due to ultraviolet light and absorb in the range kaeosamarot. The cells are made of glass, are used to measure in the range of visible light. This means that if we want to measure the substance in the visible light range, it is a good idea to use cells made from glass. Using a quartz cell was not effective, better metering, but wasted empty. The price is very expensive because of the benefits of quartz glass. Figure 12 examples of various types of cuvettesIn addition, an analysis by using spectrophotometric detection if the analysis sensitivity (sensitivity) is low, we can increase the sensitivity to a higher plain.Using the cell width is greater because the rules of beer-Belgian team to absorb the light values of the substance also depends on the thickness of the intermediary of light travel through (l): equation.A = εcl Which cells are used in common with the width ranging from 1-10 cm or if the substance is expensive, and there is a small cell volume below 1 mL.Best to clean the cells just to rinse with distilled water, or to wash with a suitable solvent followed by distilled water is sufficient. Do not scrub because it will make the cells scratched.5.3.4 selection of signal detectors (detector)Good signal detector must have a high sensitivity is even how much light will change slightly, it can detect signs of difference. The current machine.The call parameters are mainly grown FO specification used for detecting 2 signal type: 5.3.4.1 tubes four-apply multiple suppliers (photomultiplier tube PMT;) PMT tube consists of a cathode (cathode) to plaster the surface by substances that can produce light when electrons are nine series called Dino Jade (dynode) each have a high electrical potential will Dino up when light falls on.Dino skin smear substances one pad will cause an electron and then run to beat Dino.At nine until two, three, four; Therefore, the electrons quantity will increase to. 106-107 times then struck out into the anode voltage to signal amplifier. Figure 13 (left) tube of PMT clipart(Right) tube style call FO specification in PMT-meter. 5.3.4.2 four-diode array (PDA photodiode arrays;)This type of signal detector signals can have covers both spectrum using the diode into rows, which can measure covering the spectrum from 200-1100 nm, the signal detector consists of.Four-diode and capacitor (capacitor) for approximately 200-4000 an array concatenation. To start with, a charge over the surface, the diode, diode capacitor capacitor at. When the light falling on the diode will cause an electric charge to destroy the stored charge capacitor. To insert a new battery, which is added to the range of each scan themselves. The quantity of charge that must be put into the new would be directly proportionate to the measured light intensity of each diode. Therefore, the measurement of the amount of light varies throughout the wavelength of spectrum will absorb the substance coming out.
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