Method for detecting whether AA-1800 atomic absorption element lamp is stable - Database & Sql Blog Articles

Method for detecting whether AA-1800 atomic absorption element lamp is stable

Keywords: atomic absorption element lamp; US instrumentation ; AA-1800 I. Measurement of the emission intensity of the emission intensity of the lamp. Complex test equipment is required. At present, the elemental lamps produced at home and abroad do not give the absolute value of the emission intensity. Relative value indicators are also different due to different power supply modes of different types of instrument lamps (such as pulse power supply frequency, duty cycle) sensitivity, optical path loss rate, etc. Manufacturers are not likely to provide a fixed value of ten. In order to identify the relative emission intensity of the elemental lamp, you can use the instrument with the negative high voltage and slit to achieve the fullness of the lamp (ie T=100%). Compare the size, or compare the negative high voltage under the same lamp current. Second, the preheating time and the length of time before the stable lamp reaches stable work is a sign of the maturity of the lamp. The general rule is no more than 30 minutes. The purpose of preheating is to make the overall temperature of the lamp cathodes uniform, the density of atomic vapor clouds generated by cathode sputtering and evaporation is constant, and the excitation process is stable. At this time, the internal resistance of the lamp tends to be constant, and the emission intensity of the lamp reaches a steady state. The copper element lamp is continuously recorded for 30 minutes, and the drift should be less than 1%. The drift of other elemental turbulence lamps recorded continuously for 10 minutes should be less than 1%. Third, the background noise background refers to the luminous intensity of the two measurements of the resonance line. The main reason for the background is that the cathode material and the impurity elements in the carrier gas generate lines. For cathode lamps, the background produced by the lamps themselves is very small, typically less than 1%. In the case of noise test, in the case of no spray, the test result is actually the superimposed value of the lamp body noise. When the instrument range is extended by 10 times, observe the peak range of fluctuations on the recording line, and it is required that the peak value of the upper and lower peaks does not exceed 5 grids, that is, less than 0.5% within 3 minutes.