What is the advantage of hollow cathode lamp?
Advantages of Hollow Cathode Lamps [Why HCL in AAS?] Substantially Low Price. Variety of single- and multi-element coded / non-coded in low and high-current, 37 mm and 50 mm lamps. Long life due to higher gas volume. Clear signals and low distortion due to special cathode technology.
What is hollow cathode lamp disadvantages?
The only disadvantage of such lamps is that the useful life of some elements can get shortened as higher current can be passed but this single disadvantage far outweighs the advantages over conventional lamps.
What is the major disadvantage of hollow cathode lamp in atomic absorption spectrometry?
Hollow cathode lamps HCLs are almost ideal line sources for AAS because of their high stability and narrow linewidth (0.002 nm), but their relatively low intensity is a disadvantage for AFS.
Why is the cathode designed with a hollow configuration?
There are two reasons for the hollow cathode design. One is that the configuration helps to focus the light beam allowing a higher intensity of photons to be directed toward the flame or furnace. The second is that it helps prolong the lifetime of the lamp.
What material is the cathode in hollow cathode lamp?
Answer: The most common source for atomic absorption measurements in the ‘hollow-cathode-lamp’, which essentially consists of a Tungsten anode (A) and a cylindrical cathode (HCL) sealed in a glass tube (B) that is duly filled with neon or Argon (C) at a pressure of 1 to 5 torr.
What are the advantages in atomic absorption of a heated graphite atomizer over a flame atomizer?
The inert environment inside the graphite tube This helps prevent formation of stable oxides of refractory elements. On the other hand formation of stable oxides in flames leads to loss of analyte atoms and results in lower sensitivities.
What is the main disadvantage of AAS?
The main disadvantages of AAS are as follows: only solutions can be analyzed. less sensitivity compared to graphite furnace. relatively large sample quantities are required (1-3 ml)
Why do we use hollow cathode lamp of the same element to be analyzed in AAS?
The essential feature of a hollow cathode lamp is to generate a narrow emission line of the element which is to be tested. It should give narrow emission line of the constituent elements. Such lines should be well resolved to be free of interferences and also have sufficient intensity.
What is hollow cathode lamp and which method applies it?
Hollow cathode lamps are essentially two electrodes enclosed in a low-pressure fill-gas. The cathode is made from the mater- ial that is to be determined. The fill-gas is either neon or argon. There is a two-step process to have light emitted.
What are the differences between the hollow cathode lamp and electrode less discharge lamp?
The energy will vaporize and excite the atoms, inside the bulb, causing them to emit their characteristic spectrum. Electrodeless discharge lamps are typically much more intense and in some cases, more sensitive than comparable hollow cathode lamps. They therefore offer a better precision and lower detection limits.
