Hollow Cathode Lamp Function

The greater the intensity of the analytical line the lower the noise level.

Hollow cathode lamp function. This line should be of sufficient spectral purity and intensity to achieve a linear calibration graph with low noise level from the aa spectrometer. A typical hollow cathode lamp construction appears in figure 1. Hollow cathode effect was first observed in 1916 by friedrich paschen a german physicist known for his work on electrical discharges. For atomic absorption spectrometers and as a frequency tuner for light sources such as lasers.

These lamps don t really exist outside of laboratory settings meaning most people will have never seen one. Hollow cathode lamps hcl are discharge lamps designed for use in atomic absorption aa instruments. A hollow cathode lamp is a light source primarily used for scientific purposes. Hollow cathode lamps working totally depends on the hollow cathode effect.

Most of the time a hollow cathode lamp is used as a method of tuning in specific light frequencies. The hollow cathode lamp hcl uses a cathode made of the element of interest with a low internal pressure of an inert gas. A low electrical current 10 ma is imposed in such a way that the metal is excited and emits a few spectral lines characteristic. In looking into the topic i ve read that continuum radiation is not preferred in aas.

They consist of a cathode made from the element of interest an anode and an inert filler gas contained in a glass envelope. Hollow cathode lamps contain a cathode of the analyte element and an anode and are filled with a noble gas. 1 in 1955 it was proposed that hollow cathode lamps are good emission sources for monochromatic radiation and thus for atomic absorption spectroscopy aas. The hollow cathode lamp the primary requirement of a hollow cathode lamp is to gen erate a narrow emission line of the element which is being measured.

Such differences in the measured noise level between different lamps are quite normal. A hollow cathode lamp hcl is type of cold cathode lamp used in physics and chemistry as a spectral line source e g. Each analytical line from a hollow cathode lamp has a characteristic intensity that relates to the observable signal to noise level of the atomic absorption instrument. Heraeus offers the widest selection of single and multielement coded non coded in low and high current 37 mm and 50 mm lamps in the industry.

Hollow cathode lamps from an atomic absorption spectrometer. In addition to dc operation hollow cathode lamps may be operated by supplying pulsed current at about 50 200 hz to increase the average amount of light that can be obtained from the lamp. Atomic absorption profile is the term used to describe the range of wavelengths over which it is possible for an atom to absorb radiation.