Electrodeless lamps characteristics

In general, the electrodeless lamp contains a small amount of mercury and a neutral starter gas. The mercury pressures during its operation are in the 5-20 bar range, which is higher than for arc lamps, with pressures only in the 1-2 bar range. The characteristics of fhe lamp can be modified by fhe addition of mefal halides in confrolled quanfifies to the gas. The frequently used D or V lamps contain iron or gallium salts, respectively. Some characteristics of microwave-powered lamps are in Table 3.1. 

Source of Radiation The radiation source for FAAS instrumentation is quite similar to that of other AAS techniques, such as ETAAS or CVG-AAS (CV-AAS and HG-AAS). The one most commonly applied is the line source (LS), which generates a characteristic narrowline emission of a selected element. There are two principal LSs for AAS the hollow cathode lamp (HCL) and the electrodeless discharge lamp (EDL).8... 

Line source In atomic spectroscopy, a radiation source that emits sharp atomic lines characteristic of the analyte atoms see hollow-cathode lamp and electrodeless discharge lamp. 

A unique characteristic of the electrodeless system is the modular lamp construction. The basic lamp is 10 in. in length, and because there are no electrodes, it emits from the entire length. Thus, a 40-in. web can be cured by butting four 10-in. modules next to each other. 

Electrodeless discharge lamp (EDL). This is a tube which contains the element to be measured in a readily vaporized form (often as iodides). A discharge is produced in the vapour by microwave or radio frequency induction. The lamp emits very intensive characteristic radiation of the analyte. 

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