Quasi-simultaneous measurement of line and

Alternative measurements of the absorption of the hollow cathode lamp radiation and of the radiation of the continuum source can also be taken in a rapidly alternating mode, and accordingly a quasi-simultaneous measurement of line and background absorption, as required with transient signals, becomes possible. This can be realized by a rotating mirror and is sufficiently rapid to enable a high time resolution, as shown by Berndt et al. [305]. 

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