Smith-Hieftje Background Corrector

It will be remembered that the HCL functions by the creation of excited atoms that radiate at the desired resonance wavelengths. After radiating, the atoms form a cloud of neutral atoms that, unless removed, will absorb resonance radiation from other emitting atoms. 

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The Smith-Hieftje background corrector has taken advantage of this self-reversal phenomenon by pulsing the lamp, alternating between high current and low current. At low current, a normal resonance line is emitted and the sample undergoes normal atomic absorption. When the HCL is pulsed to a high current, the center of the emission... 

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