Sloping baseline compensation for a chromatographic analyzer
AssigneePhillips Petroleum Company
InventorLouis D. Kleiss
Life of this patent
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Abstract
A method and apparatus is disclosed for correcting errors in a chromatographic analysis wherein the trailing edge of a strong peak interferes with the integration of the trailing peak which follows the strong peak. In one embodiment of the invention two functions of the trailing peak are electrically integrated and summed to produce a correct peak integration. In a second embodiment of the invention the baseline is shifted and the integration of the trailing peak is performed with respect to the shifted baseline to produce a correct peak integration.
Claims8
Apparatus comprising:
- means for producing a first analog output signal having a varying voltage in time;
- a first integrating circuit adapted to integrate said first analog output signal over a period beginning at time t.sub.1 and ending at time t.sub.2 and adapted to establish a first signal representative of the results of the integration of said first analog output signal;
- means for establishing a second signal having a predetermined relationship to the difference between the voltage level of said first analog output signal at said time t.sub.1 and the voltage level of said first analog output signal at said time t.sub.2 ;
- and
- means for utilizing said second signal to shift the baseline used in the integration of said first analog output signal in such a manner that a correct integration of said first analog output signal may be performed even though the voltage level of said first analog output signal at said time t.sub.1 is not equal to the voltage level of said first analog output signal at said time t.sub.2.
A method for integrating a first analog output signal having a varying voltage in time comprising the steps of:
- integrating said first analog output signal over a period beginning at time t.sub.1 and ending at time t.sub.2 and establishing a first signal representative of the results of the integration of said first analog output signal;
- establishing a second signal having a predetermined relationship to the difference between the voltage level of said first analog output signal at said time t.sub.1 and the voltage level of said first analog output signal at said time t.sub.2 ;
- and
- utilizing said second signal to shift the baseline used in the integration of said first analog output signal in such a manner that a correct integration of said first analog output signal may be performed even though the voltage level of said first analog output signal at said time t.sub.1 is not equal to the voltage level of said first analog output signal at said time t.sub.2.
Dependencies are inferred from the claim text.