Abstract: The invention concerns an automatic continuous-flow fluid analyzer of the pe wherein a stream of fluid, segmented by air bubbles or other separating medium inert to the fluid to be analyzed, passes through a colorimeter flow cell. The bubble artifact is eliminated from the photoconductor signal while allowing the signal produced from the fluid segment to remain intact. This is accomplished by means of a signal comparator which operates as a digitally controlled differentiator, but could alternatively be a purely analog differentiator. The signal comparator through continual signal comparisons momentarily samples and stores a photoconductor output.For a finite period of time, the stored value is compared with all subsequent succeeding photoconductor output signals. If any signal that follows varies outside a preset range from the stored value, the comparator logic concludes that an air bubble is passing and the output to the recorder is not changed.
Type:
Grant
Filed:
January 14, 1975
Date of Patent:
June 8, 1976
Assignee:
The United States of America as represented by the Secretary of the Army
Inventors:
William E. Neeley, Stephen C. Wardlaw, Maurice E. T. Swinnen