Reader recorder for toxic gas concentration tapes
AssigneeMDA Scientific, Inc.
InventorsRame Bull, Byron A. Denenberg, Djorde R. Popovic
Life of this patent
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Abstract
A reader recorder which will plot a concentration versus time graph based on stain intensity of a gas sensitive tape. Simultaneously, the device will integrate the area under the curve to obtain the total dosage for the period of time covered by the graph. By means of a common drive system for the recorder and the tape drive a meaningful relationship between displacement on the tape and position on the graph is obtained yielding information on the exact time of occurrence of events of interest.
Claims9
A reader recorder device for producing a graph of gas concentration versus time and of total dosage from a portion of gas sensitive tape exposed over a known time period, said device comprising:
- (a) means for reading said gas sensitive tape at a first rate to produce a time varying voltage corresponding to said gas concentration,
- (b) means for linearizing the relationship between gas concentration and said varying voltage.
- (c) integrator means for performing a voltage versus time integration of the linearized voltage to obtain an electrical signal having a magnitude representative of the area under the graph of said time varying voltage over said known time period, said electrical signal representing said total dosage,
- (d) means for recording on chart paper at a second rate said variation in voltage with respect to time and said total dosage, the relationship between the first and second rates permitting a determination of the time of occurrence of a gas concentration change of interest.
Dependencies are inferred from the claim text.