The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 25, 1990
Filed:
Jul. 12, 1988
Richard S Willing, Granada Hills, CA (US);
Baxter International Inc., Deerfield, IL (US);
Abstract
A parameter measuring apparatus includes a constant signal circuit incorporating a sensor having a known response to a given parameter for outputting a signal representing the parameter. The constant signal circuit further includes circuitry defining upper and lower limits of the parameter range. The parameter signal is provided to a sampling device such as current-to-frequency converter for providing an analog-to-pulse converted signal to a microprocessor. The apparatus further includes a switching arrangement coupled to and controlled by the microprocessor for switching into circuit the sensor or the circuitry defining the upper or lower parameter limits. The switching arrangement also eliminates internal switch resistance in the circuit for improved measurement accuracy. With the known response of the sensor as well as known regression analysis correction calculations stored in the microprocessor, the microprocessor outputs a corrected parameter signal which accurately represents the measured parameter regardless of variation in circuit operation due to changes in operating conditions.