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:
Oct. 30, 1979
Filed:
Mar. 13, 1978
Howard R Branch, Northfield, CT (US);
American Chain & Cable Company, Inc., Bridgeport, CT (US);
Abstract
The voltage drops across a series-connected pair of strain gauges and arbitrary resistance are measured at zero and maximum stresses at three temperatures. The appropriate resistance for span compensation at the two extreme temperatures is then calculated from these values. The span compensation resistance is then distributed between a first resistor connected in series with one of the strain gauges and a second resistor connected in series with the other strain gauge. Initially, the first resistor is assigned a value of one ohm and the second resistor the remainder. With these values the series/parallel resistances required for temperature compensation at zero stress are calculated for the two extreme temperatures. The outputs at zero stress are then calculated for both the maximum temperature and the intermediate temperature and the difference between these outputs is obtained. Next, the resistance of the first resistor is increased by one ohm and the series/parallel resistances required for temperature compensation are again calculated for the extreme temperatures. From these values the outputs at zero stress are calculated for both the maximum and intermediate temperatures. The difference between these outputs is then compared with the difference previously calculated, and whichever value is closer to zero is retained along with the necessary circuit parameters. This process is repeated for each value of the first resistor less than the span resistance, so that the retained circuit parameters define the resistance values which produce the best three-point temperature compensation.