×

System for measuring the concentration of chemical substances

  • US 4,397,714 A
  • Filed: 06/16/1980
  • Issued: 08/09/1983
  • Est. Priority Date: 06/16/1980
  • Status: Expired due to Term
First Claim
Patent Images

1. In a transducer system for detecting chemical properties of substances and including a semiconductor substrate having a doping polarity, a pair of spaced-apart diffusion regions located at the surface of the substrate and having doping polarity opposite that of said substrate material, an electrical insulator material overlying at least a portion of said diffusion regions and the surface of the substrate lying between the diffusion regions, a chemical selective system including a chemical selective membrane disposed over at least a portion of said insulator material, and a reference electrode connected in circuit with said spaced apart diffusion regions through a potential source, the combination thereof withan electrical conductive material disposed between the substrate and diffusion regions and the chemical selective membrane so as to be located above at least a portion of the substrate which is between the diffusion regions,a first switch element coupled to the conductive material and operable to selectively connect the conductive material to a voltage source, anda second switch element coupled to the conductive material and operable to selectively connect the conductive material to a ground potential source.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×