Sensor arrangement with a plurality of potentiometric sensors

US7394263B2 · kind B2 · utility

Assignee

• Endress+Hauser Conducta Gesellschaft fuer Mess- und Regeltechnik mbH + Co. KG · DE

Inventors

• Torsten Pechstein · Radebeul, DE
• Wolfgang Babel · Linz, DE
• Thomas Steckenreiter · Frankfurt, DE

Key dates

• Filing date: Oct 28, 2004
• Grant date: Jul 1, 2008
• Expiry date: Oct 28, 2024

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/414
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The sensor arrangement includes: a least two sample chambers; at least two potentiometric FET-sensors, especially ISFET-sensors or ChemFET-sensors, having, in each case, a sensitive surface section, wherein each sensitive surface section lies in flow connection with its one of the sample chambers; and a reference cell having a reference medium for providing a reference potential, wherein the sample chambers are connected with the reference medium via an electrolyte bridge. The reference cell has, preferably, a potentiometric reference-FET-sensor for providing a reference potential, which is registered against the pseudo-reference-potential of a redox electrode. The potentials Udiff1, Udiff2, . . . UdiffN of N FET-sensors in the sample chambers are determined against the pseudo-reference-potential, and the measured-variable-relevant, potential differences are determined, in each case, by difference formation between the pertinent potential and the reference potential—thus, in the case of pH, according to the formulasUpH1. . . N=Udiff1. . . N−Udiffref.