Endress+hauser Conducta Gmbh+co. Kg

Jinshan Huo

Michael Hanko

Dennis Hui

Alden David

Hermann Günther

Thelma Saclot

Robert Tzschoppe

According to at least one aspect of the present disclosure, a method includes applying an alternating current having a frequency at a selected voltage to a sensor, wherein the voltage is applied between a reference electrode and a working electrode of the sensor, varying the frequency of the alternating current between a lower frequency and an upper frequency, measuring an impedance of the sensor between the reference electrode and the working electrode as a function of the frequency of the alternating current, analyzing the measured impedance to determine a total impedance of the sensor and the real and imaginary components of the total impedance at each applied frequency of the alternating current, and characterizing the sensor based on the total impedance at the low frequency end of the sensor and on the real and imaginary components of the total impedances.

Characterization and failure analysis of a sensor using impedance frequency response spectra

A method of and an apparatus for manufacturing a measuring cell comprising a tube having a first end capped by a membrane of an ion-selective material, comprising the steps of: providing a paste comprising all constituents of the ion-selective material; mounting the tube onto a stick with a tip such that the stick extends through the tube; dispensing an amount of the paste onto the tip; heating the first end of the tube and the dispensed paste to a temperature causing the dispensed paste to melt and the thus-produced melt to form a film covering the tip and an end surface of the first end of the tube; transforming the film into the membrane joined to the tube by cooling the first end of the tube and the film to a temperature below a melting point of the ion-selective material; and separating the thus-manufactured measuring cell from the stick.

Method of and apparatus for manufacturing at least one measuring cell

A method of manufacturing membranes consisting essentially of an ion-selective material is disclosed. The method comprises: providing a spreadable base material; dispensing a quantity of the base material onto a top side of a tray, wherein the top side includes a set of coplanar flat surface segments, each having a surface area corresponding to a disc area of one of the membranes to be manufactured, and wherein at least the top side of the tray consists essentially of a non-adhesive material; distributing the dispensed base material across the top side of the tray such that a thickness of the distributed base material covering the coplanar surface segments corresponds to a predetermined thickness; transforming the thus-distributed base material into ion-selective material comprising one or more coplanar sheets covering the coplanar surface segments; and removing individual membranes from the tray, each defining a disc-shaped section of the ion-selective material.

Method of manufacturing ion-selective membranes

According to at least one aspect of the present disclosure, a reference half-cell for an electrochemical sensor for measuring a medium is disclosed. The reference half-cell includes a housing defining a chamber containing an electrolyte, the housing including a wall having an aperture therethrough, and an electrode disposed in the electrolyte in the chamber. The reference half-cell further includes a reference junction disposed in the aperture such that an interface between the reference junction and the housing wall is impermeable. The reference junction is electrically or ionically conductive and impermeable to the measured medium and the electrolyte, and the reference junction enables a constant potential at the electrode. An electrochemical sensor and oxidation-reduction potential sensor employing the reference junction are also disclosed.

Sensor with nonporous reference junction

According to at least one aspect of the present disclosure, a method includes applying an alternating current at a selected voltage to a sensor, wherein the voltage is applied between a working electrode and/or reference electrode of the sensor and a temperature sensor integrated into the sensor, varying the frequency of the alternating current between a lower frequency and an upper frequency, measuring an impedance of the sensor between the working electrode and/or reference electrode and the temperature sensor as a function of the frequency of the alternating current, and determining whether, based on the total impedance at the low frequency end of the sensor and on the real and imaginary components of the impedance, the insulations between working electrode and/or reference electrode and temperature sensor have a defect.

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Corona, CA, United States of America

Jinshan Huo