Orion Research, Inc.

Thermo Fisher Scientific Gmbh

Thermo Orion, Inc.

Thermo Fisher Scientific Aquasensors LLC

Xiaowen Wen

Steven J West

Hyoungsik Yim

Dawood Bhaijee

Fung Seto

Lori Hrdy

Moshe J Hirshberg

Arthur E Tobey

Armin B Kusig

Jonathan Lowe

John K Tsagatakis

Stephen Olsted

A method of measuring oxidant in an aqueous composition using an electrode system comprising a membrane permeable to a species to be measured, a cathode situated behind the membrane, and an electrolyte between the membrane and cathode. Embodiments of the method may include contacting the membrane and an anode with the aqueous composition, and measuring the current between the cathode and anode in response to a first voltage applied between them. A pulse of a second voltage may be applied between the cathode and the anode, where the second voltage is different from the first voltage. Apparatus and computer program products which may perform the method, are also provided.

Chlorine detection with pulsed amperometric detection

A low maintenance reference electrode has a liquid junction body with a multiplicity of micron-sized capillary channels extending through the body for transporting electrolyte to a test solution. A viscosity-increasing agent thickens the electrolyte to limit its flow to a rate on the order of microliters/day so that a few milliliters of electrolyte suffice to provide an extended electrode life.

Low maintenance reference electrode for electrochemical measurements

Temperature compensation for ion-selective electrodes is obtained by positioning a temperature-measuring element in a chamber of limited thermal mass which is in thermal contact with the measuring electrode filling solution but is thermally isolated from other filling solutions in the electrode. In a preferred embodiment, the temperature-measuring element comprises a thermistor enclosed within thin flexible tubing; the electrical leads of the thermistor are forced against a segment of the inner wall of the tubing by an elongated strand of material abutting the thermistor to enhance heat transfer with the thermistor.

Temperature compensation for ion-selective electrodes

A measurement/calibration cell for potentiometrically measuring ion concentration in a fluid interposes a barrier between measuring and reference electrodes and positions the measuring electrode at a sufficiently higher gravimetric potential above the reference electrode that seepage of electrolyte from the latter to the former is effectively precluded. A controller associated with the cell displays instructions and other desired information on a scrolling display such that a substantial amount of information can be presented in a relatively small display window.

Ion measurement/calibration cell

Described is a combination, PVC-membrane, Ion-Selective Electrode (ISE) with a replaceable sensing module and a single-junction, sleeve-type reference electrode. pH and ion-selective electrodes (ISEs) in the 'Combination' configuration, i.e., single probes containing both the sensing and reference half-cells, are more convenient, more economical, and can be used to analyze smaller samples than an equivalent pair of separate half-cell electrodes.

Combination ISE and solutions therefor

The present invention is a reagent which, when added as a conditioning solution to samples containing calcium and magnesium, selectively converts the calcium into a complex which does not interfere with magnesium ISEs, and thus allows accurate magnesium determinations by ISE in a wide variety of samples. The conditioning solution also eliminates strontium and barium interferences by the same mechanism, but these are of secondary importance because they occur in samples less frequently and because they interfere less severely. Also, the formulation of the reagent was optimized solely in order to eliminate calcium interference and its ability to remove strontium and barium interferences was surprisingly fortuitous.

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Lexington, MA, United States of America

Xiaowen Wen