Alphasense Limited

Cambridge Enterprise Limited

John R Saffell

Elizabeth Jane Hodgkinson

Richard Smith

Darryl H Dawson

Peter Smith

Adam Meyer Boies

Patrick Timothy Moseley

Ralph Peter Tatam

Simone Hochgreb

Michael L Hitchman

Marlene Hossain

Darry H Dawson

Robert Nishida

Ronan Baron

John Davenport

Molybdenum oxide is doped with vanadium, nobidium, tantalum or titanium to form a stable MOtheta phase crystal structure as a vapor sensitive material for detecting vapors of volatile organic compounds. That material is used between electrodes connected to a measuring device to measure a change in an electrical quality in the presence of a vapor of a volatile organic compound. Concentration of the vapor is measured to low part per million ranges.

Highly effective sensor for the vapors of volatile organic compounds

The invention relates to an electrochemical gas sensing apparatus for sensing one or more analytes, such as NOand/or O, in a sample gas and a method of using same. The apparatus uses MnOas a filter for ozone. The MnOmay take the form of a powder which may be unmixed, mixed with various PTFE particles sizes, formed into a solid layer deposited onto a membrane and/or pretreated with NO.

Electrochemical gas sensor, filter and methods

Particle measurement apparatus comprises an inlet for receiving a gas sample for analysis, a photoionisation chamber, at least one light source arranged to illuminate an interior of the photoionisation chamber, first and second electrodes coupled to a power source and configured to provide a DC potential difference across at least a portion of the photoionisation chamber, and an outlet, together defining a gas flow path from the inlet, through the photoionisation chamber, and towards the outlet.

Particulate matter measurement apparatus and method

A gas analyzer and a corresponding method is provided to measure the concentration of formaldehyde within enclosed environments such as within buildings comprising an ultraviolet light source, a sample chamber, a detector. The detector measures the intensity of light received by photosensors within a measurement range of wavelengths, and at least one reference range of wavelengths. Advantageously, the concentration of formaldehyde is determined taking into account fluctuations in the intensity of light emitted by the light source, and in the presence of any interferents such as nitrogen dioxide.

Gas analyser

An optical absorption gas sensor comprising a body having an internal wall which defines a chamber, at least one aperture in the body through which a gas sample can enter the chamber, a light source, at least one reflector, a detector assembly which extends into the chamber and has a first side and an opposite second side, a detector which measures light which is incident at least a range of angles on at least a part of a first surface of the detector assembly on the first side of the detector assembly, wherein the light source is located within the chamber on the second side of the detector assembly, the whole being configured such that light from the light source passes through the gas sample and is reflected around the detector assembly, by the at least one reflector, onto the detector.

Optical absorption gas sensor

A dual gas sensor is described, having first and second working electrodes separated by a gas impermeable portion. The electrodes are preferably located on a gas permeable polymer support, with the gas impermeable portion being formed by compression of the permeable support. The sensor may also include one or more filters for location adjacent the electrodes to filter certain gases from the air. The preferred sensor is able to detect carbon monoxide and hydrogen sulfide. The sensor housing is formed with four connection pins, allowing a standard sensor housing to be used for dual sensors as well as single sensors having a dummy pin.

Electrochemical sensor

An electrochemical gas sensor comprises: a working electrode for exposure to a gas to be sensed; a counter electrode having an outer periphery; a reservoir for electrolyte; wick means providing a path for electrolyte to pass from the reservoir, around a first part or parts of the outer periphery of the counter electrode to provide electrolytic continuity between the counter electrode and the working electrode; and a gas diffusion means providing a path for gas to diffuse to or from a second part or parts of the outer periphery of the counter electrode.

Electrochemical gas sensor

Electrochemical sensor for determining analyte in the presence of interferent, particularly carbon monoxide in the presence of hydrogen. An electrochemical cell is designed so that current flow resulting from reference electrode potential shift caused by interferent cancels out the current flow caused by interferent at the working electrode. Another electrochemical cell corrects for interferent concentration using the potential difference between a reference electrode in contact with interferent and a referent electrode not affected by inteferent.

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Stoke Charity, United Kingdom

John R Saffell