Abstract: The present invention relates to an electrochemical gas sensor that includes a first planar substrate having at least one planar electrode formed thereon, thereby forming a first electrode assembly, and a housing defining a reservoir which, in use, contains liquid electrolyte for contacting the electrode(s). The housing has a first sealing face to which the first electrode assembly is sealed, the sealing face having conducting portions electrically isolated one from another. A portion of at least one electrode is in contact with a respective conducting portion so as to provide a means of external electrical connection to the electrode(s). The conductive portions and non-conductive portions of the housing are co-moulded. This sensor has a relatively small number of component parts and is relatively cheap and easy to manufacture. It also provides a cheap and reliable way of forming external electrical connections to the electrodes.

Abstract: The invention relates to a gas sensor and its method of manufacture. Electrochemical gas sensors usually comprise an external housing, which acts as a reservoir for electrolyte; a wick to keep electrodes wetted with the electrolyte and external electrical terminals, for making electrical contact with the electrodes. Typically a gas permeable/microporous membrane has been used to seal a gas sensor in order to prevent leakage of electrolyte. A problem with existing sensors has been that there was a risk of electrolyte leaking through the membrane around the region where electrical connectors passed therethrough. The present invention overcomes this by providing a method of urging conductive polymer through the membrane under controlled conditions of heat and pressure, thereby ensuring the integrity of the membrane remains in tact while defining an electrically/conductive pathway therethrough.

Abstract: Apparatus for sampling a liquid, said apparatus comprising: i) a sampling device capable of automatically taking a known volume of liquid from a source; ii) fixing means connected to said sampling device and removably attachable to a solid phase extraction (SPE) unit, the fixing means being arranged such that liquid taken from a sample by the sampling device is passed directly through the solid phase extraction unit; iii) a reading device able to read labels on an SPE unit attached to said fixing means; iv) a controller arranged to log codes based upon a signal from the reading device, and thereafter issue instructions to an operator and/or operate the sampling device to take an appropriate volume of liquid in response to a signal from said reading device. Methods of sampling using the apparatus are also claimed. These are useful in, for example analysis methods.

Abstract: A gas sensor including a housing containing at least a sensing electrode, a counter electrode, a test electrode, and electrolyte means in contact with such electrodes. The housing permits gas from the environment to flow to the sensing electrode. The gas sensor is operable either in a normal mode of operation in which potentials are applied to the electrodes for detecting when a gas to be sensed is present at the sensing electrode, or in a test mode of operation in which potentials are applied to the electrodes so that the test electrode generates a gas which flows to the sensing electrode to enable an indication whether the sensor is operating correctly.

Abstract: An electrochemical cell in the form of first and second sheet members (2,12) at least one of which is gas permeable on which is disposed one or more planar electrodes (4,6,8). Peripheral regions of the first and second sheet members (2,12) are sealed together to form a sealed envelope or reservoir containing electrolyte. Electrical connection means (41,61,81) extend from each of the electrodes (4,6,8) across the sealing of the sheet members (2,12) to provide external electrical connection.

Abstract: A gas sensor including a substrate that is porous at least in a region thereof to permit permeation of gas. At least first and second porous electrodes are formed as planar elements on the substrate. The substrate is bonded to a housing in a peripheral area of the sensor. A portion of the first electrode extends into this peripheral area and is rendered non-porous to prevent the leakage of electrolyte therethrough.