Abstract:
The invention relates to a measuring device for measuring the diffusion of a gaseous substance on the surface of a material (8), which measuring device includes a body (1), in which there is a first contact surface and a second contact surface, as well as an internal space (7) between the first and the second contact surface, and which first contact surface is arranged to be placed against the surface (9) of the material (8) being measured, in order to create a diffusion flow between the material (8) being measured and the diffusion path in the internal space (7), and at least one content sensor (5) for measuring the content, for example, the vapour pressure, of the gaseous substance, at a content measuring point located in the diffusion path. The measuring device according to the invention is equipped with means (20) for resisting the diffusion of the gaseous substance in the diffusion path, between the content measuring point and the second contact surface of the body (1). Thus, the diffusion path can be designed to be extremely short, without essentially reducing the accuracy of the measurement, in which case the stabilization of the content profile is accelerated considerably.
Abstract:
A process is provided for determining the amount of sulfuryl fluoride in the atmosphere of an enclosed area that has been fumigated with sulfuryl fluoride (SO 2 F 2 ). This process comprises: (A) sampling said atmosphere of said enclosed area to obtain a gaseous sample; (B) selectively removing water from said gaseous sample by passing said gaseous sample through a perevaporation zone to obtain a perevaporated sample, wherein said perevaporation zone comprises a copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid; and (C) analyzing said perevaporated sample in a sulfuryl fluoride detector to determine the amount of sulfuryl fluoride in said perevaporated sample.
Abstract:
The invention relates to a method and a device for continually and especially quickly detecting changes in the concentration of radon gas by means of conversion into a measuring gas (Rn-222) which can be used for varied monitoring, controlling and regulating tasks, whereby said gas is dissolved in water. A membrane is permeable to the radioactive noble gas radon but is essentially impermeable to water. The invention is based upon said membrane being flown round by the radon-containing water on the one side and by a carrier gas on the other side in parallel or in opposite directions and involving flow rates which are optimised respectively. The concentration of radon in the measuring gas is directly proportional to the concentration of radon in water when stable marginal conditions are guaranteed.
Abstract:
A device for continuous extraction and analysis of one or more substances in a source of analytes has a membrane located in a funnel shaped housing. The housing receives the source of analytes so that the analytes are separated from the membrane by a headspace. The headspace can be agitated and the housing can contain a purger to fill the headspace with inert gas. Extracting fluid is passed on one side of the membrane to carry analytes that pass through the membrane to a sorbing phase where the concentration of the substances are increased. No chemicals are added and the extracting fluid is passed to an analysis device for analyzing the analytes.
Abstract:
A gas measurement device for measuring at least one gas in the stomach of a mammal, the device comprises a housing for being located in the mammal's stomach and providing at least one gas sensor for detecting the gas. The housing is impermeable to liquid within the stomach. The device may also comprise a controller disposed within the housing and which is electrically coupled to the at least one gas sensor. The controller is arranged to periodically process an output from the gas sensor(s) to provide data indicative of the amount of the gas within the stomach. The controller can include a wireless transmitter for transmitting the data to a remotely located receiving device disposed exterior to the mammal.
Abstract:
Proceso analítico de separación de especies volátiles de aplicación a muestras líquidas, sólidas o mezcla de ambas, caracterizado por la hibridación de los procesos implicados en las técnicas de espacio de cabeza dinámico y perevaporación analítica, así como el diseño de un módulo básico para llevar a cabo dicha separación analítica.
Abstract:
Apparatus for chemical detection includes a cap (12) for coupling with a sample vial (20) containing a sample. The sample includes at least one chemical to be detected. The cap (12) includes a reagent vial (14) which contains a liquid reagent. The reagent vial includes a membrane (15) which substantially retains the liquid reagent and which is substantially permeable to the chemical to be detected. The reagent vial (14) can be opened to allow the chemical to permeate the membrane (15) and enter the reagent vial (14) and closed to substantially prevent the chemical from permeating the membrane (15) and entering the reagent vial. In some embodiments, the reagent vial is opened and closed by movement of the reagent vial. In some other embodiments, the reagent vial remains stationary while a device moves to open and close the stationary reagent vial.
Abstract:
Carbon dioxide levels in an open-container beverage are measured by transferring a quantity of the beverage to a vessel. A closure is secured onto the vessel to form an enclosed volume containing the beverage. A probe is inserted through the closure to contact the beverage, and a sample is transferred from the vessel to a measurement instrument to determine the carbon dioxide level. The methods allow for significantly greater precision and reliability in measuring carbonation levels of open-container beverages relative to currently available techniques.
Abstract:
An improved tube probe for measuring volatile compounds in a liquid or gas contained in a reactor or in any other environment is disclosed as are improved gas detecting mechanisms. The probe is made of a single piece of metal (10), to one end of which is attached a gas permeable tubing (26), threaded on a supporting plate (28). The plate permits to use of a variety of tube lengths and diameters while protecting the tube from mechanical stress due to agitation and aeration. Furthermore, the plate gives the possibility to have a longer permeable tube than the single loop probe approach. The probe is designed so that when in use, substantially only the tube is located inside the reactor. The volatile compounds permeate into the tube into the carrier gas and the carrier gas + volatiles mixture is carried to a detector through a channel provided in the probe body. Novel electrical circuits to operate a gas sensing element are also disclosed.
Abstract:
Ölgekühlte Transformatoren werden häufig mit einer Messkammer (1) für auftretenden Wasserstoff überwacht, da der Wasserstoff ein Indikator für in dem Trafoöl gelöste Crackprodukte ist. Der Wasserstoff kann dabei über eine gasdurchlässige Membran von der Transformatorkammer (2) in die Messkammer (1) diffundieren. Bei einer Leckage kann jedoch auch Trafoöl (11) einbrechen, was unter anderem zu Fehlmessungen führen kann. Erfindungsgemäss wird daher der Gassensor (10) der Messkammer (1) derart angeordnet, dass er bei einem Öleinbruch wenigstens teilweise in das Öl eintaucht und dadurch den Öleinbruch detektieren kann. In weiterer Ausgestaltung der Erfindung wird die Messgenauigkeit durch eine Heizeinrichtung (7) im Bereich der Membran (3) verbessert. Auch ist ein Verschlusskörper (82) für austretendes Trafoöl vorsehbar.