Abstract:
A sensing apparatus (100) to measure nitric oxide (NO) in exhaled breath is disclosed. An embodiment of the sensing apparatus includes an inlet (102), a pretreatment element (104), and a sensing electrode(106). The inlet (102) is configured to receive the exhaled breath. The pretreatment element (104) is configured to receive the exhaled breath from the inlet (102) and to condition a chemical characteristic of the exhaled breath. The sensing electrode (106) is coupled to a chamber within the sensing apparatus (100). The chamber is configured to receive the pretreated exhaled breath from the pretreatment element (104). The sensing electrode (106) is configured to detect a component of nitrogen oxide (NOX) in the exhaled breath.
Abstract:
A method for detecting a gas phase constituent such as carbon monoxide, nitrogen dioxide, hydrogen, or hydrocarbons in a gas comprising oxygen such as air, includes providing a sensing material or film (20, 120) having a metal embedded in a catalytically active matrix such as gold embedded in a yttria stabilized zirconia (YSZ) matrix. The method may include annealing the sensing material at about 900°C, exposing the sensing material (20, 120) and gas to a temperature above 400°C, projecting light onto the sensing material (20, 120), and detecting a change in the absorption spectrum of the sensing material due to the exposure of the sensing material to the gas in air at the temperature which causes a chemical reaction in the sensing material compared to the absorption spectrum of the sensing material in the absence of the gas. Systems (700) employing such a method are also disclosed.
Abstract:
The invention relates to a method for measuring oxygen-containing nitrogen components, including nitrogen dioxide, in exhaust gases of internal combustion engines, in which method an exhaust gas sample is branched off from an extraction point 10 on the exhaust pipe 1 and is supplied by means of an extraction line 11 to at least one measuring device 5, wherein a separate extraction point 10 and extraction line 11 are provided for measuring the oxygen-containing nitrogen components, and in that, in order to measure the oxygen-containing nitrogen components, the exhaust gas sample is set to a temperature at which the possibility of a reaction between nitrogen dioxide and soot is low.
Abstract:
A photochemical sensing system enables the measurement of nitrogen oxides (nitrogen dioxide and nitric oxide) by photolyzing nitrogen dioxide to form oxygen atoms which combine with oxygen molecules to form ozone. Ozone reacts with nitric oxide to for nitrogen dioxide - decreasing ozone. Changes in ozone concentration are measured as a surrogate for the nitrogen dioxide and nitric oxide. Any species which photolyzes to yield oxygen atoms may be measured by this technique. Additional specificity for nitrogen oxides is conferred by allowing the nitric oxide to react with the ozone to recreate the nitrogen dioxide. By periodically photolyzing the nitrogen dioxide (to form ozone), and then allowing the resulting nitric oxide to react with the ozone (thereby reducing ozone), a pulsed signal is obtained whose amplitude is proportional to the total amount of nitrogen dioxide and nitric oxide present. Medical applications include measuring nitric oxide concentrations in expired air samples.
Abstract:
A computer- implemented system and method for converting the resistances of an array of metal oxide sensors into constituents and concentrations of a multi-component gas provided around the sensor array. The method includes providing a self-diagnostic module to calculate the quality factors associated with corresponding prediction models and determine if the response of the sensor array are within a preferrred range; and providing a concentration calculation module to calculate the gas concentration outputs from each prediction model, corresponding tolerance limits, and gas concentration outputs determined by weighting the outputs from the prediction models by corresponding quality factors and determining the weighted tolerance limits, so that the gas concentration outputs with the lowest tolerance limits can be reported as the actual constituents and concentrations of the multi-component gas .
Abstract:
Nitrogen-containing compounds are detected by chemically converting (210) them to nitrogen dioxide, and detecting (10) the amount of nitrogen dioxide. A semiconductor laser or light emitting diode (132) provides a modulated light (131) in the blue- violet-green wavelength range and a narrow bandwidth photo-acoustic sensor (10) detects the standing waves produced by the absorption of the light by the nitrogen dioxide. The photo-acoustic sensor (10) uses a resonant cavity (161, 182a-b) with a resonant frequency that corresponds to the modulation frequency of the light (131). For detecting nitric oxide, a surface chemical oxidation unit (210) is preferably used to convert the nitric oxide to nitrogen dioxide, using, for example potassium permanganate (KMnO4) filter, or a platinum (Pt) catalyst unit (260).
Abstract:
System for detection and analysis of gas samples in fieldable real-time Differential Mobility Spectrometry (DMS) chemical sensor system which uses non-radioactive ion source for monitoring and detecting NOx emissions; provides reliable methods for detecting and monitoring of anthropogenic sources of NOx; also detection of NO in exhaled breath for patient health diagnosis.
Abstract:
The invention concerns a handheld, small but accurate and reliable device for diagnostic NO measurements using a NO sensor, where the parameters governing the taking of the sample are different from the parameters optimal for the accuracy of said NO sensor. By temporarily storing a portion of the exhaled air, and feeding this to the sensor at a flow rate adapted to the NO sensor, the accuracy and sensitivity of a system / method involving NO sensors, in particular electrochemical NO sensors, can be increased. The method for diagnostic NO measurements comprises steps for controlling the inhalation of NO free air, as well as the exhalation, both by built-in means and by audible and/or visual feedback to the patient.
Abstract:
Es wird Sensorelement zur Bestimmung von Gaskomponenten in Gasgemischen, insbesondere von NO X in Abgasen von Verbrennungsmotoren, beschrieben mit einer ersten und einer zweiten elektrochemischen Konzentrationszelle. Die Konzentrationszellen weisen jeweils eine erste und eine zweite Elektrode (31, 33, 35) auf, wobei mit der ersten Konzentrationszelle freier Sauerstoff und mit der zweiten Konzentrationszelle die Summe aus freiem Sauerstoff und aus der Zersetzung der Gaskomponente resultierendem oder dabei verbrauchtem Sauerstoff bestimmt wird. Der ersten Elektrode (31) der ersten Konzentrationszelle ist ein Diffusionswiderstand (23) in Strömungsrichtung des Gasgemischs vorangestellt, der im wesentlichen einem der ersten Elektrode (33) der zweiten Konzentrationszelle vorangestellten Diffusionswiderstand (23) entspricht.
Abstract translation:有> X <内燃机的废气与第一和第二电化学浓差电池描述的传感器元件,用于确定在气体混合物的气体组分,特别是NO的。 细胞的浓度分别具有一个第一和一个第二电极(31,33,35),其中的游离氧,而从气体成分所得的分解或而消耗的氧与第一浓度的无细胞的氧和与所述第二浓度小区中确定的总和。 所述第二浓度细胞前缀扩散电阻(23)的第一电极(33)的第一浓度电池的第一电极(31)通过在气体混合物的流动方向基本上之一的扩散电阻器(23)之前。
Abstract:
A method of measuring a rate of change of carbon dioxide concentration in recirculated air of an engine, is disclosed. The method includes installing a conductive sample tube into an engine's pre-combustion/air-mixing chamber, and installing a carbon dioxide sensor, remote from the chamber, to measure relative concentrations of carbon dioxide. The method may also be used to measure nitrogen oxide exhaust gas levels.