摘要:
A sensor for detecting a gas mixture which substantially comprises air and contains one or a plurality of gases that exhibit a disadvantageous effect on living organisms, comprising: a sensor chip composed of silicon for reading out at least one signal which is generated at a sensitive substance given the presence of one or a plurality of target gases in the measurement gas, a sensitive substance applied on the sensor chip, comprising living cells, which respond to target gas, a signal processing unit for evaluating the signals of the Si chip.
摘要:
A gas sensor based on a field effect transistor (“FET”) evaluates both a change in work function of a gas-sensitive layer of the FET and a change in the capacitance of the layer. Thus, two physically independent signals are read from the gas-sensitive layer, each signal representing a sensitivity to a different gas. This reduces the effect of cross-sensitivities; that is, of one gas on the target gas. The underlying physical mechanisms, the first causing a change in the work function in a reaction with gases and the second causing a change in the capacitance of the sensitive layer, are widely different. Because of this, the two parameters demonstrate different gas sensitivities. If the reactions to both gases are known, the effect of the interfering gas on the sensor signal can be compensated for, and with this the concentration of the target gas can be determined.
摘要:
A method for identifying people involves breathing respired air into a collector unit, trapping condensate from the respired air in the collector unit, introduction of the condensate by a same introduction to a DNA sensor unit, analysis of the condensate after a cell disruption, comparison of the result the data from a databank and output of the comparison result with analysis of the identity of a person.
摘要:
A FET gas sensor having a relatively low operating temperature, for example, room temperature, is free from cross sensitivities from interfering gases by a preceding in-line filter. The sensor's service life is substantially stabilizable by using fabric-like activated charcoal filters which can be regenerated by a moderate temperature increase, and by limiting the diffusion of the analyte gas, which is made possible by the relatively small amount of gas detectable on the sensitive layer of the sensor. This substantially increases the service life of the filters. The gas sensor eliminates cross sensitivities to thereby increase the detection reliability thereof. Also, the gas sensor has relative long term stability and is economical to build. The gas sensor can read relatively weak signals generated by gas-sensitive layers, for example, without other stronger gas signals interfering with the weak signals.
摘要:
A FET gas sensor having a relatively low operating temperature, for example, room temperature, is free from cross sensitivities from interfering gases by a preceding in-line filter. The sensor's service life is substantially stabilizable by using fabric-like activated charcoal filters which can be regenerated by a moderate temperature increase, and by limiting the diffusion of the analyte gas, which is made possible by the relatively small amount of gas detectable on the sensitive layer of the sensor. This substantially increases the service life of the filters. The gas sensor eliminates cross sensitivities to thereby increase the detection reliability thereof. Also, the gas sensor has relative long term stability and is economical to build. The gas sensor can read relatively weak signals generated by gas-sensitive layers, for example, without other stronger gas signals interfering with the weak signals.
摘要:
A gas sensitive field effect transistor comprises a semiconductor substrate that includes a capacitance well, and source and drain regions of a field effect transistor. A gate of the field effect transistor is separated from the semiconductor substrate by an insulator, and a gas sensitive layer separated from the gate by an air gap. The field effect transistor provides an output signal indicative of the presence of a target gas within the air gap to an amplifier, which provides an amplified output signal that is electrically coupled to the capacitance well.
摘要:
A gas-sensitive field-effect transistor (GasFET) for the detection or measurement of an amount of hydrogen sulfide present in ambient air includes a raised gate electrode and a transistor structure. The raised gate electrode may be formed from or coated with a gas-sensitive material such as tin oxide, or silver, silver oxide or mixtures thereof. An insulator layer may be disposed on top of the transistor structure. An air gap is formed between the gas-sensitive layer of the raised gate electrode and the insulator layer on top of the transistor structure.
摘要:
An ozone sensor has an ozone-sensitive layer containing an ozone-sensitive material which is encapsulated in a polymer or in a polymer mixture or is coated by at least one polymer or polymer mixture. Advantages result from a longer service life of the ozone-sensitive materials which, because of their high hygroscopic properties, would not be stable without encapsulation or coating. Furthermore, a polymer matrix can be selectively used as a filter or in order to eliminate interfering influences.
摘要:
Sensor for determining a chemical element and method for controlling such a sensor. The invention relates to a sensor (1) for determining a chemical element or a chemical compound (CO2) in a supplied gaseous medium with a reaction area (9), on and/or in which the element or the compound brings about a chemical reaction that changes a characteristic parameter (for example the work function), Version 3* of the reaction area (9), a sensor element (5) that is placed in the sensor (1) to detect the change in the characteristic parameter, a signal output (11) at which an output signal (UPS) corresponding to the chemical reaction detected by the sensor element can be detected as the measured variable, and a reaction control device (SC, 12) with an electrode system (10, 13) for applying a control voltage to affect a reaction in the reaction area (9). To be able to use the sensor more variably and more reliably, it is proposed to produce a surface topology of such dimensions that during operation, a moisture film (16) of deposited ambient moisture continuously coats the surface area of both the electrode system and the reaction area. Possibilities in particular are correction of long-term changes from the influence of surrounding gases, checking probe functionality, and selective adjustment to measure given chemical variables.
摘要:
A volumetric flow of an analyte, including exhaled air, is fed to a gas sensor unit by used of gas flow device, which can include various sensors for the determination of nitrogen oxides. An oxidation catalyst is used when using an NO2 sensor, which converts nitrogen monoxide to nitrogen dioxide and the gas sensor unit measures the content of nitrogen dioxide. The nitrogen monoxide content is calculated from the nitrogen dioxide content. In order to eliminate cross-sensitivity moisture and ethanol are also measured. The device can be applied to the determination of nitrogen monoxide content of exhaled air.