摘要:
A gas sensor having a simple structure and capable of accurately measuring the combustible gas component concentration of a measurement gas such as an exhaust gas despite variations in the oxygen concentration of the exhaust gas and variations in element temperature. The gas sensor 1 has the following constituent features: (1) first processing space 9: a measurement gas is introduced thereinto via a first gas passage 11; (2) second processing space 10: a gas contained in the first processing space 9 is introduced thereinto via a second gas passage 13; (3) oxygen concentration detection element 4: adapted to measure the oxygen concentration of a gas contained in the first processing space 9; (4) oxygen pumping element 3: adapted to reduce the oxygen concentration of the measurement gas introduced into the first processing space 9 within a range such that water vapor contained in the measurement gas is not substantially decomposed; (5) oxidation catalyst section 16: adapted to accelerate combustion of a combustible gas component contained in a gas introduced into the second processing space 10; and (6) combustible gas component concentration detection element 5: a constant voltage is applied thereto, and element 5 has an output current which varies according to the amount of oxygen consumed by combustion of a combustible gas component contained in the gas introduced into the second processing space 10 from the first processing space, to thereby provide information regarding the concentration of the combustible gas component of the measurement gas based on the output current.
摘要:
[Objective] To provide a gas sensor which can improve the sensitivity to NO x . [Means for Solution] A reduction section 18 for reducing NO 2 contained in exhaust gas to NO is provided on the upstream side of a first diffusion resistor section 103 provided to limit the flow of the exhaust gas into a first measurement chamber 101. When NO x passes through the first diffusion resistor section 103, NO 2 which is greater in molecular weight than NO is lower in the degree of diffusion than NO. Since NO 2 is reduced to NO at the reduction section 18, the exhaust gas passing through the first diffusion resistor section 103 hardly contains NO 2 . Therefore, the speed of flow of NO x through the first diffusion resistor section 103 is not limited by NO 2 , whereby sensitivity for detection of NO x can be improved.
摘要翻译:[目的]提供一种可提高对NOx的灵敏度的气体传感器。 [解决手段]在第一扩散阻力部103的上游侧,设置用于将废气中所含的NO 2还原为NO的还原部18,该第一扩散阻滞部103设置成限制废气向第一测定室101内的流动。 通过第一扩散电阻部分103,分子量大于NO的NO2的扩散程度低于NO。 NO 2在还原部18被还原成NO,因此通过第一扩散阻力部103的排气几乎不含有NO 2。 因此,通过第一扩散电阻部103的NOx的流动速度不受NO2的限制,由此可以提高用于检测NOx的灵敏度。
摘要:
A gas sensor having a simple structure and capable of accurately measuring the combustible gas component concentration of a measurement gas such as an exhaust gas despite variations in the oxygen concentration of the exhaust gas and variations in element temperature. The gas sensor 1 has the following constituent features: (1) first processing space 9: a measurement gas is introduced thereinto via a first gas passage 11; (2) second processing space 10: a gas contained in the first processing space 9 is introduced thereinto via a second gas passage 13; (3) oxygen concentration detection element 4: adapted to measure the oxygen concentration of a gas contained in the first processing space 9; (4) oxygen pumping element 3: adapted to reduce the oxygen concentration of the measurement gas introduced into the first processing space 9 within a range such that water vapor contained in the measurement gas is not substantially decomposed; (5) oxidation catalyst section 16: adapted to accelerate combustion of a combustible gas component contained in a gas introduced into the second processing space 10; and (6) combustible gas component concentration detection element 5: a constant voltage is applied thereto, and element 5 has an output current which varies according to the amount of oxygen consumed by combustion of a combustible gas component contained in the gas introduced into the second processing space 10 from the first processing space, to thereby provide information regarding the concentration of the combustible gas component of the measurement gas based on the output current.
摘要:
A NOx sensor includes a sensor element equipped with first and second pumping cells to define first and second measurement chambers. The first pumping cell exerts an oxygen pumping action against the first measurement chamber to adjust the oxygen concentration in the gas under measurement within the first measurement chamber to a given level. The second pumping cell exerts an oxygen pumping action against the second measurement chamber to produce a pumping cell current according to the NOx concentration in the gas under measurement. When the moisture content of the gas under measurement changes from 2 vol% to 8 vol%, the NOx sensor allows a variation of NOx concentration detection value based on the pumping cell current in such a manner that the NOx concentration detection value reaches a transient peak value of 20 ppm, or smaller and converges to ± 5 ppm of a reference value within 5 seconds. Also a method of production of said sensor is disclosed.
摘要:
A NOx sensor includes a sensor element equipped with first and second pumping cells to define first and second measurement chambers. The first pumping cell exerts an oxygen pumping action against the first measurement chamber to adjust the oxygen concentration in the gas under measurement within the first measurement chamber to a given level. The second pumping cell exerts an oxygen pumping action against the second measurement chamber to produce a pumping cell current according to the NOx concentration in the gas under measurement. When the moisture content of the gas under measurement changes from 2 vol% to 8 vol%, the NOx sensor allows a variation of NOx concentration detection value based on the pumping cell current in such a manner that the NOx concentration detection value reaches a transient peak value of 20 ppm, or smaller and converges to ± 5 ppm of a reference value within 5 seconds. Also a method of production of said sensor is disclosed.
摘要:
[Objective] To provide a gas sensor which can improve the sensitivity to NO x . [Means for Solution] A reduction section 18 for reducing NO 2 contained in exhaust gas to NO is provided on the upstream side of a first diffusion resistor section 103 provided to limit the flow of the exhaust gas into a first measurement chamber 101. When NO x passes through the first diffusion resistor section 103, NO 2 which is greater in molecular weight than NO is lower in the degree of diffusion than NO. Since NO 2 is reduced to NO at the reduction section 18, the exhaust gas passing through the first diffusion resistor section 103 hardly contains NO 2 . Therefore, the speed of flow of NO x through the first diffusion resistor section 103 is not limited by NO 2 , whereby sensitivity for detection of NO x can be improved.
摘要:
An apparatus and method for individually detecting NO and NO 2 concentrations as NO X components of an object gas. An NO concentration corresponding value is obtained from a first detection element not having a reduction section. An NO concentration corresponding value is obtained from a second detection element having a reduction section, and having an NO 2 /NO sensitivity ratio greater than that of the first detection element. The difference ”C between the NO concentration corresponding values of the two detection elements is obtained, and divided by the difference ”S between the NO 2 /NO sensitivity ratios of the two detection elements, whereby an NO 2 concentration corresponding value is obtained. A value obtained by multiplying the NO 2 concentration corresponding value by the NO 2 /NO sensitivity ratio of the second detection element is subtracted from the NO concentration corresponding value of the second detection element, whereby an NO concentration corresponding value is obtained.
摘要:
An apparatus and method for individually detecting NO and NO 2 concentrations as NO X components of an object gas. An NO concentration corresponding value is obtained from a first detection element not having a reduction section. An NO concentration corresponding value is obtained from a second detection element having a reduction section, and having an NO 2 /NO sensitivity ratio greater than that of the first detection element. The difference ΔC between the NO concentration corresponding values of the two detection elements is obtained, and divided by the difference ΔS between the NO 2 /NO sensitivity ratios of the two detection elements, whereby an NO 2 concentration corresponding value is obtained. A value obtained by multiplying the NO 2 concentration corresponding value by the NO 2 /NO sensitivity ratio of the second detection element is subtracted from the NO concentration corresponding value of the second detection element, whereby an NO concentration corresponding value is obtained.