Ngk Insulators, Inc.

Takao Murase

Nobuhide Kato

Yusuke Watanabe

Masashi Yasui

Tsunenori Yoshimura

Minoru Yokota

Rui Sakaguchi

Masao Kon

Yuji Katsuda

Tomonori Takahashi

Toshihiro Yoshida

Jun Usami

Noriyuki Ina

Shuichiro Oki

Motohiro Nishiwaki

Yasushi Watanabe

Norio Oshima

Junichiro Mizusaki

A heater section includes a plate-like ceramic body (a first substrate layer, a second substrate layer, and a third substrate layer) having a longitudinal direction (front-rear direction) and a short-length direction (left-right direction), and a heaterdisposed within the plate-like ceramic body and including a lead sectionand a heating sectionconnected to the lead section. The heating sectionincludes a straight portionextending along the longitudinal direction, and a lead side curved portionconnected to one of the ends of the straight portioncloser to the lead section. The lead side curved portionhas a lower resistance per unit length than the straight portionat one or more temperatures in the range of 700&#xb0; C. to 900&#xb0; C.

Ceramic heater, sensor element, and gas sensor

The heaterof the heater portion includes the linear portionsand the bend portions. A resistance value per unit length of the bend portionsat least at a temperature within a temperature range of no less than 700&#xb0; C. and no more than 900&#xb0; C. is lower than a resistance value per unit length of the linear portions

A gas sensorincludes a tubular protective coverhaving an element chambertherein and configured to allow a measured gas to flow from the outside into the element chamber; and a long sensor elementincluding a detecting portionlocated in the element chamberand configured to detect a specified gas concentration in the measured gas. An inclination angle &#x3b8;t of an axial direction of the sensor element(i.e., a direction parallel to an element axis A) in the element chamberwith respect to an axial direction of the protective cover(i.e., a direction parallel to a cover axis A) is 1&#xb0; or greater.

Gas sensor

A heating elementof a heater section includes an inner region, having a lower resistance per unit length than an outer regionat one or more temperatures in the range of 700&#xb0; C. to 900&#xb0; C.

A gas sensorincludes a tubular protective coverhaving an element chambertherein and configured to allow a measured gas to flow from the outside into the element chamber. The gas sensoralso includes a long sensor element, including a detecting portionlocated in the element chamberand configured to detect a specified gas concentration in the measured gas, and an insulatorhaving an inclined through-hole into which the sensor elementis inserted. An inclination angle &#x3b8;t of an axial direction of the sensor element(i.e., a direction parallel to an element axis A) in the element chamberwith respect to an axial direction of the protective cover(i.e., a direction parallel to a cover axis A) is 1&#xb0; or greater.

A heaterof a heater portion includes linear portionsand bend portions. A resistance value per unit length of the bend portionsat least at a temperature within a temperature range of no less than 700&#xb0; C. and no more than 900&#xb0; C. is lower than a resistance value per unit length of the linear portions

Provided is a gas sensor in which a protective cover has no looseness even by repetitive use. The gas sensor includes a sensor element for detecting a predetermined measurement target gas component in a measurement gas; a protective cover which protects a side of one end portion of the sensor element; and a housing which houses the sensor element. The protective cover includes a brim portion at one end portion of an outer surface of the protective cover. The brim portion is brought into contact with a contact surface provided in said housing, and is held between a swaging portion and the contact surface, the swaging portion extending from the contact surface while bending, so that the protective cover is fixed to the housing. The brim portion is tilted at a tilt angle of 5&#xb0; or more and 15&#xb0; or less relative to a plane vertical to a central axis of the gas sensor.

Gas sensor and gas sensor manufacturing method

A gas analyzer monitors concentration of discharged NOx even if an air ratio X is less than 1. The gas analyzer has three internal spaces and four electro-chemical pumps. The first space effects combustion of combustible gases and has a first pump to adjust oxygen partial pressure. The second space has a second pump to decrease oxygen partial pressure. The third space has a third electro-chemical pump to control oxygen partial pressure and a fourth pump to draw out oxygen generated when object gas is reduced or decomposed. An air introducing duct is provided so the outside pump electrodes of the first and second pumps are isolated and not directly exposed to object gas. This duct serves as oxygen source when oxygen is introduced into the first space. The gas analyzer has an operating section for operating the pumps, a calculating section, and a displaying/outputting section. A calibrating method is disclosed also.

Gas analyzer and method of calibrating the same

Provided is a CO sensor which comprises a solid electrolyte having oxygen ion conductivity and a standard electrode and a sensing electrode for measurement of carbon monoxide and at least one standard electrode and sensing electrode for measurement of at least one different gas other than carbon monoxide, especially sulfur dioxide, these electrodes being formed on at least a part of the surface of the solid electrolyte . This CO sensor is excellent in selectivity for carbon monoxide, can exclude the influence of the coexisting sulfur dioxide and oxygen on the carbon monoxide measured value, and, besides, can be used at high temperatures. A method for making the sensor and a method of using it are also provided.

Carbon monoxide sensor, method for making the same, and method of using the same

In a CO gas sensor composed of a CO gas sensing electrode,being made of Au or an Au alloy and a reference electrode,electrically connected to at least part of a surface of a solid electrolyte having an oxygen ion transfer property, which is superior in CO gas selectivity, in particular, reducing the affect of the co-existing oxygen to CO, and which works with a high precision at a high temperature, and in a CO gas measuring device using the gas sensor, the gas sensor being capable of determining a CO gas concentration by measuring a electromotive force change due to adsorption/oxidization of the carbon monoxide gas in the sensing electrode,when a constant current is caused to flow between the reference electrode,and the sensing electrode,or a current value caused by the oxidizing reaction of the carbon monoxide gas in the sensing electrode when a voltage is kept constant between the reference electrode,and the sensing electrode

Carbon monoxide gas sensor and measuring device using the same sensor

A sulfur dioxide gas sensor having a high selectivity of SO,gas, and an operability at a high temperature which comprises: a solid electrolyte having oxygen ion conductivity; a detecting electrode for measuring sulfur dioxide gas, electrically connected to at least a part of a surface of the solid electrolyte and containing glass and either gold or a gold alloy; and a basic electrode for measuring sulfur dioxide gas, electrically connected to at least a part of a surface of the solid electrolyte and containing Pt.

Sulfur dioxide gas sensor

A gas analyzer includes a gas sensor, a drive section that pumps oxygen in first to third processing zones of the gas sensor, an operating section that operates a pumping current flowing in a third electro-chemical pump cell into a gas value to be measured, a display output section that displays a value operated by the operating section, or outputs the value as an electrical output to the external, and a heater drive section that heats the gas sensor to a predetermined temperature.

Gas analyzer and method of calibrating said gas analyzer

Disclosed is a method and a sensing device capable of measuring a predetermined measurement gas component continuously and accurately with good response over a long period of time without being affected by a high oxygen concentration in a measurement gas. The measurement gas is introduced into a first processing zone. A first electrochemical pumping cell is used to lower a partial pressure of oxygen in an atmosphere thereof to a degree sufficient to control a partial pressure of oxygen in a subsequent second processing zone. The gas is introduced into the second processing zone. Oxygen in an atmosphere is pumped out by using a second electrochemical pumping cell so that the partial pressure of oxygen in the atmosphere is controlled to have a low value of partial pressure of oxygen which does not substantially affect measurement of an amount of the measurement gas component. The gas is introduced into a third processing zone. Oxygen produced by reducing or decomposing the measurement gas component is pumped out by using a third electrochemical pumping cell. The amount of the measurement gas component is determined from a detected value of a pumping current flowing through the third electrochemical pumping cell. The amount of the measurement gas component may be also determined by measuring an electromotive force by using an electrochemical sensor cell, in place of the third electrochemical pumping cell.

Growing community of inventors

Konan, Japan

Takao Murase