Abstract: A particulate measurement system measures the amount of particulates when at least one or a plurality of three operating condition parameters selected from speed of the vehicle, rotational speed of the internal combustion engine and torque of the internal combustion engine fall within previously set respective ranges, and the particulate measurement system does not measure the amount of particulates or invalidates the result of measurement of the amount of particulates when the one or plurality of operating condition parameters do not fall within the previously set respective ranges.

Abstract: A particulate amount determination section of a particulate measurement system corrects a measurement signal or the amount of particulates determined from the measurement signal based on one or a plurality of three operating condition parameters selected from speed of the vehicle, rotational speed of the internal combustion engine and torque of the internal combustion engine.

Abstract: A particulate sensor including a sensor unit (300) having an ion generation section (611, 361, 322); an electric charge section (612) for electrically charging at least portion of particulates S using ions PI; a capture section (616, 617, 316, 326, 362) for trapping at least portion of the ions PI not used for electrically charging the particulates S; and a sensor ground section (340, 310v, 330v3) connected to the capture section and having a first floating potential corresponding to the amount of the ions PI trapped by the capture section. The sensor unit can detect the amount of the particulates S in the gas on the basis of the electric potential of the sensor ground section. The sensor ground section is covered with insulating ceramic at that outer portion of the sensor unit which comes into contact with the gas.

Abstract: A particulate detection system (1) for detecting the amount of particulates S in a gas under measurement EG includes a detection section (10), a drive circuit (210, 240), and a drive control section (225). The detection section includes a first potential member (31, 12, 13) maintained at a first potential PV1, a second potential member (14, 51, 53) maintained at a second potential PVE, PV3, and an insulating member (121, 77, 76) disposed between the first and second potential members. The system includes insulation test means (215, S3, 245, S5) for testing the degree of insulation between the first and second potential members. The drive control section includes drive permission/prohibition determination means S4, S6 for determining, on the basis of the degree of insulation tested by the insulation test means, whether to permit the drive of the detection section by the drive circuit.

Abstract: There is provided a fine particle detection system with a fine particle sensor, a cable and a sensor drive control device. The fine particle sensor has an ion source unit with first and second electrodes, a particle charging unit and inner and outer sensor casings. The cable has a power supply wiring line connected to the second electrode, an inner shield line electrically continuous with the inner sensor casing and an outer shield line electrically continuous with the outer sensor casing. The sensor drive control device has an ion-source power supply circuit, a signal current detection circuit, an inner circuit casing electrically continuous with a first output terminal of the ion-source power supply circuit and surrounding the ion-source power supply circuit and an outer circuit casing connected to the ground potential and shielding the ion-source power supply circuit, the signal current detection circuit and the inner circuit casing.

Abstract: There is provided a fine particle sensor for detecting fine particles in exhaust gas, including an ion generating unit for generating ions by corona discharge, a charging unit for charging the fine particles by some of the generated ions, an ion trapping unit for trapping a remainder of the generated ions and a casing for accommodating therein the charging unit and the ion trapping unit in a given arrangement direction. The casing has a gas inlet hole and a gas outlet hole formed in a circumferential wall thereof so that the exhaust gas flows in the charging unit through the gas inlet hole and flows out of the ion trapping unit through the gas outlet hole. The gas inlet hole and the gas outlet hole are arranged in such a manner as to at least partially overlap each other when viewed in the given arrangement direction.

Abstract: A thin plate member which has a groove portion recessed toward the inside in a radial direction with a gap interposed between the thin plate member and the outer surface of a site on the front end side of a main body section. At least one end of the thin plate member is joined to the outer surface of the main body section and is provided radially outside the site on the front end side of the main body section. A seal member is disposed in the groove portion and has elasticity due to resin. Since the gap functions as a heat-insulating layer and is interposed between the seal member and the main body section, heat conduction from the main body section, that is, heat conduction through a first pathway is reduced, and thus deterioration of the seal member due to heat is suppressed.

Abstract: There is provided a fine particle detection system with a fine particle sensor, a cable and a sensor drive control device. The fine particle sensor has an ion source unit with first and second electrodes, a particle charging unit and inner and outer sensor casings. The cable has a power supply wiring line connected to the second electrode, an inner shield line electrically continuous with the inner sensor casing and an outer shield line electrically continuous with the outer sensor casing. The sensor drive control device has an ion-source power supply circuit, a signal current detection circuit, an inner circuit casing electrically continuous with a first output terminal of the ion-source power supply circuit and surrounding the ion-source power supply circuit and an outer circuit casing connected to the ground potential and shielding the ion-source power supply circuit, the signal current detection circuit and the inner circuit casing.

Abstract: There is provided a fine particle sensor for detecting fine particles in exhaust gas, including an ion generating unit for generating ions by corona discharge, a charging unit for charging the fine particles by some of the generated ions, an ion trapping ions for trapping a remainder of the generated ions and a casing for accommodating therein the charging unit and the ion trapping unit in a given arrangement direction. The casing has a gas inlet hole and a gas outlet hole formed in a circumferential wall thereof so that the exhaust gas flows in the charging unit through the gas inlet hole and flows out of the ion trapping unit through the gas outlet hole. The gas inlet hole and the gas outlet hole are arranged in such a manner as to at least partially overlap each other when viewed in the given arrangement direction.

Abstract: It is an object of the invention to provide a gas detecting device capable of relieving the influence of an environment such as a temperature, a humidity or a wind velocity to detect a change in a concentration of a specific gas and an autoventilation system for a vehicle using the gas detecting device. More specifically, a gas detecting device (10) using a gas sensor element (11) changing a sensor resistance Rs depending on a concentration of a gas such as NOx and an autoventilation system (100) for a vehicle according to the invention A/D convert the output of a sensor resistance value converting circuit (14) to acquire a sensor output value S(n), calculates a base value B(n) based on B(n)=B(n?1)+k1{S(n)?B(n?1)}, and furthermore, calculates a difference value of D(n)=S(n)?B(n).

Abstract: A gas detection apparatus incorporating a gas sensor element and a vehicle automatic ventilation system including the apparatus in which a sensor output value S(n) is obtained, and a base value B(n) is calculated by use of Expression (1): B(n)=B(n?1)+k1[S(n)?B(n?1)]?k2[S(n)?S(n?5)] in the case where S(n)?B(n?1), or by use of Expression (3): B(n)=S(n) in the case where S(n)<B(n?1), followed by calculation of a difference value D(n); i.e., S(n)?B(n). When the difference value exceeds a predetermined high connection threshold, a high-concentration signal is generated to close a flap. After that, the base value B(n) is calculated by use of Expression (4): B(n)=B(n?1)+k3[S(n)?B(n?1)]?k4[S(n)?S(n?5)]. When the difference value becomes smaller than a predetermined low-concentration threshold, a low-concentration signal is generated to open the flap.

Abstract: A control system for a gas sensor element capable of lessening the effect of variations in sensor properties among gas sensor elements as well as the effect of environmental factors, such as temperature and humidity, to thereby accurately detect variation in the concentration of a specific gas. In a control system 10 for a gas sensor element 11 whose sensor resistance Rs varies with the concentration of NOx gas, a pulse signal Sc which alternates between 0 V and +5 V is input to a pulse input terminal 17. When a voltage of 5 V is applied to the pulse input terminal 17, a capacitor 14 is charged via a fixed resistor 15 having a resistance Rc and a diode 16. When a voltage of 0 V is applied, the capacitor 14 discharges via the gas sensor element 11. An output voltage Vout is A/D-converted and processed by means of a microcomputer 20, thereby controlling an electronic control assembly 21.

Abstract: A gas detection apparatus incorporating a gas sensor element and a vehicle automatic ventilation system including the apparatus in which a sensor output value S(n) is obtained, and a base value B(n) is calculated by use of Expression (1): B(n)=B(n−1)+k1[S(n)−B(n−1)]−k2[S(n)−S(n−1)] in the case where S(n)≧B(n−1), or by use of Expression (2): B(n)=S(n) in the case where S(n)<B(n−1), followed by calculation of a difference value D(n); i.e., S(n)−B(n). When the difference value exceeds a predetermined concentration threshold, a high-concentration signal is generated to close a flap. After that, the base value B(n) is calculated by use of Expression (5): B(n)=B(n−1)+k3[S(n)−B(n−1)]−k4[S(n)−S(n−1)]. When the difference value becomes smaller than a predetermined concentration threshold, a low-concentration signal is generated to open the flap.

Abstract: It is an object of the invention to provide a gas detecting device capable of relieving the influence of an environment such as a temperature, a humidity or a wind velocity to detect a change in a concentration of a specific gas and an autoventilation system for a vehicle using the gas detecting device.

Abstract: A control system for a gas sensor element capable of lessening the effect of variations in sensor properties among gas sensor elements as well as the effect of environmental factors, such as temperature and humidity, to thereby accurately detect variation in the concentration of a specific gas. In a control system 10 for a gas sensor element 11 whose sensor resistance Rs varies with the concentration of NOx gas, a pulse signal Sc which alternates between 0 V and +5 V is input to a pulse input terminal 17. When a voltage of 5 V is applied to the pulse input terminal 17, a capacitor 14 is charged via a fixed resistor 15 having a resistance Rc and a diode 16. When a voltage of 0 V is applied, the capacitor 14 discharges via the gas sensor element 11. An output voltage Vout is A/D-converted and processed by means of a microcomputer 20, thereby controlling an electronic control assembly 21.

Abstract: A constant current Iconst is applied to an electromotive force cell which is interposed between a gap (measurement chamber) of a fixed atmosphere and an oxygen reference chamber of a constant oxygen content, for measurement of a resistance value of the electromotive force cell, whereby the resistance value can be measured accurately irrespective of an oxygen content in an atmosphere to be measured by an oxygen sensor element or cell unit. The resistance value of the electromotive force cell is measured at a predetermined timing T2 after application of a current is started, so that a measure resistance value is free of a variation of a resistance value due to deterioration of porous electrodes of an electromotive force cell, such a variation being included in the measured resistance value in case the measurement is done by using an AC current, and therefore accurate measurement can be attained.

Abstract: A method of detecting a deteriorated condition of a wide range air-fuel ratio sensor is provided. Firstly, a current is applied to an electromotive force cell to detect a voltage Vs0 across electrodes on opposite side surfaces of the cell. Application of the current is suspended, and a voltage drop Vsd1 across the electrodes is detected after lapse of a time ranging from 10 .mu.s to 1 ms after the application of the current is suspended. Based on the voltage drop Vsd1 is detected a first resistance value Rvs1 equated to the temperature of the electromotive force cell. Further, after lapse of a time ranging from 10 ms to 50 ms after the application of the current to the electromotive force cell is suspended, a voltage drop Vsd2 across the electrodes of the electromotive force cell is detected. Based on the voltage drop Vsd2 is detected a second resistance value Rvs2 equated to an internal resistance of the electromotive force cell including a resistance component resulting from deterioration.

Abstract: A method of detecting an activated condition of a wide range air-fuel ratio sensor is provided. With this method, application of a current to a heater is started idiately after an engine is started (S00). Then, a current Icp for pumping is passed through an electromotive force cell (S10). A lapse of a predetermined time Tin is waited for (S18). After a lapse of time Tin, a voltage Vs across both electrodes of the electromotive force cell is detected (S20) and labeled as Vs0 (S22). Then, application of Icp is suspended (S30) and a routine is held on standby until a time of 25 ms elapses (S35). At the point of time when the time of 25 ms has elapsed, the voltage across the electrodes on the opposite sides of the electromotive force cell is detected (S40) and labeled as Vs1 (S45). A resistance value Rs1 is calculated from Vs0, Vs1 and Icp (S50).