Abstract: A method for detecting the concentration of a specific component in gas discharged from an internal combustion engine, which includes detecting the concentration of the specific component under certain driving conditions to determine a zero point, which indicates a zero concentration of the specific component, of the detection output; calibrating the detection output of the gas sensor based on the determined zero point; and detecting the concentration of the specific component in exhaust gas based on the calibrated detection output.

Abstract: An ballpoint pen has: a tip body made of metal having an front edge part and a plurality of inward protrusions; a ball rotatably embraced between the front edge part and the inward protrusions; and a rod part urging the ball forwardly and bringing the ball into close contact with the inner surface of the front edge part, wherein ink outflow gaps are formed each between the adjacent inward protrusions, the rod part is inserted into the central part of the ink outflow gaps, the diameter of a virtual inscribed circle of the central part of the ink outflow gaps is larger than the outside diameter of the rod part, and a minimum dimension of each the ink outflow gap is smaller than the outside diameter of the rod part.

Abstract: Ink and an ink follower are reserved in an ink tube. An elastic member urges a ball forward. When an outflow of ink is measured at intervals of a writing distance of 100 m, the value of outflow of ink per writing distance of 100 m until a measurement time just before outflow of 80% of the amount of charged ink from the start of writing is selected to be in a range between a value smaller by 20 mg than the outflow of ink in the writing distance range of from 0 m to 100 m and a value larger by 20 mg than the outflow of ink in the writing distance range of from 0 m to 100 m.

Abstract: Ink and an ink follower are reserved in an ink tube. An elastic member urges a ball forward. When an outflow of ink is measured at intervals of a writing distance of 100 m, the value of outflow of ink per writing distance of 100 m until a measurement time just before outflow of 80% of the amount of charged ink from the start of writing is selected to be in a range between a value smaller by 20 mg than the outflow of ink in the writing distance range of from 0 m to 100 m and a value larger by 20 mg than the outflow of ink in the writing distance range of from 0 m to 100 m.

Abstract: A method for detecting the concentration of a specific gas (NOx) in an engine exhaust gas using a gas sensor and a process of correcting the gas sensor. According to the correcting process, the amount of moisture in the exhaust gas is estimated, then a a gas concentration detection signal output by the gas sensor on the basis of an estimated amount of moisture is corrected. Finally, the effect of the amount of moisture in the exhaust gas is removed or reduced from the detected value of gas concentration.

Abstract: A gas sensor (1a) having a laminate including an alumina substrate (11) having a heating resister (115) embedded in the alumina substrate (11); a first oxygen-ion conductive solid electrolyte layer (131) containing zirconia and alumina and partly constituting an oxygen-detecting cell (13) and the first solid electrolyte layer (131) being laminated with said alumina substrate (11); a second oxygen-ion conductive solid electrolyte layer (121) containing zirconia and alumina and partly constituting an oxygen-pumping cell (12); an ion-leakage preventing ceramic spacer (143) for preventing oxygen-ions from leaking from the second oxygen-ion conductive solid electrolyte layer (121) to the first oxygen-ion conductive solid electrolyte layer (131), the spacer (143) being laminated between the first and second oxygen-ion conductive solid electrolyte layers (131, 121); and a gas-diffusion space (141) formed between an electrode (133) of the oxygen-detecting cell (13) and an electrodes (126) of the oxygen-pumping cell (

Abstract: Method and sensor for measuring accurate measurement of NOx concentration in an exhaust gas containing O2,H2O, CO2 and NOx and a NOx gas concentration sensor. A first oxygen pump cell sufficiently pumps out oxygen in a measurement gas such as not to decompose NOx. A pair of electrodes is provided on an inner side and an outer side of a second measurement chamber into which the gas is introduced from a first measurement chamber via a diffusion resistance. A voltage is impressed across the paired electrodes for decomposing NOx in the second measurement chamber to dissociate oxygen which causes the current to flow in a second oxygen ion pump cell. The NOx gas concentration is measured for this current. The voltage impressed across the paired electrodes of the second oxygen ion pump cell is set so as not to dissociate H2O and CO2 present in the second measurement chamber.

Abstract: A method and apparatus which enable accurate measurement of the concentration of NOx in a gas under measurement, even when the NOx concentration is low. A gas under measurement is introduced into a first chamber 3 through a first diffusion passage 2. A pump voltage V1 is applied from a direct-current power source E1 to a first oxygen ion pump cell 6 such that the electric potential of an oxygen-concentration-measuring cell 7 is held constant. As a result, oxygen is pumped out from the first chamber 3 such that the oxygen concentration measured at an inlet to a second chamber 5 becomes constant. A first pump current Ip1 flowing to the first oxygen ion pump cell 6 is measured. Next, the gas under measurement contained in the first chamber 3 is introduced into the second chamber 5 through a second diffusion passage 4.

Abstract: A method for detecting the concentration of a specific gas (NOx) in an engine exhaust gas using a gas sensor and a process of correcting the gas sensor. According to the correcting process, the amount of moisture in the exhaust gas is estimated, then a gas concentration detection signal output by the gas sensor on the basis of an estimated amount of moisture is corrected.

Abstract: A method and apparatus which enable accurate measurement of the concentration of NOx in a gas under measurement, even when the NOx concentration is low. A gas under measurement is introduced into a first chamber 3 through a first diffusion passage 2. A pump voltage V1 is applied from a direct-current power source E1 to a first oxygen ion pump cell 6 such that the electric potential of an oxygen-concentration-measuring cell 7 is held constant. As a result, oxygen is pumped out from the first chamber 3 such that the oxygen concentration measured at an inlet to a second chamber 5 becomes constant. A first pump current Ip1 flowing to the first oxygen ion pump cell 6 is measured. Next, the gas under measurement contained in the first chamber 3 is introduced into the second chamber 5 through a second diffusion passage 4.

Abstract: A method for detecting the concentration of a specific gas (NOx) in an engine exhaust gas using a gas sensor and a process of correcting the gas sensor. According to the correcting process, the amount of moisture in the exhaust gas is estimated, then a a gas concentration detection signal output by the gas sensor on the basis of an estimated amount of moisture is corrected.

Abstract: A nitrogen oxide concentration detector has a first measurement chamber 2 into which is introduced a measurement gas via a first diffusion resistance 1; an oxygen concentration detection electrode 7a for measuring the oxygen concentration in the measurement gas in said first measurement chamber 1; a first oxygen ion pump cell 6 for pumping out oxygen in the measurement gas from said first measurement chamber 2 based on the potential of said oxygen concentration detection electrode 7a; a second measurement chamber 8 into which the gas is introduced from said first measurement chamber 2 via a second diffusion resistance 3; and a second oxygen ion pump cell 8 having a pair of electrodes 8a,8b across which a voltage is applied to decompose NOx in the second measurement chamber 4 to pump out dissociated oxygen to cause a circuit Ip2 corresponding to the NOx concentration to flow in the second oxygen ion pump cell 8. Variation of NOx concentration is a function of variation of Ip2.

Abstract: A nitrogen oxide concentration detector has a first measurement chamber 2 into which is introduced a measurement gas via a first diffusion resistance 1; an oxygen concentration detection electrode 7a for measuring the oxygen concentration in the measurement gas in said first measurement chamber 1; a first oxygen ion pump cell 6 for pumping out oxygen in the measurement gas from said first measurement chamber 2 based on the potential of said oxygen concentration detection electrode 7a; a second measurement chamber 8 into which the gas is introduced from said first measurement chamber 2 via a second diffusion resistance 3; and a second oxygen ion pump cell 8 having a pair of electrodes 8a,8b across which a voltage is applied to decompose NOx in the second measurement chamber 4 to pump out dissociated oxygen to cause a current Ip2 corresponding to the NOx concentration to flow in the second oxygen ion pump cell 8. Variation of NOx concentration is a function of variation of Ip2.

Abstract: An apparatus and method using a two-serial space sensor (having first and second internal spaces 2,3) for accurately measuring NOx concentration in gas, e.g., exhausted from an internal combustion engine. Both NOx (nitrogen oxide) and oxygen are forced to be partially dissociated in the first space 2 to an oxygen concentration level of 2×10−7 to 2×10−10 atm by pumping out oxygen from the first space 2. The NOx concentration is determined based on the second current measured in the second space 4 and based on the NO dissociation percentage in the first chamber which is 0.5-50%, or preferably 2-20%. The NOx measurement accuracy is further improved when the above oxygen concentration level is maintained from 2×10−8 to 2×10−9 and the temperature drift of the sensor is maintained within ±5° C. under a sensor temperature range of 700-900° C.

Abstract: An NOx sensor capable of accurately determining the concentration of NOx contained in a gas to be analyzed (measurement gas) using a simple circuit. The NOx sensor includes a first measurement space and a second measurement space. The first measurement space communicates with the measurement gas via a first diffusion controlling layer, and the second measurement space communicates with the first measurement space via a second diffusion controlling layer. A first pumping current IP1 is controlled such that an output from a Vs cell is used as a reference voltage VC0 to control the amount of oxygen flowing into the second measurement space at a constant level. A constant voltage is applied to the second pumping cell so as to decompose the NOx component of the measurement gas contained in the second measurement space, and to pump out the resulting oxygen from the second measurement space. Accordingly, the concentration of NOx contained in the measurement gas can be obtained from second pumping current IP2.

Abstract: This is a method and apparatus for accurately determining a NOx concentration of a measurement gas that contains H2O and/or CO2, without being affected by a dissociation of H2O and/or CO2.

Abstract: A small-sized inexpensive nitrogen oxide concentration sensor capable of measuring the concentration of the nitrogen oxide in a measuring gas to a high accuracy. A first oxygen pumping cell, an oxygen concentration measuring cell and a second oxygen pumping cell are formed in different solid electrolyte layers of zirconia and electrodes of oxygen concentration measuring cell are isolated from electrodes of the oxygen pumping cells by insulating film.

Abstract: A ballpoint pen tip including a metallic pipe having a plurality of inwardly projecting portions at a neighborhood of a front end portion of the pipe at regular intervals, and a front end edge portion at a front end of the pipe, and a ball rotatably held between the front end edge portion and the plurality of inwardly projecting portions, wherein the pipe satisfies a relation of A/T.ltoreq.5.8 where A is an outer diameter of the ball and T is a thickness 10 of the pipe, and also the relation of B/T.ltoreq.2.3 where B is a diameter of a virtual inscribing circle contacting a top of the plurality of inwardly projecting portions and T is the same as above.