Abstract: An exhaust gas analyzing system makes it possible to determine appropriate maintenance timing of sampling pumps in the system, including sampling pumps and provided in a main flow path in order to sample exhaust gas sent from an introduction port, analysis parts provided on the upstream side or downstream side of the sampling pumps and in the main flow path, flow meters provided on the upstream side or downstream side of the analysis parts in the main flow path, and pump abnormality determination parts and for determining abnormality of the sampling pumps by comparing pump flow rates obtained by the flow meters to a predetermined abnormal flow rate.

Abstract: The present invention is one that can, with suppressing moisture from condensing, easily set a dilution ratio to that enabling measurement accuracy to be improved, and provided with a constant volume sampling part that samples mixed gas that is controlled to have a constant flow rate, wherein the constant volume sampling part is provided with: a main flow path that is connected with an exhaust gas flow path and a diluent gas flow path, and intended to flow the mixed gas that is a mixture of exhaust gas and diluent gas; a constant flow rate mechanism that is configured to control a flow rate of the mixed gas to the constant flow rate; and a moisture detecting part that is provided on an upstream side of the constant flow rate mechanism to detect moisture in the mixed gas or the diluent gas.

Abstract: The present invention is one that is, in an exhaust gas analyzing apparatus used together with a CVS mechanism, adapted to be able to make an analysis with high accuracy, and an analyzing mechanism is provided with: a target component concentration meter that measures a moisture-influenced concentration related value that is a value related to concentration of a measuring target component in a state of being influenced by moisture; and a moisture concentration meter that measures a moisture concentration related value that is a value related to concentration of the moisture, and adapted to, on the basis of the moisture concentration related value, eliminate the influence of the moisture from the moisture-influenced concentration related value to calculate each of the first concentration related value and the second concentration related value.

Abstract: An exhaust gas analyzing apparatus provided a first filter flow path with a first filter, a second filter flow path provided with a second filter, an exhaust gas analyzing part for analyzing exhaust gas passing through the first filter or the second filter, a flow path switching mechanism for switching between the first filter flow path and the second filter flow path. A pulse purge mechanism is provided for supplying purge gas to the filters, in the filter flow paths, in a pulsed manner, and in the case where a pressure difference between an upstream side and a downstream side of the filter provided in one filter flow path where the exhaust gas flows becomes equal to or larger than a predetermined value, the one filter flow path is switched to the other one, and purge gas is supplied to the filter provided in the one filter flow path in the pulsed manner.

Abstract: A gas analyzing system that can perform calibration without being influenced by the deterioration of span gas in a span gas supply line. An open-close device control part that receives a calibration start signal issuing an instruction to start zero calibration and span calibration, and controls an open-close device for a span gas flow path. An open-close device for a zero gas flow path, wherein if the open-close device control part receives a new calibration start signal after a predetermined time has passed since previous calibration was performed, before the span calibration is started, for a predetermined time, the open-close device control part controls the open-close device for the span gas flow path so as to open the open-close device for the span gas flow path, and thereby purges span gas that remains in the span gas flow path.

Abstract: The present invention is intended to be able to determine an appropriate purge time in a hydrogen flame ionization type exhaust gas analyzer and a system incorporating the analyzer which includes: a collector electrode for capturing ions generated from exhaust gas by hydrogen flame; an acquisition circuit adapted to acquire ion current caused by the ions captured by the collector electrode; and an abnormality determining part for determining an abnormality in the case where a difference between a first output value of the acquisition circuit in the case where there flows no ion current caused by the exhaust gas to the collector electrode and a second output value of the acquisition circuit in the case where zero gas is introduced into the hydrogen flame is equal to a predetermined value.

Abstract: An analyzer calibrating system intended to reduce calibration time and a consumption amount of calibration gas in the case of concurrently calibrating a plurality of analyzers and includes: a calibration gas line for concurrently supplying the same calibration gas to a plurality of analyzers; and a control unit adapted to determine whether or not an output value of each of the plurality of analyzers supplied with the same calibration gas is stable. The control unit calibrates the analyzer having the output value determined to be stable and stops the supply of the calibration gas to the analyzer having completed with the calibration.

Abstract: The present invention is one that can, with suppressing moisture from condensing, easily set a dilution ratio to that enabling measurement accuracy to be improved, and provided with a constant volume sampling part that samples mixed gas that is controlled to have a constant flow rate, wherein the constant volume sampling part is provided with: a main flow path that is connected with an exhaust gas flow path and a diluent gas flow path, and intended to flow the mixed gas that is a mixture of exhaust gas and diluent gas; a constant flow rate mechanism that is configured to control a flow rate of the mixed gas to the constant flow rate; and a moisture detecting part that is provided on an upstream side of the constant flow rate mechanism to detect moisture in the mixed gas or the diluent gas.

Abstract: The present invention is one that is, in an exhaust gas analyzing apparatus used together with a CVS mechanism, adapted to be able to make an analysis with high accuracy, and an analyzing mechanism is provided with: a target component concentration meter that measures a moisture-influenced concentration related value that is a value related to concentration of a measuring target component in a state of being influenced by moisture; and a moisture concentration meter that measures a moisture concentration related value that is a value related to concentration of the moisture, and adapted to, on the basis of the moisture concentration related value, eliminate the influence of the moisture from the moisture-influenced concentration related value to calculate each of the first concentration related value and the second concentration related value.

Abstract: The present invention is intended to be able to determine an appropriate purge time in a hydrogen flame ionization type exhaust gas analyzer and a system incorporating the analyzer which includes: a collector electrode for capturing ions generated from exhaust gas by hydrogen flame; an acquisition circuit adapted to acquire ion current caused by the ions captured by the collector electrode; and an abnormality determining part for determining an abnormality in the case where a difference between a first output value of the acquisition circuit in the case where there flows no ion current caused by the exhaust gas to the collector electrode and a second output value of the acquisition circuit in the case where zero gas is introduced into the hydrogen flame is equal to a predetermined value.

Abstract: An exhaust gas analyzing apparatus provided a first filter flow path with a first filter, a second filter flow path provided with a second filter, an exhaust gas analyzing part for analyzing exhaust gas passing through the first filter or the second filter, a flow path switching mechanism for switching between the first filter flow path and the second filter flow path. A pulse purge mechanism is provided for supplying purge gas to the filters, in the filter flow paths, in a pulsed manner, and in the case where a pressure difference between an upstream side and a downstream side of the filter provided in one filter flow path where the exhaust gas flows becomes equal to or larger than a predetermined value, the one filter flow path is switched to the other one, and purge gas is supplied to the filter provided in the one filter flow path in the pulsed manner.

Abstract: An analyzer calibrating system intended to reduce calibration time and a consumption amount of calibration gas in the case of concurrently calibrating a plurality of analyzers and includes: a calibration gas line for concurrently supplying the same calibration gas to a plurality of analyzers; and a control unit adapted to determine whether or not an output value of each of the plurality of analyzers supplied with the same calibration gas is stable. The control unit calibrates the analyzer having the output value determined to be stable and stops the supply of the calibration gas to the analyzer having completed with the calibration.

Abstract: An exhaust gas analyzing system makes it possible to determine appropriate maintenance timing of sampling pumps in the system, including sampling pumps and provided in a main flow path in order to sample exhaust gas sent from an introduction port, analysis parts provided on the upstream side or downstream side of the sampling pumps and in the main flow path, flow meters provided on the upstream side or downstream side of the analysis parts in the main flow path, and pump abnormality determination parts and for determining abnormality of the sampling pumps by comparing pump flow rates obtained by the flow meters to a predetermined abnormal flow rate.

Abstract: An EGR ratio measuring device comprises a pair of nondispersive infrared gas analyzers that correct a water influence and measure a concentration of CO2 in a gas containing water, an intake air introduction line that is connected to an intake air pipe of an internal combustion engine and introduces a part of the intake air into one nondispersive infrared gas analyzer without removing the water, an exhaust gas introduction line that is connected to an exhaust gas pipe of the internal combustion engine and introduces a part of the exhaust gas into the other nondispersive infrared gas analyzer without removing the water, and a temperature adjusting mechanism that keeps a temperature of whole of the introduction lines and a temperature of the nondispersive infrared gas analyzers so as not to condense dew.

Abstract: A gas analyzing system that can perform calibration without being influenced by the deterioration of span gas in a span gas supply line. An open-close device control part that receives a calibration start signal issuing an instruction to start zero calibration and span calibration, and controls an open-close device for a span gas flow path. An open-close device for a zero gas flow path, wherein if the open-close device control part receives a new calibration start signal after a predetermined time has passed since previous calibration was performed, before the span calibration is started, for a predetermined time, the open-close device control part controls the open-close device for the span gas flow path so as to open the open-close device for the span gas flow path, and thereby purges span gas that remains in the span gas flow path.

Abstract: In order to improve a measurement accuracy of an EGR ratio and to downsize the device and to save labor, the EGR ratio measuring device comprises a pair of nondispersive infrared gas analyzers (11), (12) that have a function of correcting a water influence and that can measure a concentration of CO2 in a gas containing water, an intake air introduction line (L1) that is connected to an intake air pipe (INT) of an internal combustion engine (EG) and that introduces a part of the intake air into one nondispersive infrared gas analyzer (11) without removing the water, an exhaust gas introduction line (L2) that is connected to an exhaust gas pipe (EXT) of the internal combustion engine (EG) and that introduces a part of the exhaust gas into the other nondispersive infrared gas analyzer (12) without removing the water, and a temperature adjusting mechanism (81a˜81c), (82a˜82c) that keeps a temperature of whole of the introduction lines (L1), (L2) and a temperature of the nondispersive infrared gas analyzers (11),

Abstract: An exhaust gas measuring bag which can smoothly exhaust gas and perform back purge and back dump in a short period of time without leading to an increase in size and costs of the system is provided. The exhaust gas measuring bag includes a gas connection part which is connected to an external passage flowing measurement gas therethrough for analyzing various components included in the exhaust gas. A pipe is connected to an internal passage of the gas connection part and a plurality of gas ejection holes for ejecting the gas are formed on the pipe. A bag body is deformable and has an internal space for storing at least a connection side of the gas connection part to the pipe, and the whole of the pipe therein. The pipe encloses the gas ejected from the gas ejection holes into the internal space therein. A gas exhaust port is provided, at the gas connection part or a member separated from the gas connection part, and exhausts the gas enclosed in the internal space to the external passage.

Abstract: In analyzing the concentration of an objective component contained in a sample gas by a gas analyzer, an output of the gas analyzer is corrected at a fixed point by applying the relationship between the concentration of a coexistent gas and a span sensitivity of the objective component to make it possible to simply correct the effect of the coexistent gas. In addition, by inputting, at the time of the calibration of the gas analyzer, the information on to what extent the base gas composition differs from the average amount of the actual sample along with the concentration amount of the objective component in the calibration gas, the sensitivity adjustment coefficient is determined by taking into account the effect amount which is previously stored in the gas analyzer, by which the effect amount of the span sensitivity by the difference of the base gas compositions in the calibration gas and the sample gas is suppressed, and the effect of the coexistent gas is canceled to the best possible extent.

Abstract: A method and apparatus for detecting NO.sub.x by chemiluminescence. The apparatus includes a sample gas line having an inlet port for receiving a sample gas, a NO.sub.x converter connected to the sample gas line, a N.sub.2 diluting gas line connected to the sample gas line upstream from the NO.sub.x converter, a bypass exhaust lie connected to the sample gas line, and a chemiluminescence analyzer connected to the NO.sub.x converter. The sample gas, which contains a NO.sub.x component, is introduced to the sample gas line through an inlet portion. The sample gas is diluted with nitrogen gas from the nitrogen diluting gas line, and the NO.sub.x component in the sample gas is converted to NO by the NO.sub.x converter. The chemiluminescence analyzer detects the NO.sub.x component.