In order to provide an exhaust gas measurement apparatus having a simpler configuration capable measuring a concentration of a predetermined component contained in exhaust gas under various situations without deteriorating a measurement accuracy, there is provided a sampling mechanism that can select any one of two states, i.e., a first operation mode for outputting the sampled exhaust gas without dilution and a second operation mode for outputting the sampling exhaust gas mixed with dilution gas. In a situation where the sampling mechanism is operating in the first operation mode, in the case where the concentration of the predetermined component measured by a measurement apparatus body exceeds a predetermined first threshold value, the sampling mechanism is controlled such that the first operation mode thereof is changed to the second operation mode.

An exhaust gas analysis apparatus includes an exhaust gas flow channel, a pump, and a heat exchanger. The exhaust gas flow channel is designed to permit passage of exhaust gas of an internal combustion engine, and is provided with an analysis device. The pump is disposed downstream of the analysis device in the exhaust gas flow channel. The heat exchanger is designed to receive at least one of heat of the pump and heat of exhaust gas passing downstream of the pump, and to use the heat to heat exhaust gas passing upstream of the pump in the exhaust gas flow channel.

A device and method for correcting emissions can include a first sensor that measures a sample of air not containing an exhaust gas, and a second sensor, wherein the exhaust gas enters a settling chamber and a relative humidity of the exhaust gas is measured by the second sensor. A microcomputer can calculate a mass of water vapor in the sample of air measured by the first sensor and in the exhaust gas measured by the second sensor and can determine a dilution factor of the measured exhaust gas. The dilution factor can be used for correcting emissions based on the measurements of the exhaust gas made by the first sensor and the second sensor. The first and second sensors can comprise one or more of, for example, a relative humidity sensor, a dew point sensor, a trace water vapor sensor and/or other types of sensors.

An exhaust gas sampling system according to the principles of the present disclosure includes a dilution air source that provides dilution air to a first flow path and a first flow meter that measures a first mass flow rate in the first flow path. The system further includes a sampling probe, a second flow meter, a first valve, and a leak detection module. The sampling probe provides exhaust gas to the first flow path at a location downstream from the first flow meter. The second flow meter measures a second mass flow rate in the first flow path at a location downstream from the sampling probe. The first valve regulates exhaust gas flow from the sampling probe to the second flow meter. The leak detection module detects a leak in the system based on measurements of the first and second mass flow rates taken when the first valve is closed.

The present invention includes an exhaust gas flow channel that permits passage of an exhaust gas, a diluent gas flow channel that permits passage of a diluent gas, a main flow channel that permits passage of a diluted exhaust gas, a diluted exhaust gas flow rate measurement mechanism disposed on the main flow channel, and a diluent gas flow rate measurement mechanism disposed on the diluent gas flow channel. The diluted exhaust gas flow rate measurement mechanism and the diluent gas flow rate measurement mechanism each have a pressure sensor section. Furthermore, a pressure sensitive element of the pressure sensor section in the diluted exhaust gas flow rate measurement mechanism, and a pressure sensitive element of the pressure sensor section in the diluent gas flow rate measurement mechanism, are oriented in an identical direction in order to reduce an influence of acceleration in association with movement of a mobile object.

An exhaust emission measurement method comprises the steps: testing a Plug-In Hybrid Vehicle having a combustion engine and an electric motor during a test phase of a predetermined time length; sampling of exhaust into dilution air; collecting the diluted exhaust in a diluted exhaust bag, when the combustion engine is operating; intermittently filling of the bag when a combustion engine of the Plug-In Hybrid Vehicle is operating; at a certain time before the end of the test phase, changing sampling from intermittent filling to continuous filling of the bag in order to get enough bag volume for an accurate analyzer reading.

A system for taking exhaust gas samples from internal combustion engines includes an exhaust gas duct comprising an outflow cross section and an exhaust gas inlet. The exhaust gas duct communicates with an exhaust gas source via the exhaust gas inlet. An air duct takes in ambient air via a filter. The outflow cross section is concentric in the air duct. A mixing zone is arranged downstream of the outflow cross section. A dilution tunnel has an exhaust gas/air mixture flow therethrough. An annular orifice is arranged downstream of the outflow cross section in the dilution tunnel. A flow deflection device is arranged upstream of the annular orifice and downstream of the outflow cross section. The flow deflection device deflects the exhaust gas/air mixture so that it departs from a center axis of the dilution tunnel immediately downstream of the flow deflection device in an axially symmetrical manner.

An apparatus for measuring aerosol particles includes a charging unit to form charged particles by charging particles of an aerosol sample flow by diffusion charging, and a collecting unit to provide an electric current by collecting charges from the charged particles by diffusion of the charged particles, the electric current being indicative of number density of aerosol particles of the aerosol sample flow. The internal pressure of the collecting unit is maintained at a reduced value in order to provide a flat response of the electric current for detecting nanoparticles of different sizes.

A device and method for correcting emissions can include a first sensor that measures a sample of air not containing an exhaust gas, and a second sensor, wherein the exhaust gas enters a settling chamber and a relative humidity of the exhaust gas is measured by the second sensor. A microcomputer can calculate a mass of water vapor in the sample of air measured by the first sensor and in the exhaust gas measured by the second sensor and can determine a dilution factor of the measured exhaust gas. The dilution factor can be used for correcting emissions based on the measurements of the exhaust gas made by the first sensor and the second sensor. The first and second sensors can comprise one or more of, for example, a relative humidity sensor, a dew point sensor, a trace water vapor sensor and/or other types of sensors.

A particle measuring apparatus according to an embodiment includes a first supply part that introduces first gas. A second supply part introduces second gas having been filtered. A light source irradiates mixture gas including the first gas and the second gas with light. A light detector detects reflected light from the mixture gas and measures number of particles contained in the mixture gas. A pump sucks the mixture gas.