KR20230014367A - Automobile exhust gas measurement device and method of automobile exhust gas measurement using the same - Google Patents

Abstract

According to one aspect of the present invention, provided is a device for measuring vehicle exhaust gas. In the device for measuring vehicle exhaust gas, a gas inlet through which vehicle exhaust gas flows, an electronic gas valve connected to the gas inlet, a pump assisting inflow of the vehicle exhaust gas, a first measurement cell including a non-dispersive infrared gas sensor, a second measurement cell including a zirconia sensor, and a gas outlet through which the vehicle exhaust gas is discharged are connected in sequence, wherein an atmospheric inlet through which atmospheric air is introduced is further connected to the electronic gas valve, and the electronic gas valve can selectively allow or block connection to an exhaust gas inlet and the atmospheric inlet. Thus, the device for measuring vehicle exhaust gas has a long life and high accuracy without being affected by moisture.

Description

Automobile exhaust gas measurement device and method of automobile exhaust gas measurement using the same}

The present invention relates to a vehicle exhaust gas measuring device and a method for measuring vehicle exhaust gas using the same.

Vehicles in operation are obliged by law to undergo vehicle inspections every year for business use and every two years for private vehicles. Among the vehicle inspection items, in the case of a gasoline vehicle, the components of the exhaust gas were measured, so that the components that affect the environment must be discharged below the legal limit for operation. Emission gas inspection items include carbon monoxide (CO), hydrocarbons (HC), carbon dioxide (CO ₂ ), oxygen (O ₂ ), which affects the proper fuel efficiency of automobiles, and nitrogen oxide (NO _X ), which has recently become a problem. there is. In the regular inspection, only carbon monoxide (CO), hydrocarbons (HC), and oxygen (O ₂ ) are measured, and in the detailed inspection, carbon dioxide (CO ₂ ) and nitrogen oxides (NO _X ) are also measured.

In most exhaust gas measurement devices currently in use, CO/HC/CO ₂ is measured by non-dispersive infrared (NDIR) method, O ₂ is measured by electrochemical method, and NOx is measured by electrochemical method using liquid electrolyte or non-dispersive infrared (NDIR) method. It is measured by the dispersive infrared method. In the case of measuring exhaust gas by an electrochemical method using a liquid electrolyte, a gas permeable membrane is used around the sensor. However, if the gas permeable membrane is covered with moisture, the exhaust gas cannot reach the inside of the sensor, resulting in measurement errors. In addition, in the case of an electrochemical sensor, the life of the sensor is generally 1 or 2 years even in a good environment, and the life of the sensor is significantly reduced when the use environment is not good. Therefore, there is a problem that the measured value of the exhaust gas is reduced or measured as 0 due to moisture in the exhaust gas of the vehicle, and the concentration of the corresponding gas is measured as 0 using a sensor whose life is over, so that accurate measurement cannot be made.

One aspect of the present invention is to provide a vehicle exhaust gas measuring device having a long life and high accuracy without being affected by moisture.

Another aspect of the present invention is to provide a method for measuring vehicle exhaust gas with high accuracy without being affected by moisture.

According to one aspect of the present invention

a gas inlet through which vehicle exhaust gas flows;

an electronic gas valve connected to the gas inlet;

a pump assisting inflow of the vehicle exhaust gas;

A first measurement cell including a non-dispersive infrared gas sensor;

a second measuring cell including a zirconia sensor; and

a gas outlet through which the vehicle exhaust gas is discharged; are connected in sequence,

An atmospheric inlet through which atmospheric air is introduced is further connected to the electronic gas valve,

The electronic gas valve provides a vehicle exhaust gas measuring device capable of selectively allowing or blocking connections to the exhaust gas inlet and the air inlet.

The first measurement cell may measure the concentrations of carbon monoxide, hydrocarbons and carbon dioxide.

The second measurement cell may measure the concentrations of nitrogen oxide and oxygen.

The second measuring cell is

the zirconia sensor;

a cell housing made of a heat-resistant material surrounding the zirconia sensor;

cell inlets and cell outlets located in opposite directions within the cell housing, through which the vehicle exhaust gas enters and exits; and

and a cell space between the zirconia sensor and the cell housing, in which the vehicle exhaust gas is filled.

The cell space may be 10 cm ³ or less.

A distance between the zirconia sensor and the cell housing may be 1 cm or less.

The cell housing may be made of Teflon (PTFE) or PEEK (polyether ether ketone).

The apparatus may further include a main filter disposed between the gas inlet and the pump, and the main filter may include a water removal filter for removing water and a dust removal filter for removing dust.

A zero filter may be further included between the atmospheric inlet and the pump.

A pressure sensor between the main filter and the electromagnetic valve may be further included.

A span calibration gas inlet may be further included between the pump and the first measurement cell, and span calibration gas may be introduced from the span calibration gas inlet.

The temperature in the second measurement cell may be in the range of 0 °C to 100 °C.

The pressure in the second measurement cell may be in the range of 0.5 atm to 2 atm.

According to another aspect of the present invention

Providing the above-mentioned automobile emission measuring device;

introducing vehicle exhaust gas into the vehicle exhaust gas measuring device through the gas inlet;

Measuring the concentrations of carbon monoxide, hydrocarbons and carbon dioxide in the introduced vehicle exhaust gas; and

It provides a method for measuring vehicle exhaust gas including; measuring the concentration of nitrogen oxides in the vehicle exhaust gas in which the concentrations of hydrocarbons and carbon dioxide are measured.

Performing zero point calibration of the non-dispersive infrared type gas sensor for hydrocarbons and carbon dioxide or zero point calibration of the zirconia sensor for nitrogen oxide using the air introduced from the air inlet before the vehicle exhaust gas is introduced. can include more.

Span calibration of the non-dispersive infrared type gas sensor for hydrocarbon and carbon dioxide or span calibration of the zirconia sensor for nitrogen oxide using the span calibration gas introduced from the span calibration gas inlet before the vehicle exhaust gas is introduced. It may further include steps to perform.

The vehicle exhaust gas measuring device of the present invention is not affected by moisture by using a zirconia sensor, and can economically maintain measurement accuracy without periodic replacement of an expensive sensor. In addition, the vehicle exhaust gas measuring method of the present invention can accurately measure vehicle exhaust gas without being affected by moisture by using the vehicle exhaust gas measuring device and performing zero point calibration and span calibration.

1 is a schematic diagram of a nitrogen oxide measuring cell for measuring nitrogen oxide in vehicle exhaust gas according to an embodiment.
2 is a block diagram of a vehicle exhaust gas measuring device according to an embodiment.
3 is a flowchart sequentially illustrating a method for measuring nitrogen oxides in vehicle exhaust gas according to the present embodiment.
4 is a flowchart sequentially illustrating a method for measuring vehicle exhaust gas according to an embodiment.

Terms used in this specification are only used to describe specific test examples and are not intended to limit the creative spirit of the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. Hereinafter, the term "comprises" or "has" is intended to indicate that features, numbers, steps, operations, components, parts, components, materials, or combinations thereof described in the specification exist, and one or more It should be understood that it does not preclude the possibility of addition or existence of other features, numbers, steps, operations, components, parts, components, materials or combinations thereof.

In this specification, “CO/HC/CO ₂ ” means carbon monoxide (CO), hydrocarbon (HC), and/or carbon dioxide (CO ₂ ).

As used herein, "hydrocarbon" refers to various incompletely combusted compounds composed of carbon and hydrogen.

The compounds of carbon and hydrogen generated at this time are made into very diverse substances depending on the state of combustion, and they are collectively treated as hydrocarbon compounds.

In this specification, "NO _X " means nitrogen oxides.

In this specification, “nitrogen oxide” includes NO, NO ₂ or N ₂ O.

In this specification, combustion gas refers to gas that comes out while fuel is burned in an engine of a vehicle.

Hereinafter, a cell for measuring nitrogen oxides in vehicle exhaust gas according to embodiments of the present invention, a device for measuring vehicle exhaust gas using the same, and a method for measuring vehicle exhaust gas will be described in detail.

(Nitrogen oxide measuring cell)

1 is a schematic diagram of a nitrogen oxide measuring cell 50 for measuring nitrogen oxide in vehicle exhaust gas according to an embodiment. Referring to FIG. 1, the nitrogen oxide measuring cell 50 includes a zirconia sensor 51, a cell housing 52, and a cell space filled with a measuring gas (exhaust gas) between the zirconia sensor 51 and the cell housing 52. (53). The cell housing 52 includes a cell inlet 54 through which measurement gas enters and a cell outlet 55 out of which the cell inlet 54 and the cell outlet 55 may be located diagonally from each other. The cell space 53 has a minimum volume for the measurement gas. The cell space 53 may vary depending on the size of the zirconia sensor 51, and may be, for example, 10 cm ³ or less. The distance d between the zirconia sensor 51 and the cell housing 52 may be, for example, 1 cm or less, for example, 0.7 cm or less. The spacing d may be, for example, 0.1 cm or more, for example 0.3 cm or more. The measurement gas does not remain in the cell space 53 by arranging the inlet 54 and the outlet 55 of the measurement cell 50 at diagonal positions while minimizing the distance between the zirconia sensor 51 and the cell housing 52. . That is, the measuring cell 50 according to the present embodiment does not have a dead volume inside the cell, and thus the exhaust gas can flow smoothly into and out of the measuring cell 50, and thus the exhaust gas can be well transmitted into the zirconia sensor 51.

The zirconia sensor 51 may be a known zirconia sensor capable of measuring nitrogen oxide. A zirconia sensor is a gas sensor including two electrodes and a solid electrolyte between them, in which the solid electrolyte contains zirconia. The zirconia sensor 51 can comprehensively measure the concentration of nitrogen oxides such as NO, NO ₂ , and N ₂ O. In addition, the zirconia sensor 51 may simultaneously measure the concentration of nitrogen oxide and oxygen (O ₂ ). The zirconia sensor 51 may have a dual structure including, for example, a zirconia sensor for measuring the concentration of oxygen (O ₂ ) and a zirconia sensor for measuring the concentration of nitrogen oxide (NO _X ). A zirconia sensor for measuring the concentration of nitrogen oxides can, for example, decompose nitrogen oxides into nitrogen (N ₂ ) and oxygen (O ₂ ) by an internal catalyst and measure the concentration of oxygen (O ₂ ), from which nitrogen The concentration of oxides can be calculated.

The cell housing 52 is made of a heat-resistant material that is not destroyed or deformed by the high-temperature operation of the zirconia sensor 51 . The operating temperature of the zirconia sensor 51 may range from about 700°C to about 800°C. The cell housing 52 may be made of, for example, Teflon (PTFE) or polyether ether ketone (PEEK). Meanwhile, the zirconia sensor 51 operates at a high temperature, but the temperature inside the nitrogen oxide measuring cell 50 may be in the range of 0 °C to 100 °C. The pressure within the nitrogen oxide measuring cell 50 may range from about 0.5 to about 1.5 atmospheres.

The nitrogen oxide measuring cell 50 according to the present invention uses the zirconia sensor 51, so that nitrogen oxide can be measured at low cost and with high accuracy without degradation of the sensor's measurement sensitivity and lifespan according to temperature. In addition, the nitrogen oxide measuring cell 50 according to the present invention does not have a dead volume inside the cell, and low-pressure exhaust gas is quickly transferred to the inside of the zirconia sensor 51, so that the measurement speed and accuracy of the measurement value can be increased. there is.

A conventional device for measuring nitrogen oxides in vehicle exhaust gas uses an electrochemical gas sensor using a liquid electrolyte. An electrochemical gas sensor using a liquid electrolyte includes a gas permeable membrane. If the gas permeable membrane is covered with moisture, vehicle exhaust gas cannot approach the inside of the sensor, resulting in inaccurate measurement values. In particular, in winter when the temperature is low, condensation of moisture on the gas permeable membrane frequently occurs, and the reaction rate may be slowed down due to the freezing of the liquid electrolyte, so that the sensor may not function. If heated to prevent condensation of moisture, the life of the sensor may be shortened. In addition, the liquid electrolyte type gas sensor has a short lifespan of generally one or two years even when the use environment is good.

On the other hand, since the zirconia sensor operates at a high temperature of about 70°C or higher, there is no gas measurement error due to moisture, and the lifespan is more than 10 years, which is much longer than the electrochemical gas sensor using liquid electrolyte. In addition, the reaction speed of the zirconia sensor, that is, the measurement speed, is also shorter than that of an electrochemical gas sensor using a liquid electrolyte.

However, the zirconia sensor is usually used for combustion gas inside the vehicle, and the measurement environment for vehicle exhaust gas outside the vehicle is very different from the measurement environment for combustion gas inside the vehicle. The zirconia sensor inside the vehicle is installed before and after the environmental pollutant removal device in the flow path through which the combustion gas of the vehicle engine flows, and is used to check the removal state of the environmental pollutant or the operating state of the environmental pollutant removal device. Therefore, zirconia sensors used inside vehicles are attached close to the engine of the vehicle and come into direct contact with the combustion gases from the engine. Since the capacity of an automobile engine is usually several thousand cc and operates at more than several hundred rpm, tens of thousands of cc of combustion gas per minute passes through the zirconia sensor, and the pressure of the combustion gas is also quite high due to fuel explosion in the engine. . In addition, since the zirconia sensor inside the vehicle measures continuously while driving, the measurement value is stable.

On the other hand, in an exhaust gas measuring device outside a vehicle, exhaust gas of about thousands of cc per minute usually passes through a zirconia sensor at atmospheric pressure level for a short time. Therefore, it is difficult to accurately measure the concentration of nitrogen oxides in a short period of time from exhaust gas having a significantly lower pressure and flow rate (volume per minute) than combustion gas using a zirconia sensor suitable for measuring combustion gas inside a vehicle. In order to solve this problem, it is necessary to effectively introduce the exhaust gas into the zirconia sensor. To this end, the nitrogen oxide measuring cell 50 according to one embodiment is designed so that there is no dead volume in the cell space 53 inside the measuring cell 50 as described above. As a result, the zirconia sensor responds with a fast response speed even to low-pressure exhaust gas, and the accuracy of the measured value can be increased.

(vehicle emission measuring device)

2 is a block diagram of a vehicle exhaust gas measuring device according to an embodiment. Referring to FIG. 2 , an automobile exhaust gas measuring device 100 according to an embodiment includes a gas inlet 10, an electronic gas valve 20, a pump 30, a first measuring cell 40, and a second measuring cell. 50 and gas outlet 60 are connected in sequence. The electronic gas valve 20 is further connected to an atmospheric inlet 70 through which atmospheric air flows.

The gas inlet 10 may be introduced in the form of a probe into the exhaust port of the vehicle so that the exhaust gas from the exhaust port of the vehicle can be introduced into the vehicle exhaust gas measuring device 100 .

The electronic gas valve 20 can selectively allow or block connections to the gas inlet 10 and the atmospheric inlet 70 . The electronic gas valve 20 may be, for example, a solenoid valve.

A main filter 12 may be positioned between the gas inlet 10 and the electronic valve 20 . The main filter 12 may include a water removal filter (not shown) and/or a dust removal filter (not shown). The water removal filter is connected to the pump 30 to discharge water in vehicle exhaust gas out of the vehicle exhaust gas measuring device 100 through a water inlet (not shown) and a water outlet (not shown). Exhaust gas from which water has been removed can remove dust and the like included in the exhaust gas through a dust removal filter.

A pressure sensor (not shown) may be further included between the main filter 12 and the electromagnetic valve 20 . A pressure sensor (not shown) may play a role in determining whether vehicle exhaust gas is normally inhaled.

The pump 30 lowers the pressure inside the vehicle exhaust gas measuring device 100 to help the vehicle exhaust gas to be sucked in from the gas inlet 10 . As the pump 30, for example, a diaphragm pump or a peristaltic tube pump can be used. On the other hand, the pump 30 is a double pump and can help to discharge water in the exhaust gas as described above.

The first measurement cell 40 measures the concentration of carbon monoxide (CO), hydrocarbon (HC), and/or carbon dioxide (CO ₂ ) in vehicle exhaust gas. To this end, the first measurement cell 40 may include, for example, a non-dispersive infrared gas sensor.

The second measuring cell 50 measures the concentrations of nitrogen oxides (NO _X ) and oxygen (O ₂ ) in vehicle exhaust gas. To this end, the second measurement cell 50 includes a zirconia gas sensor. The second measuring cell 50 is the same as the nitrogen oxide measuring cell 50 according to the previous embodiment. The content of the second measuring cell 50 refers to the content of the nitrogen oxide measuring cell 50 described above.

Vehicle exhaust gas passing through the second measurement cell 50 is discharged through the gas outlet 60 .

The air inlet 70 is a place where air used for zero point control of the zirconia sensor 51 is introduced. The vehicle exhaust gas measuring device 100 performs zero-point calibration of gas sensors in the first measuring cell 40 and the second measuring cell 50 for components to be measured using air introduced from the air inlet 70. can do. When performing zero calibration, the electronic gas valve 20 blocks the connection to the gas inlet 10 and allows connection to the atmospheric inlet 70. When measuring the concentration of vehicle exhaust gas, the electronic gas valve 20 blocks connection to the atmospheric inlet 70 and allows connection to the gas inlet 10 . The zero point calibration may be performed every time the concentration of vehicle exhaust gas is measured, performed at a certain number of times the concentration of vehicle exhaust gas is measured, or may be performed at regular time intervals.

The gas sensor used inside the vehicle is located before and after the environmental pollutant removal device and is used to check the difference in concentration of the gas component measured at the two locations, so it does not require the measurement of the absolute value of the concentration. However, since the vehicle exhaust gas measuring device 100 needs to accurately measure the concentration of a gas component at one location, zero point calibration and span calibration of the gas sensor are required. Air from the air inlet 70 may be used as a gas for zero point calibration of the non-dispersive infrared gas sensor in the first measurement cell 40 and the zirconia sensor in the second measurement cell 50 . The atmosphere can be used as a gas for zero calibration because it does not contain nitrogen oxides (NO _X ), carbon monoxide (CO), hydrocarbons (HC), and carbon dioxide (CO ₂ ).

A zero filter 22 may be further included between the atmospheric inlet 70 and the electromagnetic valve 20 . The zero-point filter 22 is a filter for removing fine dust or highly active gas in the air since they may affect the measurement. As the zero-point filter 22, activated carbon or the like can be used.

Meanwhile, the vehicle exhaust gas measuring device 100 may further include a span calibration gas inlet 80 for span calibration of the gas sensor between the pump 30 and the first measurement cell 40 . The span calibration gas may be a gas for span calibration of the zirconia sensor 51 or a gas for span calibration of a non-dispersive infrared type gas sensor (not shown). N ₂ standard gas can be used as a span calibration gas for nitrogen oxide measurements. Since the non-dispersive infrared gas sensor (not shown) measures concentrations of CO, HC, and CO ₂ , these gases may be used as span calibration gases. Since CO, HC and CO ₂ do not react with each other, they can be mixed in one vessel and used as span calibration gases.

Span calibration can be performed at an appropriate number of times, for example, about once a month or once a week. In order to prevent the exhaust gas from flowing out through the span calibration gas inlet 80 when measuring the exhaust gas, the span calibration gas inlet 80 has a check valve 81 that prevents gas from flowing in one direction and in the opposite direction. It may include, and optionally may further include an orifice (not shown).

The vehicle exhaust gas measuring device 100 according to the present embodiment includes the above-described nitrogen oxide measuring cell 50 for measuring nitrogen oxide, and further includes a unit for zero point calibration and span calibration to measure moisture, temperature, etc. It is possible to accurately measure vehicle exhaust gas without being affected by the measurement environment.

(Method for Measuring Nitrogen Oxide in Vehicle Exhaust Gas)

A method for measuring nitrogen oxides in vehicle exhaust gas according to another embodiment will be described in detail.

3 is a flowchart sequentially illustrating a method for measuring nitrogen oxides in vehicle exhaust gas according to the present embodiment.

Referring to FIG. 3, a nitrogen oxide measuring cell is prepared (S110). As the nitrogen oxide measuring cell, the nitrogen oxide measuring cell 50 as described in FIG. 1 may be used.

The zirconia sensor 51 in the measuring cell 50 is zero-calibrated (S120). The zero point calibration of the zirconia sensor 51 may be performed using a gas that does not contain nitrogen oxide. As a gas that does not contain nitrogen oxides, air can be used, for example.

The zirconia sensor 51 in the measuring cell 50 is span-calibrated (S130). In the step of span calibrating the zirconia sensor 51 , at least one nitrogen oxide standard gas having a constant concentration may be used as a span calibration gas. For example, a span calibration can be performed using either 800 ppm or 1600 ppm of nitrogen oxide gas, or both concentrations.

The concentration of nitrogen oxides in vehicle exhaust gas is measured using the zirconia sensor 51 with the zero point and span calibration (S140).

Zero calibration can be performed at every measurement of the nitrogen oxide concentration, or at regular intervals of the number of measurements or at regular time intervals. Span calibrations can be performed at longer intervals than zero point calibrations. Span calibration can be performed at intervals of one month or one week, for example. Accuracy of the nitrogen oxide concentration measurement value may be improved through zero point calibration and span calibration of the zirconia sensor.

In addition, as described above, in the nitrogen oxide measuring cell 50, the space 53 except for the zirconia sensor 51 is minimized so that nitrogen oxide introduced into the measuring cell 50 can be quickly transferred into the zirconia sensor 51. In addition, since it can escape without remaining in the measurement cell 50, the accuracy of the measurement value can be increased.

(Method of measuring vehicle exhaust gas)

A method for measuring vehicle exhaust gas according to another embodiment will be described in detail.

4 is a flowchart sequentially illustrating a method for measuring vehicle exhaust gas according to an embodiment.

Referring to FIG. 4, an automobile exhaust gas measuring device is prepared (S210). As a vehicle exhaust gas measuring device, the vehicle exhaust gas measuring device 100 as described in FIG. 2 may be used.

The vehicle exhaust gas is introduced into the vehicle exhaust gas measuring device (S220). By inserting the gas inlet 10 into the vehicle exhaust port, vehicle exhaust gas may flow into the vehicle exhaust gas measuring device 100 . The gas inlet 10 may be in the form of a probe. A pump 30 may be used to introduce vehicle exhaust gas into the measuring device 100 .

Water and dust are removed from the introduced vehicle exhaust gas (S230). At this time, a main filter 12 including a water removal filter and a dust removal filter may be used. A pump may be connected to the water removal filter to help remove water contained in the exhaust gas out of the unit. By removing foreign substances such as water and dust from vehicle exhaust gas, the concentration of substances in the exhaust gas can be accurately measured.

The concentration of CO/HC/CO ₂ in the vehicle exhaust gas from which water and foreign substances are removed is measured (S240). For example, the concentration of CO/HC/CO ₂ may be measured by a non-dispersive infrared sensor. Three non-dispersive infrared sensors for each of CO/HC/CO ₂ may be located in the first measurement cell 40 . Concentrations of CO/HC/CO ₂ may be simultaneously measured while the exhaust gas from which water and foreign substances are removed passes through the first measurement cell 40 .

Subsequently, the concentration of nitrogen oxides in vehicle exhaust gas is measured (S250). The concentration of nitrogen oxides may be measured while the vehicle exhaust gas passing through the first measuring cell 40 passes through the second measuring cell 50 including the zirconia sensor. At this time, the concentration of oxygen can be measured simultaneously.

The vehicle exhaust gas passing through the second measurement cell 50 is discharged through the outlet 60 (S260).

Meanwhile, as described above, a step of calibrating the zero point of the zirconia sensor and/or the non-dispersive infrared sensor using air may be further included. During zero point calibration, the connection from the solenoid valve 20 to the air inlet 70 is opened and the connection to the gas inlet 10 is closed. Also, as described above, a step of performing span calibration using the standard gas connected to the span calibration gas inlet 80 may be further included. The zero point calibration may be performed every time the concentration of vehicle exhaust gas is measured, performed at a certain number of times the concentration of vehicle exhaust gas is measured, or may be performed at regular time intervals. Span calibration can be performed at an appropriate number of times, for example, about once a month or once a week. Accuracy of the measured value of the concentration of exhaust gas can be improved by zero point calibration and span calibration.

10: gas inlet 12: main filter
20: electronic gas valve 22: zero filter
30: pump 40: first measuring cell
50: second measuring cell 51: zirconia sensor
52: cell housing 53: cell space
54 cell inlet 55 cell outlet
60: outlet 70: atmospheric inlet
80: span calibration gas inlet 81: check valve
100: vehicle emission measuring device

Claims (16)

a gas inlet through which vehicle exhaust gas flows;
an electronic gas valve connected to the gas inlet;
a pump assisting inflow of the vehicle exhaust gas;
A first measurement cell including a non-dispersive infrared gas sensor;
a second measuring cell including a zirconia sensor; and
a gas outlet through which the vehicle exhaust gas is discharged; are connected in sequence,
An atmospheric inlet through which atmospheric air is introduced is further connected to the electronic gas valve,
The electronic gas valve is a vehicle exhaust gas measuring device capable of selectively allowing or blocking the connection to the exhaust gas inlet and the atmospheric inlet. According to claim 1,
The first measurement cell is a vehicle exhaust gas measuring device for measuring the concentration of carbon monoxide, hydrocarbons and carbon dioxide. According to claim 1,
The second measuring cell is a vehicle exhaust gas measuring device for measuring the concentration of nitrogen oxides and oxygen. According to claim 1,
The second measuring cell is
the zirconia sensor;
a cell housing made of a heat-resistant material surrounding the zirconia sensor;
cell inlets and cell outlets located in opposite directions within the cell housing, through which the vehicle exhaust gas enters and exits; and
and a cell space between the zirconia sensor and the cell housing, in which the vehicle exhaust gas is filled. According to claim 4,
The cell space is 10 cm ³ or less vehicle exhaust gas measuring device. According to claim 4,
A vehicle exhaust gas measuring device in which the distance between the zirconia sensor and the cell housing is 1 cm or less. According to claim 4,
The cell housing is a vehicle exhaust gas measuring device made of Teflon (PTFE) or PEEK (polyether ether ketone). According to claim 1,
Further comprising a main filter disposed between the gas inlet and the pump, wherein the main filter includes a water removal filter for removing water and a dust removal filter for removing dust. According to claim 1,
An apparatus for measuring vehicle exhaust gas, further comprising a zero-point filter between the air inlet and the pump. According to claim 8,
Vehicle exhaust gas measuring device further comprising a pressure sensor between the main filter and the electronic valve. According to claim 1,
Further comprising a span calibration gas inlet located between the pump and the first measurement cell,
An apparatus for measuring vehicle exhaust gas into which the span calibration gas is introduced from the span calibration gas inlet. According to claim 1,
The temperature in the second measuring cell is in the range of 0 ° C to 100 ° C. Vehicle exhaust gas measuring device. According to claim 1,
The pressure in the second measuring cell is a method for measuring vehicle exhaust gas in the range of 0.5 atm to 2 atm. Claim 1 to claim 13, wherein any one of the vehicle emissions measuring device comprising: providing;
introducing vehicle exhaust gas into the vehicle exhaust gas measuring device through the gas inlet;
Measuring the concentrations of carbon monoxide, hydrocarbons and carbon dioxide in the introduced vehicle exhaust gas; and
Measuring the concentration of nitrogen oxides in the vehicle exhaust gas from which the concentrations of hydrocarbons and carbon dioxide are measured; Method for measuring vehicle exhaust gas comprising a. According to claim 14,
Performing zero point calibration of the non-dispersive infrared type gas sensor for hydrocarbons and carbon dioxide or zero point calibration of the zirconia sensor for nitrogen oxide using the air introduced from the air inlet before the vehicle exhaust gas is introduced. A method for measuring vehicle emissions further comprising: According to claim 14,
Span calibration of the non-dispersive infrared type gas sensor for hydrocarbon and carbon dioxide or span calibration of the zirconia sensor for nitrogen oxide using the span calibration gas introduced from the span calibration gas inlet before the vehicle exhaust gas is introduced. Method for measuring vehicle exhaust gas further comprising the step of performing.

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