JPH1038849A - Measuring device for pm in exhaust gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new, useful PM measuring device and capable of quantitatively analyzing PM(particulate matter), contained in gas exhausted from an internal combustion engine such as a diesel engine, continuously with accuracy. SOLUTION: Gas G exhausted from an internal combustion engine 1 is analyzed in two flame ionization detectors 10, 11. The output of each detector is signal-processed to obtain THC(total hydrocarbon) concentration and soot concentration and to obtain a trend ratio in output signals of both detectors 10, 11. The THC concentration is multiplied by this ratio to obtain SOF(soluble organic fraction) concentration, thus obtaining SOF and PM concentration individually.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring PM in exhaust gas for quantitatively analyzing PM (Particulate Matter, particulate matter such as soot) contained in gas discharged from an internal combustion engine such as a diesel engine.

[0002] The PM is defined by the filter weight method as follows. That is, the engine exhaust gas is diluted with air to 52 ° C. or lower using a dilution tunnel, cooled, and collected on a filter using a fluorocarbon-coated glass fiber filter or a membrane filter capable of collecting 95% or more of 0.3 μm standard particles. The sum of the solid or liquid particles thus obtained is referred to as PM. And after collection, temperature 25 ℃,
The weight after being left in an atmosphere of 60% humidity for 8 hours or more is referred to as the weight of PM.

[0003] The PM is dissolved in an organic solvent and is mainly a hydrocarbon component such as SOF (Soluble Or).
ganic fraction) and ISF (Insol)
and the ISF includes dry soot (hereinafter, referred to as a carbon component) which is mainly a carbon component.
Soot), sulfate and moisture. For the measurement and analysis of PM, for example, Japanese Society of Mechanical Engineers (No. 95-29) training materials ('95.
6.1-2, Tokyo, Measuring technology for improving combustion and emission of internal combustion engines) "Measurement and analysis of particulate matter" [Japan Automotive Research Institute Hitoshi Yamazaki].

[0004]

2. Description of the Related Art By the way, the above-mentioned filter weight method uses P
The filter on which M has been attached and collected is measured using a precision balance, and so-called continuous measurement cannot be performed. On the other hand, as a method of continuously measuring PM in exhaust gas, there is a method disclosed in Japanese Patent Publication No. 2-31820. This PM measurement method irradiates a sample gas with light having a wavelength sensitive to HC (hydrocarbon) and light having a wavelength not sensitive to HC, measures the absorption of the sample gas, and obtains data obtained at that time. The amounts of SOF and Soot are calculated using mathematical expressions obtained by experience.

[0005] However, the PM measurement method disclosed in the above-mentioned publication has poor theoretical support and has a problem that it cannot be said that SOF or Soot is actually measured. In addition, the cell is easily contaminated and maintenance is troublesome. There are inconveniences.

On the other hand, there is a carbon balance method. The configuration of the PM measuring apparatus using the carbon balance method will be described with reference to FIG.

In FIG. 7, reference numeral 61 denotes a gas flow path through which exhaust gas (sample gas SG) from a diesel engine (not shown) flows, and is divided into two flow paths 63 and 64 at a point 62 on the downstream side. . One channel 63 is
A filter 66 having a built-in collection filter 65 for collecting PM in the sample gas SG and a heating combustion furnace 67 are provided, and are configured as a reference gas flow path. The other flow path 64 includes a dummy filter 68 having no filter for making the dead volume the same as the reference gas flow path 63, and a heating combustion furnace 69 configured similarly to the heating combustion furnace 67. And is configured as a sample gas flow path.

Numeral 70 denotes a fluid modulation type gas analyzer, which comprises a gas analyzer 71, a sample gas SG from the sample gas channel 64, and a reference gas RG from the reference gas channel 63 alternately in a fixed amount. And a gas supply unit 72 that supplies the gas at a time. That is, the gas analyzer 71 arranges the two cells 73 and 74 in parallel, and
The infrared light sources 75 and 76 are arranged on one side of each of the cells 4, and the CO ₂ detector 77 and the H _{2 formed of} , for example, a condenser microphone type detector are arranged on the other sides of the cells 73 and 74.
_{A 2} O detector 78 is optically arranged in series.

The gas supply section 72 is composed of, for example, a rotary valve. When a reference gas RG is supplied to one cell 73 by a partition plate 79 which is rotated by a motor (not shown), the other cell 74 is provided.
Is supplied with the sample gas SG, and one cell 73
When the sample gas SG is supplied to the other cell 74, the reference gas RG is supplied to the other cell 74.
The gas SG and the RG are switched and supplied at a constant cycle. 80 and 81 are a gas supply unit 72 and a cell 7
It is a gas flow path that connects between 3, 74.

The basic principle of the above-mentioned fluid modulation type gas analyzer is described in Japanese Patent Publication No. 56-48822 by the present applicant.
This is described in detail in the official gazette.

In the PM measuring apparatus having the above structure, a part of the sample gas SG flowing through the gas flow channel 61 is divided into a reference gas flow channel 63 at a point 62,
6, the contained PM is removed to become a reference gas RG and introduced into the heating and burning furnace 67. Then, the remaining sample gas SG is directly introduced into the heating combustion furnace 69 through the Dummy filter 68 as it is.

The insides of the heating and burning furnaces 67 and 69 are heated to, for example, about 1000 ° C., and CO and HC components are oxidized (burned) to become CO ₂ and H ₂ O. After that, the combustion gas in both gas passages 63 and 64 is supplied to the sample gas SG and the reference gas R
G is alternately supplied to the cells 73 and 74 alternately.

A light source 7 is provided to both cells 73 and 74.
By irradiating infrared light from 5, 73, cells 73,
The infrared light passing through the cell 74 undergoes a predetermined absorption in the cells 73 and 74, and then is subjected to the CO ₂ detector 77 and the H ₂ O detector 7.
8 is incident. At this time, the magnitude of the signal obtained from both detectors 77 and 78 is obtained as a difference that is proportional to CO ₂ and H ₂ O in sample gas SG and reference gas RG. That is, the CO ₂ detector 77
And the sum of the outputs of the H ₂ O detector 78 is the PM concentration.

[0014]

As described above, according to the carbon balance method, PM contained in exhaust gas from a diesel engine or the like can be continuously determined, but there are the following problems. . That is, the reference gas channel 63 and the sample gas channel 64
It is difficult to measure with high-speed response due to the noise caused by the flow resistance difference in. The measurement of CO ₂ and H ₂ O using infrared light has many interference components and is likely to cause errors. It is necessary to use two detectors 67, 68 in order to detect the two components of the CO ₂ and H ₂ O. The coexisting base gas is CO ₂ and H ₂
Since it is the same as O, it is difficult to increase the sensitivity.

Conventionally, HC such as total hydrocarbon (Total Hydro-Carbon, hereinafter referred to as THC) in a sample gas is quantitatively analyzed as shown in FIG.
Flame ionization detector (Frame Io)
A Detector 40 is known. That is, in FIG.
Reference numeral 41 denotes a combustion chamber, in which a nozzle 42 and a collector electrode 43 are provided. Reference numeral 44 denotes a sample gas supply path for supplying the sample gas S, and reference numeral 45 denotes a fuel gas supply path for supplying a fuel gas F composed of only hydrogen gas or hydrogen gas and another combustible gas. 4
The nozzles 4 and 45 are integrated on the upstream side of the nozzle 42 and
2 are connected. Reference numeral 46 denotes an auxiliary gas supply passage for supplying auxiliary air A, and an end of the auxiliary gas supply passage is opened and connected at an appropriate position in the combustion chamber 41.

The nozzle 42 is connected to a high-voltage DC power supply (not shown) via a high-voltage wiring 47, and the collector electrode 43 is connected to a signal processing circuit (not shown) via a signal line 48. ing. In addition, 49 is an ignition device provided above the inside of the combustion chamber 41, 50 is an exhaust port, and 51 is an insulating sleeve.

In the FID 40 having the above-described structure, for example, the sample gas S containing the HC component is introduced into the combustion chamber 41 together with the fuel gas F and the auxiliary air A, and the ignition device 49 generates, for example, a discharge spark. A desired flame 52 is formed at the tip of the nozzle 42, and this flame 52
The thermal energy of HC is generated by the energy of the sample gas S, and a current output proportional to the amount of HC contained in the sample gas S is generated by the signal line 48.
Through which the concentration of HC in the sample gas S can be analyzed.

As described above, PM contained in exhaust gas from a diesel engine mainly includes SOF, which is mainly a hydrocarbon component (HC), and Soo, which is mainly carbon component (C). According to the FID 30, it was not possible to detect a carbon component depending on the FID 30.

However, according to the study of the inventor of the present application, the FI which has been conventionally used for the analysis of the HC component is used.
It has been found that not only HC but also C (carbon) can be detected by D40.

FIG. 5 shows the combustion chamber 4 of the FID 40.
1 is a diagram for explaining a process of generating thermal ions in the nozzle 1. For example, the nozzle 42 is supplied with +30 by a high-voltage DC power supply 53 provided between the nozzle 42 and the collector electrode 43.
When a discharge spark is generated by the ignition device 39 in a state where the voltage of 0 V is applied, a high-temperature flame 52 of, for example, 1500 K is formed at the tip of the nozzle 42.

At this time, the inventors presume that Soot contained in the sample gas S containing carbon (graphite) as a main component is detected for the following reason. That is, under the high temperature as described above, the soot emits electrons by thermal energy and thermal ionization may be performed. At this time, the energy at which graphite is ionized is 4.5 eV (103.7 kcal / m).
ol). Originally, graphite has a specific resistance of 4
× 10 ⁻⁵ Ω · cm, which is a semiconductor, but is considered to be relatively easily charged graphite by receiving energy of the above magnitude. Then, it is estimated that the electrons emitted by the ionization are collected by the nozzle 42, so that graphite as a carbon component can be detected.

FIG. 6 shows an actual measurement example showing the responsiveness of the FID 40 to graphite.

The present invention has been made on the basis of the above-mentioned matters and knowledge, and is a novel method capable of continuously and accurately quantitatively analyzing PM contained in gas discharged from an internal combustion engine such as a diesel engine. It is an object of the present invention to provide a useful PM measuring device in exhaust gas (hereinafter, simply referred to as a PM measuring device).

[0024]

In order to achieve the above object, a PM measuring apparatus according to the present invention is provided in which a gas discharged from an internal combustion engine is branched to an upstream side and a downstream side of a gas flow path at a constant flow rate as a sample gas. Connecting the flow paths, while providing a first flame ionization detector and a second flame ionization detector in these branch flow paths, respectively, between the connection points of the two branch flow paths in the gas flow path, A gas introduction path for cooling the sample gas and a filter device for trapping PM contained in the cooled sample gas are provided, and a predetermined high-temperature exhaust gas is supplied to the first flame ionization detector. Supplying a sample gas substantially lower in temperature than the hot sample gas to a second flame ionization detector, and processing a signal obtained from the first flame ionization detector; Therefore, the THC concentration and the Soot concentration are determined, and the ratio of the trend in each output signal of the second flame ionization detector and the first flame ionization detector is determined. The ratio is multiplied by the THC concentration to obtain the SOF concentration. I want to ask.

When the sample gas (exhaust gas) held at 191 ° C. is measured by the first FID, THC and Soo
The total concentration with t is measured. When THC contained in the sample gas is cooled from the 191 ° C. to a considerably lower temperature (for example, 52 ° C.) and condensed, some of the THC changes to SOF. The rate of change k
(= SOF / THC) is approximately a function of the cooling temperature T. That is, the total amount TPM of PM is approximately expressed by the following equation (1). TPM (t) = Soot (t) + k (T) THC (t) (1) where (t) is a function of time (instantaneous value)
It is represented by.

To determine k (T) in the above equation (1), a difference between signals output from the respective FIDs when the sample gas before and after cooling is supplied to the first and second FIDs, respectively, is used. Since the generation of the SOF, that is, the cooling of the THC, requires a sufficient mixing of the sample gas, it can be made sufficiently slower than the response time of the FID and the state change of the internal combustion engine. Therefore, the trend <THC ₁ > (average over a sufficiently long time width) in the instantaneous value data before cooling the sample gas, that is, the instantaneous value data based on the output signal of the first FID, and the instantaneous value data after cooling the sample gas That is, the ratio of the instantaneous value data based on the output signal of the second FID to the trend <THC ₂ > is k (T). That is, k (T) = <THC ₁ > / <THC ₂ >.

According to the present invention, the PM concentration in the exhaust gas of a diesel engine or the like is determined by comparing the SOF component and the soot component.
Measurement can be performed simultaneously and at high speed (on the order of sub-milliseconds) in a state where components are distinguished.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an example of a PM measuring apparatus according to the present invention. In this figure, 1 is a diesel engine, 2 is an exhaust pipe connected to the diesel engine 1, and 3 is an exhaust pipe 2. A pump 4 for sucking exhaust gas G flowing through the exhaust pipe 2 into the sample gas flow path 3 at a predetermined constant flow rate is provided at a downstream end of the connected sample gas flow path.

Between the connection point 5 on the upstream side of the sample gas flow path 3 and the pump 4, two branch flow paths 6, 7 (hereinafter referred to as first branch flow path 6, The second branch flow path 7 is connected so that the probes 8 and 9 are inserted into the sample gas flow path 3, respectively. Each of the first branch channel 6 and the second branch channel 7 has the F
The FIDs 10 and 11 having the same configuration as the ID 40 (hereinafter referred to as the first
ID10 and a second FID11).

The first branch channel 6 of the sample gas channel 3
Cooling gas introduction pipe for introducing a cooling gas CG for cooling the exhaust gas G flowing downstream of the connection point of the first branch flow path 6 to a predetermined temperature between the first branch flow path 6 and the second branch flow path 7 12
Is connected. The cooling gas introduction pipe 12 is provided with a mass flow controller 13 for measuring a flow rate of the cooling gas CG and adjusting the flow rate to a predetermined flow rate. Reference numeral 14 denotes a cooling unit formed in the vicinity where the cooling gas introduction pipe 12 is connected. Reference numeral 15 denotes a filter device provided with a collection filter 16 for removing PM contained in the exhaust gas G cooled in the cooling unit 14.

The portion 17 from the connection point 5 on the upstream side of the sample gas flow path 3 to the cooling / mixing section 12 on the downstream side and the first branch flow path 6 are formed by appropriate temperature control means (not shown). The temperature of the exhaust gas G flowing through them is controlled to be 191 ° C. At this temperature, the exhaust gas G
The SOF contained therein is almost gas. Such exhaust gas G is supplied to the _first FID 10 via the probe 8 and the first branch channel 6 as the sample gas S1.

The exhaust gas G that has reached the cooling section 14 via the temperature control section 17 comes into contact with a clean, low-temperature cooling gas CG such as air or nitrogen gas introduced through the cooling gas introduction pipe 12, and contacts the cooling gas CG. Cooled by mixing, 52 ° C
It is adjusted to become. Therefore, the cooling gas CG supplied to the cooling unit 14 via the cooling gas introduction pipe 12 is:
The temperature is adjusted to a predetermined value and the cooling gas introduction pipe 12
The flow rate is adjusted by the mass flow controller 13 provided in the apparatus.

The portion 18 from the cooling section 14 of the sample gas flow path 3 to the connection point of the second branch flow path 7 and the second branch flow path 7 are formed by appropriate temperature control means (not shown). The temperature of the exhaust gas G flowing through is controlled so as to be 52 ° C. At this temperature, the SOF contained in the exhaust gas G is adsorbed on the PM. Such exhaust gas G is supplied as a sample gas S2 to the _second FID 11 via the probe 9 and the second branch channel 8 via the filter device 15.

19 and 20 are the first FID 10 and the second FID
11 signal output lines, the preamplifiers 21 and
2 is provided. Reference numeral 23 denotes, for example, an analog signal processing device to which the output signals a and b of the first FID 10 and the second FID 11 that have passed through the preamplifiers 21 and 22 are input.

FIG. 2 shows an example of the configuration of the signal processing device 23. Reference numeral 24 denotes a comparator, 25 and 26 denote smoothing circuits such as a moving average circuit, 27 denotes a subtraction circuit, 28 denotes a division circuit, and 29 denotes a multiplication circuit. The circuit 30 is an addition circuit. 31 to 32 are output points.

The operation of the PM measuring apparatus configured as described above will be described with reference to FIGS. FIG.
As shown in the figure, the diesel engine 1 flowing through the exhaust pipe 2
Exhaust gas G containing PM discharged from the sample gas is sucked into the sample gas flow path 3 by a certain amount by the suction operation of the pump 4,
Exhaust gas G having a constant flow rate flows through the sample gas flow path 3, and a part of the exhaust gas G is taken into the first branch flow path 6 via the probe 8 as the sample gas S ₁ at 191 ° C. This is in the sample gas S _1, SOF is included as a gas, as described above.

The sample gas S ₁ is supplied to the first FID 10
As shown in FIG. 4, a desired flame 52 is formed at the tip of the nozzle 42 by an ignition device 49, and the flame 5
Thermal energy ionization of HC occurs with the energy of FIG.
Is output to the output signal line 19 as shown in FIG.

In the signal a, the portion a ₁ that changes slowly is called a trend, which is a signal corresponding to THC (including a portion that changes to SOF) contained in the sample gas S ₁ , shot noise-like portion a ₂ is a signal corresponding to Soot contained in the sample gas S _1.

[0040] Among those taken as a sample gas S ₁ of the first branch flow channel 6 to 191 ° C., the sample gas S ₁ that has reached the cooling unit 14 is supplied to the cooling unit 14 via a cooling gas inlet tube 12 that is cooled by contact with the cooling gas CG, the sample gas S ₂ whose temperature adjusted to the 52 ° C.. As described above, in this sample gas S _2,
SOF is adsorbed on PM. Then, the sample gas S ₂ is, when passing through the filter device 15, PM contained in it (SOF and Soot) are removed, PM
The sample gas S ₂ next free state, a portion is taken as a sample gas S ₂ of 52 ° C. to the second branch flow channel 7 through the probe 9.

The sample gas S ₂ is supplied to the second FID 11
In the same manner as in the first FID 10, a desired flame 52 is formed at the tip of the nozzle 42 by the ignition device 49, and thermal energy of HC is generated by the energy of the flame 52, as shown in FIG. The signal b is output to the output signal line 20.

In the signal b, the slowly changing trend b ₁ is included in the sample gas S _2.
This is a signal corresponding to HC (SOF has been removed).

The outputs a and b of the first FID 10 and the second FID 11 are input to a signal processing device 23 as shown in FIG. In the signal processing device 23, for example, the following signal processing is performed.

First, the signal a is supplied to the comparator 24,
It is input to the moving average circuit 25 and the subtraction circuit 27. The comparator 24 has a function of determining the shot noise based on the rising speed and the height. The comparator 24 controls the density component c corresponding to the signal component a ₂ of the signal a corresponding to Soot.
[= Soot (t)] is obtained. The signal c is input to the subtraction circuit 27 and the addition circuit 30 and is output to the output point 31 as a signal representing the soot (t).

The moving average circuit 25 detects a trend a _{1 in} which the signal a changes gradually and separates the trend a ₁ , and outputs a signal d [= <THC ₁ >>]. The signal is input to the division circuit 28.

On the other hand, the signal b is output from the moving average circuit 2
5, is input to a moving average circuit 26 having the same function as
The signal e [= <THC ₂ >>] from the moving average circuit 26
Is output, and this signal e is input to the division circuit 28.

Then, in the subtraction circuit 27, the difference between the signal a and the signal c is obtained. That is, THC (t) contained in the exhaust gas G at a temperature of 191 ° C. before cooling is obtained, and this is input to the multiplying circuit 29 as a signal f.

In the division circuit 28, e /
An operation of d, that is, an operation of <THC ₂ > / <THC ₁ > is performed, a coefficient k (T) is obtained, and the coefficient k (T) is input to the multiplication circuit 28 as a signal g.

In the multiplication circuit 28, the amount of THC (t) contained in the exhaust gas G at a temperature of 191 ° C. before cooling is multiplied by a coefficient k (T) to obtain SOF (t). This SOF (t) is used as the signal h as the signal h.
, And is output to an output point 32 as a signal representing SOF (t).

In the addition circuit 30, the output c [= Soot (t) of the comparator 24 and the output h [= SOF (t)] of the multiplication circuit 29 are added, and TPM (t) which is the total concentration of PM is obtained. Is obtained, and a signal i representing this is output to the output point 33 as.

That is, TPM (t),
Soot (t) and SOF (t) can be obtained separately.

As understood from the above description, of the two FIDs 10 and 11, the components such as THC and soot contained in the exhaust gas G are instantaneously measured from the first FID 10 on the upstream side, while the first FID 10 on the downstream side is measured. The 2FID 11 is used for signal compensation. Therefore, only the first FID 10 needs to measure the amount related to the response, and the two FIDs 10, 1
Despite using 1, there is sufficient responsiveness,
Measurement in the sub-millisecond order is possible.

Then, the output signal a from the first FID 10
By performing signal processing according to the characteristics of the signal to obtain a signal corresponding to Soot,
The generation of OF is regarded as a function of temperature, and the ratio of the trend <THC ₂ > in the exhaust gas G at 52 ° C. to the trend <THC ₁ > in the exhaust gas G at 191 ° C. is determined as k (T), and the phase change from THC to SOF is performed. Since the amount to be performed is determined quantitatively, the concentration of each component can be determined accurately.

In the above-described embodiment, the sample pipe 3 for sampling the exhaust gas G at a constant flow rate is connected to the exhaust pipe 2 connected to the diesel engine 1. , 11 is introduced, but this is not always necessary. For example, the sample gas is caused to flow through the exhaust pipe 2 at a constant flow rate, and the FID 1
Exhaust gas G may be introduced into the exhaust pipes 0 and 11, and a dilution tunnel for diluting the exhaust gas G is connected to the exhaust pipe 2, and a constant flow sampling device (Constant Vo) is connected to the tunnel.
lume sampler) may be provided to introduce the diluted exhaust gas G into the FIDs 10 and 11.

In the above-described embodiment, the signal processing device 23 is configured as an analog system. However, the present invention is not limited to this. The signal processing device 23 may be configured as a digital system. A computer may be used as the signal processing device 23.

[0056]

As described above, according to the present invention, the PM concentration in the exhaust gas from an internal combustion engine such as a diesel engine can be quantitatively analyzed continuously, simultaneously and accurately with distinction between Soot and SOF. .

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an example of a configuration of a PM measurement device of the present invention.

FIG. 2 is a diagram schematically showing an example of a signal processing device used in the PM measuring device.

FIG. 3 is an explanatory diagram of an operation of the PM measuring device.

FIG. 4 is a diagram showing an example of a flame ionization detector used in the present invention.

FIG. 5 is a diagram for explaining a process of generating thermal ions in a combustion chamber of the flame ionization detector.

FIG. 6 is a view showing an actual measurement example showing responsiveness to graphite in the flame ionization detector.

FIG. 7 is a diagram for explaining a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 3 ... Gas flow path, 6, 7 ... Branch flow path, 10
... First hydrogen flame ionization detector, 11 second flame ionization detector, 12 cooling gas inlet pipe, 15 filter device, 23 signal processing device, G exhaust gas, S, S ₁ , S ₂
... sample gas, c ... Sot concentration, i ... SOF concentration,
i: PM concentration.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yutaka Yamagishi 2 Higashi-cho, Kichijoin-gu, Minami-ku, Kyoto, Kyoto Inside Horiba, Ltd.

Claims (1)

[Claims] 1. A branch flow path is connected to an upstream side and a downstream side of a gas flow path through which a gas discharged from an internal combustion engine flows at a constant flow rate as a sample gas, and a first flow path is connected to these branch flow paths.
A gas flame ionization detector and a second gas flame ionization detector are provided, respectively, and a gas introduction path and cooling for cooling the sample gas are provided between the connection points of the two branch flow paths in the gas flow path. A filter device for trapping PM contained in the sample gas is provided, a predetermined high-temperature exhaust gas is supplied to the first flame ionization detector, and a second sample gas having a considerably lower temperature than the high-temperature sample gas is supplied to the second flame ionization detector. The THC concentration and the Soot concentration are obtained by supplying the signal to the flame ionization detector and processing the signal obtained from the first flame ionization detector, and the second flame ionization detector and the first flame ionization detector Is obtained by multiplying the ratio by the above-mentioned THC concentration.
P in exhaust gas characterized by obtaining concentration
M measuring device.