CN102081070B - Carbon nano tube film three-electrode acetylene sensor and concentration measuring method thereof - Google Patents

Abstract

The invention discloses a carbon nanotube film three-electrode acetylene sensor and a concentration measurement method thereof, wherein the sensor comprises a first electrode, a second electrode and a third electrode which are sequentially distributed, the first electrode is provided with air holes, and the inner surface of the first electrode is bonded with a substrate distributed with a carbon nanotube film; the center of the second electrode is provided with a lead-out hole; a blind hole is formed in the surface of the third electrode; the three electrodes are isolated from each other. The method comprises the following steps: 1) the acetylene sensors with different inter-polar distances, the temperature sensors and the humidity sensors are placed in acetylene gas to be detected; 2) applying a voltage across the electrodes; 3) measuring ion flow values of the sensors; 4) the measured values and acetylene concentration, temperature and humidity calibration values form a sample, and the sample and an interpolation sample construct an acetylene concentration measurement database; 5) constructing a data fusion instrument and establishing an acetylene concentration measurement model; 6) and inputting the actual measurement value of the sensor into the measurement model to obtain the accurate acetylene concentration measurement value. The sensor has high sensitivity, good linearity and high accuracy in acetylene measurement.

Description

Carbon nanotube film three-electrode acetylene sensor and its concentration measurement method

technical field

The invention relates to the field of gas sensing, in particular to a three-electrode acetylene sensor based on carbon nanotube film and gas discharge principle and a method for measuring acetylene concentration.

Background technique

With the urgent need of gas measurement in all walks of life and the development of nanotechnology, nanosensors have made great progress. Especially with the discovery of carbon nanotubes at the end of the 20th century, carbon nanotubes have shown attractive application prospects in the fields of gas, temperature and humidity measurement. The thin-film two-electrode sensor among carbon nanotube gas, temperature, and humidity sensors has become a research hotspot in the field of gas, temperature, and humidity measurement due to its high measurement sensitivity, wide gas range, and fast response. Carbon nanotube film two-electrode gas sensor is based on the principle of gas discharge, which overcomes the shortcomings of other types of carbon nanotube gas sensors that are saturated and poisoned in the measured gas, and has a wider gas concentration measurement range and a wider range of gas types to be measured. Gas-sensitive, temperature-sensitive, and humidity-sensitive sensors made of carbon nanotubes as sensitive materials have irreplaceable advantages of conventional sensors: First, carbon nanotubes have a large specific surface area, which can greatly improve the overall size of the sensor when the overall size of the sensor is small. The area of the electrode; the second is based on the nanoscale tip curvature radius of the carbon nanotubes, which greatly reduces the operating voltage of the sensor, and obtains a very strong electric field strength near the tip of the carbon nanotubes, ionizing the measured gas at a low voltage; The size of the sensor is greatly reduced, and the dynamic response is fast. Therefore, it has broad development prospects in biology, chemistry, machinery, aviation, military affairs, and anti-terrorism.

Existing carbon nanotube film two-electrode sensors include carbon nanotube film two-electrode sensors disclosed by professors Liu Junhua, Zhang Yong, Li Xin, Zhu Changchun, etc. of Xi'an Jiaotong University at the 14th IVMC International Vacuum Microelectronics International Conference in 2001. Electrode gas sensor (shown in Figure 1). After the sensor works, because the space charge is difficult to diffuse after the discharge between the electrodes, the sensor is difficult to return to the initial state, and the breakdown voltage, breakdown current and gas concentration of the sensor show a multi-valued relationship (Figure 2, Figure 3), and the gas concentration cannot be measured. Concentration is measured. Professor Nikhil Koratkar and Pulickel M Ajayan of Rensselaer Polytechnic Institute in the United States developed a carbon nanotube film anode two-electrode gas sensor. The breakdown voltage of the sensor shows a nonlinear relationship with the gas concentration, and the linear error between the breakdown discharge current and the gas concentration is large; the discharge voltage and discharge current are large; and the carbon nanotube thin film anode cannot measure a single gas. Professor Hui Guohua and Professor Chen Yuquan from the School of Biomedical Engineering and Instrument Science of Zhejiang University developed a carbon nanotube film cathode two-electrode gas sensor under the condition of 120 micron electrode spacing, and studied the discharge characteristics of the sensor in three single gases , due to low sensitivity, does not constitute a gas sensor for measuring concentration.

Therefore, the current research on carbon nanotube thin film electrode sensors sensitive to various single gases including acetylene and the method for measuring the concentration of acetylene gas has become a technical problem to be solved urgently.

Contents of the invention

One of the purposes of the present invention is to provide a carbon nanotube thin film three-electrode acetylene sensor, which divides the output current of the traditional carbon nanotube thin film two-electrode sensor into electron flow and ion flow, and establishes the collector of the three-electrode acetylene sensor of the present invention. The single-value corresponding relationship between ion flow and acetylene concentration, temperature, and humidity overcomes the multi-value nonlinear problem of carbon nanotube film two-electrode sensor gas-sensing characteristics and humidity-sensing characteristics. The sensor has the advantages of simple structure, low cost and high sensitivity for measuring gas.

Another object of the present invention is to provide a method for measuring acetylene concentration based on a carbon nanotube film three-electrode acetylene sensor; a sensor array composed of carbon nanotube film three-electrode sensors with different pole spacings measures the acetylene concentration, temperature and humidity to be measured respectively ; The hardware structure required by the concentration measurement method is simple, and the data fusion algorithm is adopted to measure the gas with high accuracy.

The purpose of the present invention is achieved through the following technical solutions.

The carbon nanotube film three-electrode acetylene sensor is characterized in that it includes three first electrodes, second electrodes and third electrodes distributed sequentially from top to bottom, and the first electrode is bonded with carbon nanotubes distributed on the inner surface. The substrate of the tube film and the electrode with air holes; the second electrode is composed of the lead-out plate with the lead-out hole in the center; the third electrode is composed of the collector with the blind hole on the plate surface; the three electrodes are respectively passed through The insulating posts are isolated from each other.

Structural feature of the present invention is also in:

The distance between two adjacent electrodes among the three electrodes is 30-250 μm;

The facing area of the first electrode and the second electrode plate is 0.01-17 mm ² , and the facing area of the second electrode and the third electrode plate is 0.01-190 mm ² .

The first electrode has 1 to 4 air holes on the electrode surface, and a carbon nanotube film is attached to the substrate bonded to the inner surface of the electrode;

The center of the second electrode lead-out pole is provided with 1 to 4 lead-out holes;

The collector blind hole of the third electrode corresponds to the lead-out hole of the second electrode, and the number of blind holes is 1-4.

The present invention also provides a method for measuring acetylene concentration based on a carbon nanotube film three-electrode acetylene sensor, the method comprising the following steps:

(1) Select a carbon nanotube film three-electrode sensor with the electrode spacing of two adjacent electrodes in the three electrodes set to 30-250 μm;

(2) Place the carbon nanotube film three-electrode acetylene sensor, the carbon nanotube film three-electrode temperature sensor and the carbon nanotube film three-electrode humidity sensor with three different electrode spacings in the atmosphere containing the acetylene gas to be measured. ;

(3) Applying a voltage of 0V to the first electrode of the carbon nanotube film acetylene sensor, a temperature sensor and a humidity sensor of three three-electrode structures respectively, the loading voltage of the second electrode is 2-200V, and the loading voltage of the third electrode is 1-180V;

(4) within the measurement range of acetylene concentration to be measured, temperature and humidity, corresponding to different concentration, temperature and humidity calibration values, measure the gas discharge ion current values output by all sensors in step (2) respectively;

(5) All the sensor output ion current values measured in the concentration, temperature and humidity measurement ranges in step (4) are combined with the corresponding acetylene concentration, temperature and humidity calibration values to form different experimental calibration samples, and then use Segment interpolation technology interpolates the experimental calibration samples to obtain interpolation data and interpolation samples, and builds the acetylene concentration measurement database based on all samples including the experimental calibration samples and interpolation samples;

(6) Using data fusion technology, build a data fusion instrument, establish the measurement model of acetylene sensor, temperature sensor and humidity sensor; use the data in the acetylene concentration measurement database as the input sample and expected output sample of the data fusion instrument, and use the measurement range The different data in the data fusion instrument are respectively used as training samples and inspection samples for training and inspection of the data fusion instrument. When the inspection results meet the actual measurement error requirements, the data fusion instrument outputs an accurate measurement model of the concentration of the acetylene sensor;

(7) Input the ion current value output by the carbon nanotube film three-electrode acetylene sensor, the temperature sensor and the humidity sensor into the accurate measurement model of the acetylene concentration obtained in step (6), and the model outputs the accurate measurement value of the acetylene concentration.

The inventive method is also characterized in that:

In the carbon nanotube film sensor with the three-electrode structure, the potential of the second electrode is higher than that of the first electrode, and the potential of the third electrode is lower than the potential of the second electrode and higher than that of the first electrode.

The establishment of the acetylene concentration measurement database is to form a database with experimental calibration data and interpolation data, use the ion current value output by each sensor and its interpolation data as input samples, and use the acetylene concentration, temperature and humidity calibration values and their interpolation data as expected output sample.

Based on the method of measuring acetylene concentration with carbon nanotube thin film three-electrode acetylene sensor, the sensor array is composed of carbon nanotube thin film three-electrode sensors with different electrode spacing to measure the concentration of acetylene, temperature and humidity respectively; powered by sensor voltage source; powered by pA level current The measurement system detects the output of the sensor; adjusts the electrode spacing, adjusts the electrode voltage, and performs the sensor calibration experiment in the temperature and humidity environment in the acetylene to be tested; interpolates the experimental calibration data based on the segmental interpolation technology to obtain the interpolation data; will include All the data of the experimental calibration data and interpolation data constitute the acetylene concentration measurement database, and the single-value gas-sensing characteristics, single-value temperature-sensing characteristics, and single-value humidity-sensing characteristics of acetylene are obtained; according to the data in the acetylene concentration measurement database, based on data fusion technology , to eliminate the influence of temperature and humidity, and establish an accurate concentration measurement model of the acetylene sensor; input the output of the sensor array during the actual measurement into the acetylene concentration measurement model in real time, and the actual measurement result of the acetylene concentration can be obtained. The acetylene concentration measurement method overcomes the multi-valued non-linear problem of the carbon nanotube film two-electrode sensor's gas-sensing characteristics and humidity-sensing characteristics, requires a simple hardware structure and low cost, and has high sensitivity and high accuracy for measuring acetylene gas, which is suitable for Promotional use.

The acetylene concentration measurement method of the invention can realize the concentration measurement of acetylene with an accuracy of 1%. Compared with the concentration measurement method of the traditional three-electrode detector used in the existing ionization detector chromatograph, the new acetylene concentration measurement method has high sensitivity to acetylene and a 1% concentration due to the use of carbon nanotube films as electrodes. Concentration measurement accuracy. In addition, the carbon nanotube film three-electrode sensor can reduce the working voltage of the sensor from the high voltage of 600 volts of the ionization detector to a safe and practical range below 200 volts with the tip curvature radius of the carbon nanotube nanoscale. The novel acetylene concentration measurement method of the present invention integrates sensor array technology with different pole spacing, pA level current measurement technology, segmental interpolation technology and data fusion technology, can eliminate the influence of temperature and humidity, and can realize accurate measurement of acetylene concentration .

Description of drawings

Fig. 1 is a schematic diagram of the structure of a carbon nanotube film cathode two-electrode sensor.

Fig. 2 shows the multi-valued nonlinear gas sensing characteristics of the breakdown voltage and gas concentration of the carbon nanotube film two-electrode gas sensor in the prior art.

Fig. 3 is the non-linear multi-valued gas sensing characteristics of the breakdown current and gas concentration of the carbon nanotube film two-electrode gas sensor in the prior art.

Fig. 4 is the structural representation of carbon nanotube film three-electrode acetylene sensor of the present invention;

Fig. 5 is a side view of the stereoscopic structure of the carbon nanotube film three-electrode acetylene sensor of the present invention.

Fig. 6 is the single-value relationship between the gas discharge ion current and the gas concentration output by the carbon nanotube film three-electrode acetylene sensor in acetylene of the present invention.

In the figure: 1, the first electrode; 2, the second electrode; 3, the third electrode; 4, the electrode provided with air holes; 5, the carbon nanotube film substrate; 6, the carbon nanotube film; 7, the insulating support.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Example 1

As shown in Fig. 4 and Fig. 5, the carbon nanotube thin film three-electrode acetylene sensor comprises three electrodes stacked from top to bottom in sequence, and the three stacked electrodes are respectively provided with a first electrode 1, a second electrode 1, and a second electrode 1. Electrode 2 and the third electrode 3, its first electrode 1 is bonded with the base 5 that distributes carbon nanotube thin film 6 and the electrode 4 that is provided with vent hole by inner surface and is made of; The third electrode 3 is composed of a collector with blind holes on the surface of the electrode plate; the three electrodes are separated from each other by insulating pillars 7 .

In the embodiment of the carbon nanotube film three-electrode acetylene sensor shown in Figure 4, there are 2 vent holes on the electrode surface of the first electrode 1, and the vent holes are circular; one side surface of the vent holes is bonded with carbon nanometer The tube film substrate 5 is distributed with a carbon nanotube film 6, and the carbon nanotube tube mouth is downward. A lead-out hole is provided in the center of the second electrode 2, and the lead-out hole is circular. The collector blind hole of the third electrode 3 corresponds to the lead-out hole of the second electrode. Fig. 4 and Fig. 5 show an embodiment in which a blind hole is provided and the blind hole is a cylindrical structure. The insulating pillars 7 are respectively arranged between the carbon nanotube film substrate 5 and the second electrode 2, and between the second electrode 2 and the third electrode 3, that is, the insulating pillars 7 are distributed on the carbon surface of the second electrode 2 facing the first electrode 1. The two sides of the surface of both ends of the nanotube film substrate and the two sides of the inner surface of the third electrode 3 .

The present invention is provided with the plate surface of the electrode 4 with vent holes and the carbon nanotube film substrate 5 all adopts silicon sheet material to make; Described carbon nanotube film 6, can adopt iron phthalocyanine as catalyst, and adopt carbon source, in The carbon nanotube film 6 is grown on the tube film substrate 5, or the carbon nanotube film 6 is screen-printed. Both the second electrode 2 and the third electrode 3 are made of silicon wafers. Metal films are provided on the inner surfaces of the electrode 4 and the third electrode 3 provided with air holes, and on both sides of the second electrode 2 .

There are 2 air holes on the electrode in the first electrode 1 of the present invention, which is convenient for the gas to be measured to enter the electrode gap; the silicon chip substrate of the carbon nanotube film has conductivity, and is firmly bonded to the inner surface of the first electrode; The extraction hole of the electrode 2 and the collector of the third electrode 3 can collect the positive ion flow generated by gas ionization. Between the first electrode 1 and the second electrode 2, between the second electrode 2 and the third electrode 3 are isolated from each other by insulating pillars 7; the gas to be measured enters the gap between two adjacent electrodes of the sensor through the gap between the peripheral electrodes of the sensor .

When the carbon nanotube film three-electrode acetylene sensor with the above structure measures the acetylene concentration, the potential of the second electrode is higher than the potential of the first electrode, and the potential of the third electrode is lower than the potential of the second electrode and higher than the potential of the first electrode. The second electrode forms an electron flow loop with the first electrode, and the third electrode forms an ion flow loop with the first electrode, so as to separate the electron flow from the ion flow. The relationship between the ion current output by the carbon nanotube film three-electrode acetylene sensor and the concentration of acetylene, temperature, and humidity presents a single-valued relationship on the basis of a certain voltage applied to the second electrode (Figure 6). Through segmental interpolation and data fusion, the measurement accuracy of acetylene concentration is 1%. The carbon nanotube film three-electrode sensor array technology with different pole spacing, pA level current measurement technology, segmental interpolation technology and data fusion technology are the characteristics of the concentration measurement method of the present invention.

The method for measuring the concentration of acetylene by the carbon nanotube film three-electrode acetylene sensor of the present invention will be further described through a specific example.

Using a carbon nanotube thin-film three-electrode acetylene sensor with a fixed pole spacing, the single-value gas-sensing characteristics of a single gas acetylene were experimentally obtained (as shown in Figure 6). A single gas acetylene concentration measurement with an accuracy of less than 1%.

In the example of measuring acetylene concentration by the carbon nanotube film three-electrode acetylene sensor shown in FIG. 6 , the experimental environment conditions are temperature 26.5°C, relative humidity 23.0%RH, and atmospheric pressure 93.7KPa. The distance between the first electrode 1 and the second electrode 2 of the sensor, and the distance between the second electrode 2 and the third electrode 3 are all 200 μm; the distance between the adjacent electrodes of the carbon nanotube film three-electrode sensor for monitoring temperature is 170 μm; The carbon nanotube thin-film three-electrode sensor for humidity has an electrode spacing of 200 μm and 100 μm between adjacent electrodes, respectively. In the three carbon nanotube film three-electrode sensors, the facing area of the first electrode 1 and the second electrode 2 is 17 mm ² , and the facing area of the second electrode 2 and the third electrode 3 is 190 mm ² . The cathode voltage of the first electrode 1 of the acetylene sensor is 0V, the loading voltage of the second electrode 2 is 80V, and the loading voltage of the third electrode 3 is 10V; the voltage of the first, second, and third electrodes of the temperature sensor is 0V, 70V, and 10V respectively ; The voltages of the first, second and third electrodes of the humidity sensor are 0V, 90V and 10V respectively. As the concentration of acetylene increases, the ion flow collected by the collector decreases, and the relationship between the ion flow and the concentration of acetylene shows a single value decrease; the sensitivity characteristics of temperature and humidity sensors are similar to those of acetylene sensors. In the range of 0-30ppm acetylene concentration, 13 sets of experimental calibration data were obtained. The ion current values of the three sensors are used as input samples, and the calibration value of acetylene concentration is used as the expected output sample data. Using linear interpolation to interpolate 13 sets of experimental calibration sample data, interpolating with a step size of 0.2ppm in the range of 0-30ppm acetylene concentration, obtaining 151 sets of interpolation data, and forming a database with 13 sets of experimental calibration data; selecting 151 sets of interpolation data A total of 152 sets of data and 1 set of experimental calibration data are used as training samples, 12 sets of experimental calibration data different from training samples and 1 set of experimental calibration data that have been used as training samples, a total of 13 sets of experimental calibration data are used as test samples, and input data fusion instrument , through training and testing, a single gas acetylene concentration measurement model is obtained. The linearity of the single-gas acetylene concentration measurement model is 0.09%, and the maximum quoted error of the test results of the 13 groups of test samples is 0.25%, reaching a single-gas acetylene concentration measurement accuracy of 1%.

Example 2

The basic structure of this embodiment is the same as that of Embodiment 1, except that the distance between two adjacent electrodes in the three electrodes of the carbon nanotube film three-electrode acetylene sensor is 250 μm and 30 μm respectively, and the first electrode 1 and the second electrode The facing area of the second electrode ² and the third electrode 3 is 0.01 mm ² .

There is one vent hole on the electrode surface of the first electrode 1, and the vent hole is quadrilateral, pentagonal or hexagonal; the second electrode 2 has 4 center lead-out holes, and the lead-out holes are quadrilateral, pentagonal or hexagonal ; The number of blind holes in the third electrode 3 is 4, and the blind holes are 3-6 prisms or pyramids.

The detection method of the present embodiment is basically the same as embodiment 1, the difference is:

The cathode voltage of the first electrode of the sensor is 0V, the lead-out pole of the second electrode is loaded with a voltage of 2V, and the collector of the third electrode is loaded with a voltage of 1V.

Example 3

The basic structure of this embodiment is the same as that of Embodiment 1, except that the distance between two adjacent electrodes in the three electrodes of the carbon nanotube film three-electrode acetylene sensor is 250 μm and 30 μm respectively, and the first electrode 1 and the second electrode The facing area of the second electrode ² and the third electrode 3 is 10mm ² .

There are 4 vent holes on the electrode surface of the first electrode 1, and the vent holes are quadrilateral, pentagonal or hexagonal; the second electrode 2 has 2 central lead-out holes, and the lead-out holes are quadrilateral, pentagonal or hexagonal ; The number of blind holes in the third electrode 3 is 2, and the blind holes are 3-6 prisms or pyramids.

The detection method of the present embodiment is basically the same as embodiment 1, the difference is:

The cathode voltage of the first electrode of the sensor is 0V, the lead-out electrode of the second electrode is loaded with a voltage of 200V, and the collector of the third electrode is loaded with a voltage of 180V.

In the present invention, a sensor array is composed of carbon nanotube thin film three-electrode sensors with different pole spacings, a pA level current measurement system measures sensor output, segmental interpolation and data fusion methods to form a new type that can measure acetylene gas, has strong anti-interference ability and is accurate Highly accurate acetylene concentration measurement method. Sensors with different pole spacing in the sensor array can measure the interference effect of temperature and humidity in real time, and directly measure the concentration of acetylene; the pA level current measurement system can simultaneously measure the pA level current output by each sensor corresponding to the gas concentration, temperature and humidity of each component; Segmental interpolation and data fusion methods can eliminate temperature and humidity interference, and output high-accuracy acetylene concentration measurement values.

Although the present invention has been described in detail with the above preferred embodiments, the above embodiments are not intended to limit the present invention. Without departing from the technical features and structural scope provided by the technical solution of the present invention, any addition, deformation or replacement of the technical features with the same content in the field shall belong to the protection scope of the present invention.

Claims (5)

1. carbon nano-tube film three electrode acetylene sensors, it is characterized in that: comprise three the first electrode, the second electrode and third electrodes that distribute successively from top to bottom, the electrode that described the first electrode is bonded with the substrate of the carbon nano-tube film that distributing by inside surface and is provided with bleeder vent consists of; The second electrode is made of the extraction pole pole plate that the center is provided with fairlead; Third electrode is made of the collector that the plate face is provided with blind hole; These three electrodes are isolated mutually by insulation column respectively.

2. carbon nano-tube film three electrode acetylene sensors according to claim 1, it is characterized in that: the die opening of adjacent two electrodes is 30～250 μ m in described three electrodes; Described the first electrode and the second electrode pad are 0.01～17mm over against area ², the second electrode and third electrode pole plate are 0.01～190mm over against area ²

3. carbon nano-tube film three electrode acetylene sensors according to claim 1, it is characterized in that: the bleeder vent of the electrode surface of described the first electrode is 1～4, is attached with carbon nano-tube film in the bonding substrate of the first electrode inner surface;

Described the second electrode extraction pole center is provided with 1～4 fairlead;

Described third electrode collector blind hole is corresponding with the fairlead of the second electrode, and the quantity of blind hole is 1～4.

4. measure the method for concentration of acetylene based on carbon nano-tube film three electrode acetylene sensors as claimed in claim 1, it is characterized in that the method comprises the steps:

(1) select the die opening of adjacent two electrodes in three electrodes to be set as carbon nano-tube film three electrode acetylene sensors of 30～250 μ m;

Carbon nano-tube film three electrode acetylene sensors of three different poles spacings (2) will setting respectively, carbon nano-tube film three electrode temperature sensors and carbon nano-tube film three electrode humidity sensors are placed in the atmosphere that contains acetylene gas to be measured;

(3) be 0V to the first electrode on-load voltage of carbon nano-tube film three electrode acetylene sensors, carbon nano-tube film three electrode temperature sensors and the carbon nano-tube film three electrode humidity sensors of three three-electrode structures respectively, the second electrode on-load voltage 2～200V, third electrode on-load voltage 1～180V;

(4) in concentration of acetylene to be measured, temperature and humidity measurement range, corresponding different concentration, temperature and humidity calibration value, respectively the gas discharge ion flow valuve of all the sensors output in the measuring process (2);

(5) with all the sensors output ion flow valuve that in concentration, temperature and humidity measurement range, records in the step (4), with corresponding concentration of acetylene, temperature and humidity calibration value, form different experimental calibration samples, then adopt the piecewise interpolation technology that the experimental calibration sample is carried out interpolation, obtain interpolated data, obtain interpolated sample, and set up the concentration of acetylene measured database according to all samples that comprised experimental calibration sample and interpolated sample;

(6) adopt Data fusion technique, make up the data fusion instrument, set up the measurement model of acetylene sensor, temperature sensor and humidity sensor; With input sample and the desired output sample of the data in the concentration of acetylene measured database as the data fusion instrument, and train and check as training sample and the test samples of data fusion instrument respectively with data different in the range ability, when assay satisfies the measurement error requirement, the concentration Measurement accuracy model of data fusion instrument output acetylene sensor;

The concentration of acetylene Measurement accuracy model that the ion flow valuve input step (6) of output obtains during (7) with carbon nano-tube film three electrode acetylene sensors, carbon nano-tube film three electrode temperature sensors and the actual measurement of carbon nano-tube film three electrode humidity sensors, the Measurement accuracy value of this model output concentration of acetylene;

In the carbon nano-tube film sensor of described three-electrode structure, the second electrode potential is higher than the first electrode potential, and the third electrode current potential is lower than the second electrode potential and is higher than the first electrode potential.

5. the method for measuring concentration of acetylene based on carbon nano-tube film three electrode acetylene sensors according to claim 4, it is characterized in that: the described concentration of acetylene measured database of setting up, that experimental calibration data and interpolated data are formed database, with each sensor output ion flow valuve and interpolated data thereof as the input sample, with concentration of acetylene, temperature and humidity calibration value and interpolated data thereof as the desired output sample.

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