Thermal conductivity detection cell body of integrated organic element analyzer

Abstract

The utility model provides an integrated organic element analyzer thermal conductivity detection cell body, which comprises a main body cell, a thermistor and a signal conditioning part, and the signal conditioning part is used for converting a resistance signal of the thermistor into a voltage or current signal; the device further comprises a data acquisition board and a driving part, the data acquisition board is arranged in the main body pool through a supporting column, the driving part provides voltage for the signal conditioning part to work, the thermistor, the signal conditioning part and the driving part are all fixed to the data acquisition board and electrically connected with the data acquisition board, and the data acquisition board is provided with an electrical interface. The driving component and the thermistor are integrated on one circuit board, so that the distance between the driving component and the thermistor is reduced, and coupling of external interference is reduced.

Description

Technical Field

[0001] This application relates to the field of elemental analysis, and more specifically, to an integrated organic elemental analyzer thermal conductivity detection cell. Background Technology

[0002] Organic elemental analyzers are used to measure the content of carbon, hydrogen, nitrogen, sulfur, and oxygen in samples. When a gas containing carbon, hydrogen, nitrogen, or sulfur passes through a thermal conductivity detector, the detector outputs a voltage signal that changes over time. The area of ​​this signal is proportional to the content of the corresponding element. By measuring the area, the content of the corresponding element can be obtained.

[0003] The core device for detecting substances in an organic elemental analyzer is a thermal conductivity detector, and the core device of the thermal conductivity detector is a thermal conductivity detection cell with a thermistor. The principle of its detection is as follows: different gases have different thermal conductivity coefficients. When a gas passes through the thermal conductivity detector cell, it carries away some of the heat from the thermistor, causing a change in the temperature of the thermistor, which in turn causes a change in the resistance of the thermistor. When the current flowing through the thermistor is constant, the change in resistance will produce a change in voltage. By measuring and recording the voltage value, the content of different gases can be determined.

[0004] Existing thermal conductivity detection cells are relatively simple, generally consisting of only one cell and two thermistors. The thermistors are connected to a remote circuit board via connecting wires. The thermistor driving circuit is separate from the thermal conductivity detection cell. Since the driving signal is an analog signal, it is very susceptible to interference when transmitted through wires, generating additional noise. This leads to increased noise in the driving signal at both ends of the thermistor and can also couple into the measurement circuit. Utility Model Content

[0005] The purpose of this application is to provide an integrated organic element analyzer thermal conductivity detection cell to solve the signal interference problem existing in the prior art.

[0006] An integrated organic element analyzer thermal conductivity detection cell is provided, including a main cell, a thermistor, and a signal conditioning component. The main cell is provided with an air inlet and an air outlet. The thermistor is used to detect the gas temperature in the main cell. The signal conditioning component is used to convert the resistance signal of the thermistor into a voltage or current signal. It also includes a data acquisition board and a driving component. The data acquisition board is mounted on the main cell via a support column. The signal conditioning component operates by being powered by the driving component. The thermistor, signal conditioning component, and driving component are all fixed to and electrically connected to the data acquisition board. The data acquisition board is provided with an electrical interface.

[0007] In one alternative embodiment, an onboard temperature sensor for detecting the ambient temperature of the thermistor is also included, which is powered by a driving component and is fixed to and electrically connected to the data acquisition board.

[0008] In one optional embodiment, a sensitivity switching component is further included. The sensitivity switching component is connected to the signal conditioning component for controlling the intensity of the output signal of the analyte. The sensitivity switching component is fixed to and electrically connected to the data acquisition board.

[0009] In one optional embodiment, the thermistor includes a working gas thermistor and a reference gas thermistor, the air inlet includes a working gas inlet and a reference gas inlet, the working gas thermistor and the reference gas thermistor are used to detect the working gas temperature and the reference gas temperature in the main tank, respectively; the onboard temperature sensor is located between the working gas thermistor and the reference gas thermistor.

[0010] In one optional embodiment, the system further includes an analog-to-digital converter (ADC) connected to a signal conditioning unit for converting analog voltage signals into digital signals, the ADC being fixed to a data acquisition board.

[0011] In one optional embodiment, the device further includes a thermistor voltage adjustment component, which is used to adjust the output ratio of the working gas thermistor voltage and the reference gas thermistor voltage, and the thermistor voltage adjustment component is fixed on the data acquisition board.

[0012] In one optional embodiment, a thermistor operating parameter storage component is further included. The thermistor operating parameter storage component is used to store thermistor parameter data and is fixed on the data acquisition board.

[0013] In one optional embodiment, a main tank temperature sensor is also included, which is fixed to the bottom of the main tank by screws.

[0014] In one optional embodiment, both the working gas thermistor and the reference gas thermistor are vertically arranged, with one end located in the main pool and the other end extending out of the data acquisition board and fixed to the data acquisition board by welding.

[0015] In one optional embodiment, the signal conditioning component includes a first operational amplifier, a second operational amplifier, and an instrumentation amplifier. The non-inverting input of the first operational amplifier is connected to a working gas thermistor and a driving component, and the inverting input is connected to the output. The output is connected to the inverting input of the instrumentation amplifier and a digital-to-analog converter via a voltage divider resistor. The non-inverting input of the second operational amplifier is connected to a reference gas thermistor and a driving component, and the inverting input is connected to the output. The output is connected to a thermistor voltage adjustment component, and the output signal of the thermistor voltage adjustment component is connected to the non-inverting input of the instrumentation amplifier and the digital-to-analog converter. The two gain setting resistor pins of the instrumentation amplifier are connected to a sensitivity switching component, which provides different resistance values ​​to the instrumentation amplifier by switching. The output of the instrumentation amplifier is connected to the digital-to-analog converter.

[0016] This application integrates the driving component and the thermistor onto a single circuit board, reducing the distance between them and minimizing the coupling of external interference. Integrating the signal conditioning component, analog-to-digital converter, and thermistor onto a single circuit board further reduces the distance between them and minimizes the coupling of external interference. Optimizing the circuit board layer and wiring design further minimizes measurement noise; converting analog signals to digital signals before transmitting them to the remote controller improves the signal's anti-interference capability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a perspective view of the thermal conductivity detection cell of an integrated organic element analyzer provided in an embodiment of this application.

[0019] Figure 2 This is a side view of the thermal conductivity detection cell of an integrated organic element analyzer provided in an embodiment of this application.

[0020] Figure 3 This is a top view of the thermal conductivity detection cell of an integrated organic element analyzer provided in an embodiment of this application.

[0021] Figure 4 This is a schematic diagram of a thermistor detection circuit for an integrated organic element analyzer thermal conductivity detection cell, provided in an embodiment of this application.

[0022] Figure 5This is a circuit diagram of the driving component of the thermal conductivity detection cell of an integrated organic element analyzer provided in an embodiment of this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise defined, the technical or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art. The words "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are only used to distinguish different components. The words "comprising" or "including," etc., mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but do not exclude other elements or objects. The words "connected," "coupled," or "connected," etc., are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up," "down," "left," "right," etc., are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0024] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application. Furthermore, the embodiments and features in the embodiments of this application can be combined with each other without conflict.

[0025] Figure 1-3 The integrated organic element analyzer thermal conductivity detection cell provided in this application embodiment includes a main cell 1, a thermistor, and a signal conditioning component 9. The main cell is provided with an air inlet and an air outlet 20. The thermistor is used to detect the gas temperature in the main cell 1; the signal conditioning component is used to convert the resistance signal of the thermistor into a voltage or current signal. In addition, it also includes a data acquisition board 2 and a driving component. The data acquisition board 2 is mounted on the main cell 1 via a support column 3. The signal conditioning component 9 operates by being supplied with voltage by the driving component. The thermistor, signal conditioning component, and driving component are all fixed to and electrically connected to the data acquisition board. The data acquisition board is provided with an electrical interface 4.

[0026] An onboard temperature sensor 16 for detecting the ambient temperature of the thermistor is also provided. It operates by being powered by a driving component and is fixed to and electrically connected to the data acquisition board 2. Furthermore, a sensitivity switching component 19 is provided, connected to a signal conditioning component to adjust the sensitivity of the thermistor. This sensitivity switching component is also fixed to and electrically connected to the data acquisition board. Figure 4 As shown, the sensitivity switching component 19 includes a relay and resistors R22 and R24. Different blocking signals are provided to the signal conditioning component 9 via relay switching. The relay can be a model HFD4-V / 12-SR relay. The sensitivity switching component, using relay switching, is used to adjust the intensity of the output signal of the analyte, thereby modifying the sensitivity without requiring hardware changes and reducing the possibility of errors.

[0027] The thermistors include a working gas thermistor 7 and a reference gas thermistor 13. The air inlets include a working gas inlet 5 and a reference gas inlet 6. The working gas thermistor 7 and the reference gas thermistor 13 are used to detect the working gas temperature and the reference gas temperature in the main tank, respectively. An onboard temperature sensor 16 is located between the working gas thermistor and the reference gas thermistor. By properly positioning a temperature sensor, the operating ambient temperature of both thermistors can be measured. Both the working gas thermistor 7 and the reference gas thermistor 13 are vertically arranged, with one end located in the main tank and the other end extending out of the data acquisition board and fixed to the data acquisition board by welding.

[0028] It also includes an analog-to-digital converter (ADC) 11, which is connected to the signal conditioning unit 9 to convert analog voltage signals into digital signals. The ADC is fixed on the data acquisition board. Converting the analog signal to a digital signal before transmitting it to the remote controller improves the signal's anti-interference capability. The ADC can use the AD7190BRUZ chip manufactured by Analog Devices. It is a high-precision, low-noise ADC, particularly suitable for thermocouples and other applications requiring high-resolution signal processing.

[0029] It also includes a thermistor voltage adjustment component 18, which is used to adjust the output ratio of the working gas thermistor voltage and the reference gas thermistor voltage. The thermistor voltage adjustment component 18 is fixed to the data acquisition board. Figure 4 As shown, the main component is a digital potentiometer, model TPL0401A-10DCKR, whose resistance value can be adjusted via an I²C interface. When used in conjunction with a thermistor, it can perform various functions, primarily for temperature measurement, compensation, and control applications.

[0030] In addition, a thermistor operating parameter storage component 8 is included. This component, fixed to the data acquisition board, stores thermistor parameter data. This effectively solves the problem of mismatch between stored thermistor parameters and the actual thermistor. The storage component and the thermistor are integrated into a single unit, and the stored parameters correspond to the specific thermistor. After replacing the thermistor, the corresponding parameters are modified, and the parameters are directly read when using the device, thus preventing mismatch errors.

[0031] It also includes a main tank temperature sensor 17, which is fixed to the bottom of the main tank with screws. This tight fixing with screws allows for accurate acquisition of the main tank temperature.

[0032] like Figure 4 As shown, the signal conditioning unit includes a first operational amplifier U5A, a second operational amplifier U5B, and an instrumentation amplifier U8. Both the first operational amplifier U5A and the second operational amplifier U5B are high-precision, low-noise dual-channel operational amplifiers, model LMP7702, manufactured by Texas Instruments. The instrumentation amplifier U8 is a high-precision instrumentation amplifier, model AD623BR, manufactured by Analog Devices. The non-inverting input of the first operational amplifier U5A is connected to the working gas thermistor and driving component of the cell, and the inverting input is connected to the output. The output is connected to the inverting input of the instrumentation amplifier U8 and the digital-to-analog converter through a voltage divider resistor. The non-inverting input of the second operational amplifier U5B is connected to the reference gas thermistor and driving component, and the inverting input is connected to the output. The output is connected to the thermistor voltage adjustment component, and the output signal of the thermistor voltage adjustment component is connected to the non-inverting input of the instrumentation amplifier U8 and the digital-to-analog converter. The two gain setting resistor pins (RG pins) of the instrumentation amplifier U8 are connected to the sensitivity switching component, which provides different resistance values ​​to the instrumentation amplifier through a switch. The output of the instrumentation amplifier is connected to the digital-to-analog converter.

[0033] In this embodiment, the driving component comprises three parts: a working gas thermistor driving component 10, a reference gas thermistor driving component 14, and an onboard temperature sensor driving component 15, corresponding to the working gas thermistor 7, the reference gas thermistor 13, and the onboard temperature sensor 16, respectively. The three parts have essentially the same structure. Figure 5 This is the circuit schematic of the driving component.

[0034] Integrating the drive component and thermistor onto a single circuit board reduces the distance between them and minimizes the coupling of external interference. Optimizing the circuit board layer and wiring design further minimizes interference noise. This effectively addresses the issue of high measurement signal noise and poor anti-interference capability. By integrating the signal conditioning component, analog-to-digital converter, and thermistor onto a single circuit board, the distance between them is reduced, minimizing the coupling of external interference. Optimizing the circuit board layer and wiring design further minimizes measurement noise. Converting the analog signal to a digital signal before transmitting it to the remote controller improves the signal's anti-interference capability.

[0035] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims in this application and their equivalents, then this application also intends to include these modifications and variations.

[0036] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

Claims

1. An integrated organic elemental analyzer thermal conductivity detection cell body, comprising a main cell, a thermistor and a signal conditioning component; the main cell is provided with a gas inlet and a gas outlet; the thermistor is used to detect the temperature of the gas in the main cell; the signal conditioning component is used to convert the resistance signal of the thermistor into a voltage or current signal; characterized in that Further comprising a data acquisition board and a driving component, the data acquisition board is arranged on the main cell through a support column, the signal conditioning component is provided with voltage work by the driving component, the thermistor, the signal conditioning component and the driving component are fixed on the data acquisition board and electrically connected thereto, and the data acquisition board is provided with an electrical interface.

2. The integrated organic elemental analyzer thermal conductivity cell body of claim 1, wherein: Further comprising a board temperature sensor for detecting the ambient temperature of the thermistor, which is provided with voltage work by the driving component, and the board temperature sensor is fixed on the data acquisition board and electrically connected thereto.

3. The integrated organic elemental analyzer thermal conductivity cell body of claim 1, wherein: Further comprising a sensitivity switching component connected to the signal conditioning component for the output signal intensity of the measured substance, the sensitivity switching component is fixed on the data acquisition board and electrically connected thereto.

4. The integrated organic elemental analyzer thermal conductivity cell body of claim 2, wherein: The thermistor comprises a cell body working gas thermistor and a reference gas thermistor, the gas inlet comprises a cell body working gas inlet and a cell body reference gas inlet, the cell body working gas thermistor and the reference gas thermistor are used to detect the working gas temperature and the reference gas temperature in the main cell respectively; the board temperature sensor is located at the intermediate position of the working gas thermistor and the reference gas thermistor.

5. The integrated organic elemental analyzer thermal conductivity cell body of claim 4, wherein: Further comprising an analog-to-digital converter connected to the signal conditioning component for converting the analog voltage signal into a digital signal, the analog-to-digital converter is fixed on the data acquisition board.

6. The integrated organic elemental analyzer thermal conductivity cell body of claim 5, wherein: Further comprising a thermistor voltage zeroing component for adjusting the working voltage output ratio of the working gas thermistor and the reference gas thermistor, the thermistor voltage zeroing component is fixed on the data acquisition board.

7. The integrated organic elemental analyzer thermal conductivity cell body of claim 6, wherein: Further comprising a thermistor working parameter storage component for storing thermistor parameter data, which is fixed on the data acquisition board.

8. The integrated organic elemental analyzer thermal conductivity cell body of claim 1, wherein: Further comprising a main cell temperature sensor fixed on the bottom of the main cell by a screw.

9. The integrated organic elemental analyzer thermal conductivity cell body of claim 5, wherein: The cell body working gas thermistor and the reference gas thermistor are vertically arranged, one end is located in the main cell, the other end extends out of the data acquisition board and is fixed on the data acquisition board by welding.

10. The integrated organic elemental analyzer thermal conductivity cell body of claim 7, wherein: The signal conditioning component includes a first operational amplifier, a second operational amplifier and an instrument amplifier, the non-inverting input terminal of the first operational amplifier is connected with the pool body working gas thermal resistance and the driving component, the inverting input terminal is connected with the output terminal, the output terminal is connected with the inverting input terminal of the instrument amplifier and the digital-analog converter through the voltage dividing resistor; the non-inverting input terminal of the second operational amplifier is connected with the reference gas thermal resistance and the driving component, the inverting input terminal is connected with the output terminal, the output terminal is connected with the thermal resistance voltage zero adjustment component, the output signal of the thermal resistance voltage zero adjustment component is connected with the non-inverting input terminal of the instrument amplifier and the digital-analog converter; the two gain setting resistor pins of the instrument amplifier are connected with the sensitivity switching component, the sensitivity switching component provides different resistance values to the instrument amplifier through the switch; the output terminal of the instrument amplifier is connected with the digital-analog converter.

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