Composite sensor for measuring dynamic temperature and pressure and preparation method thereof

Abstract

The invention discloses a composite sensor for measuring dynamic temperature and pressure and a preparation method thereof. The composite sensor comprises a sensor base, a temperature measuring unit and a pressure measuring unit, the temperature measuring unit comprises a metal shell and a ceramic-based thermocouple temperature measuring unit, a first mounting hole is formed in the metal shell, a second mounting hole is formed in the sensor base, the ceramic-based thermocouple temperature measuring unit is mounted in the first mounting hole, and the measuring end of the thermocouple temperature measuring unit protrudes out of the first end face of the sensor base. According to the invention, high-temperature airflow can simultaneously act on the film thermocouple sensitive body of the temperature measuring unit and the pressure sensitive body of the pressure measuring unit through the pressure guiding hole, so that synchronous measurement of dynamic temperature and gas pressure is realized; the measuring end of the galvanic couple temperature measuring unit protrudes out of the first end face of the sensor base, and the measuring end of the galvanic couple temperature measuring unit is exposed in the airflow, so that transient sensing of the airflow temperature is realized, and synchronous measurement of transient temperature and pressure is easier to realize.

Description

Technical Field

[0001] The present invention relates to the field of sensor design technology and measurement technology, and in particular to a composite sensor for measuring dynamic temperature and pressure and a preparation method thereof. Background Art

[0002] In some occasions where dynamic temperature and pressure information is obtained, such as aircraft surfaces or pressure pipe containers, timely and effective temperature and pressure data can effectively support the judgment of the safety and performance of related structures. In the dynamic temperature measurement of aircraft surfaces, the thermocouple wires can be distributed to measure the structural temperature and calculate the surface heat flow. At the same time, holes are opened on the surface to allow the airflow to flow to the pressure sensor to obtain its air pressure information. Similarly, in the acquisition of the temperature and pressure of the airflow pressure pipe, armored thermocouples or armored platinum resistance are used to obtain temperature information, and pressure sensors are used to obtain pressure information.

[0003] Among them, pressure measurement can be performed using silicon-based piezoresistive or adhesive strain pressure sensors. The dynamic response of pressure measurement can reach the microsecond level. However, at higher temperatures (greater than 200°C), adhesive strain pressure sensors will fail due to adhesive glue, and silicon-based piezoresistive pressure sensors will generate large leakage currents due to high temperatures, which will reduce the performance of the pressure sensor. For dynamic temperature measurement, the response time of wire thermocouples can be less than 1 second, while the response time of armored thermocouples is longer, so it is impossible to perform synchronous measurement of dynamic temperature and pressure.

[0004] At present, in the design of temperature and pressure composite measurement sensors, the first type is to integrate the temperature measurement unit on the circuit conditioning board of the pressure sensor. The temperature measurement here can be used to compensate for the temperature drift of the pressure signal and measure the ambient temperature inside the sensor. This type of temperature-pressure measurement sensor cannot measure the gas temperature. The second type is mostly to integrate the temperature measurement unit (platinum resistor) or thermocouple film with the piezoresistive sensitive unit on the same chip. Most of these sensors are silicon-based chips. They need to be filled with oil for use in pressure measurement. Due to the slow heat transfer in temperature measurement, the product cannot really measure the pressure and temperature synchronously, and it is difficult to use it for accurate measurement. The third type is to package the temperature measurement unit (platinum resistor) and the pressure sensitive unit in a combined manner. This type of composite measurement sensor generally packages and measures the armored platinum resistor temperature measurement unit and the pressure sensitive unit separately, but due to the armored structure of the platinum resistor, the dynamic response of the temperature measurement is still poor, and relatively synchronous measurement cannot be achieved in the dynamic temperature and pressure measurement.

[0005] Therefore, it is necessary to develop a composite sensor for measuring dynamic temperature and pressure and a preparation method thereof to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to design a composite sensor for measuring dynamic temperature and pressure and a preparation method thereof in order to solve the above problems.

[0007] The present invention achieves the above-mentioned purpose through the following technical solutions: Combined sensor for measuring dynamic temperature and pressure, including: Sensor base; The temperature measuring unit comprises a metal shell and a ceramic-based thermocouple temperature measuring unit. A first mounting hole is provided in the metal shell, a second mounting hole is provided in the sensor base, the ceramic-based thermocouple temperature measuring unit is installed in the first mounting hole, and a measuring end of the thermocouple temperature measuring unit protrudes from a first end surface of the sensor base; The pressure measuring unit comprises a metal substrate, an insulating layer and a resistance layer. The metal substrate is mounted on the first end face of the sensor base, the insulating layer is arranged above the metal substrate, and the resistance layer is arranged above the insulating layer.

[0008] A method for preparing a composite sensor for measuring dynamic temperature and pressure comprises the steps of: S1. Prepare a ceramic-based thermocouple temperature measurement unit: deposit metal thermoelectric material A and metal thermoelectric material B on two opposite sides of the ceramic substrate, respectively, and sputter ITO oxide on one end surface of the ceramic substrate to form an ITO film; connect two K-type compensation wires to the metal thermoelectric material A and the metal thermoelectric material B, respectively, to extract signals; S2. Prepare a temperature measurement unit: insert the ceramic-based thermocouple temperature measurement unit into the first mounting hole of the metal shell, and use ceramic adhesive to seal and fix the metal shell and the ceramic-based thermocouple temperature measurement unit, and then thread the metal shell with the second mounting hole; S3. Prepare a pressure measurement unit: prepare an insulating layer, a resistance layer, and a protective layer in sequence on a metal substrate, lead out the signal of the resistance layer through a pressure signal adapter board, and connect the metal substrate to the sensor base.

[0009] The beneficial effects of the present invention are: 1. The high-temperature airflow can simultaneously act on the thin-film thermocouple sensitive body of the temperature measuring unit and the pressure sensitive body of the pressure measuring unit through the pressure-introducing hole to realize the synchronous measurement of dynamic temperature and gas pressure; and in the present application, the measuring end of the thermocouple temperature measuring unit is protruded from the first end surface of the sensor base, and the measuring end of the thermocouple temperature measuring unit is exposed to the airflow, so as to realize the transient perception of the airflow temperature, and more easily realize the synchronous measurement of transient temperature and pressure; 2. The composite sensor is integrated with a temperature sensitive unit and a pressure sensitive unit, which is very convenient in sensor testing, calibration and use, and can realize modular combination of different specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 is a cross-sectional view of the present invention; Figure 3 It is a structural schematic diagram of the temperature measurement unit in the present invention; Figure 4 It is a structural schematic diagram of the ceramic-based thermocouple temperature measuring unit in the present invention; Figure 5 It is a structural schematic diagram of the pressure measurement unit in the present invention; Figure 6 Schematic diagram of the pressure strain resistance pattern of the resistance layer in the present invention.

[0011] Legend: 1-sensor base; 2-temperature measuring unit; 21-metal shell; 22-ceramic-based thermocouple temperature measuring unit; 221-ceramic substrate; 222-metal thermoelectric material A; 223-metal thermoelectric material B; 224-ITO film; 23-ceramic sealant; 3-pressure measuring unit; 31-metal substrate; 32-insulating layer; 33-resistance layer; 4-pressure signal adapter board; 5-welding point. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0013] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0015] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0016] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0017] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0019] like Figure 1 and 2 As shown in Figure 5, a composite sensor for measuring dynamic temperature and pressure comprises: Sensor base 1; The temperature measuring unit 2 comprises a metal shell 21 (made of 316L), a ceramic-based thermocouple temperature measuring unit 22, a first mounting hole is provided in the metal shell 21, a second mounting hole is provided in the sensor base 1, the ceramic-based thermocouple temperature measuring unit 22 is installed in the first mounting hole, and a measuring end of the thermocouple temperature measuring unit protrudes from the first end surface of the sensor base 1; Pressure measuring unit 3; the pressure measuring unit 3 comprises a metal substrate 31, an insulating layer 32, and a resistance layer 33 (a high-resistance nickel-chromium film strain bridge is prepared on the metal substrate 31 to achieve pressure measurement), the metal substrate 31 is mounted on the first end face of the sensor base 1, the insulating layer 32 is arranged above the metal substrate 31, and the resistance layer 33 is arranged above the insulating layer 32. The pressure measuring unit 3 is formed as a metal circular diaphragm structure with a diameter of 6 mm and a total thickness of 5 mm. The upper end faces of the temperature measuring unit 2 and the pressure measuring unit 3 are both arranged horizontally.

[0020] like Figure 2 and 3As shown, the temperature measurement unit 2 further includes a ceramic sealant 23 , and the ceramic sealant 23 is disposed between the metal housing 21 and the ceramic-based thermocouple temperature measurement unit 22 .

[0021] like Figure 4 As shown, the ceramic-based thermocouple temperature measuring unit 22 includes a ceramic substrate 221, a metal thermoelectric material A222, a metal thermoelectric material B223, and an ITO film 224 (the oxide has good oxidation resistance). The metal thermoelectric material A222 and the metal thermoelectric material B223 are respectively arranged on two opposite sides of the ceramic substrate 221, and the ITO film 224 is arranged on one end of the ceramic substrate 221 protruding from the first end face of the sensor base 1. The dimensions of the ceramic substrate 221 are: length: 10mm, width: 1.5mm, thickness: 0.3mm. The hot junction of the thermocouple is directly in contact with the airflow, which can achieve a dynamic response of the order of microseconds.

[0022] like Figure 2 and 3 As shown, the outer wall of the metal shell 21 is provided with an external thread, the second mounting hole of the sensor base 1 is provided with an internal thread, and the metal shell 21 is threadedly connected with the sensor base 1 .

[0023] like Figure 1 As shown, the first mounting hole is a rectangular mounting hole, and the ceramic substrate 221 is correspondingly a rectangular mounting hole. The mounting hole dimensions are: 2.5 mm in width, 3 mm in length, and 14 mm in height.

[0024] In some embodiments, the top of the ITO film 224 protrudes from the first end surface of the sensor base 1 by 0.5 mm.

[0025] like Figure 2 As shown, the composite sensor also includes two K-type compensation wires and a pressure signal adapter plate 4 . The two K-type compensation wires are respectively connected to the metal thermoelectric material A 222 and the metal thermoelectric material B 223 ; the resistance layer 33 is connected to the pressure signal adapter plate 4 .

[0026] A method for preparing a composite sensor for measuring dynamic temperature and pressure comprises the steps of: S1. Prepare a ceramic-based thermocouple temperature measuring unit 22: deposit metal thermoelectric material A222 and metal thermoelectric material B223 on two opposite sides of a ceramic substrate 221 by ion beam sputtering, and sputter ITO oxide on one end surface of the ceramic substrate 221 to form an ITO film 224; two K-type compensation wires are respectively connected to the metal thermoelectric material A222 and the metal thermoelectric material B223 for signal extraction; the metal thermoelectric material A222 is nickel-chromium, and the metal thermoelectric material B223 is nickel-silicon (K-type thermocouple); S2, preparing the temperature measurement unit 2: inserting the ceramic-based thermocouple temperature measurement unit 22 into the first mounting hole of the metal shell 21, and sealing and fixing the metal shell 21 and the ceramic-based thermocouple temperature measurement unit 22 with ceramic adhesive, and then welding and sealing the metal shell 21 and the second mounting hole after threading to ensure air tightness; S3, preparing the pressure measurement unit 3: preparing an insulating layer 32, a resistance layer 33, and a protective layer on the metal substrate 31 in sequence, leading out the signal of the resistance layer 33 through the pressure signal adapter plate 4, welding the metal substrate 31 to the sensor base 1, and welding the welding point 5 as shown in FIG. Figure 2 As shown, ensure airtightness.

[0027] like Figure 1 As shown, the overall appearance of the composite sensor is cylindrical, with a height of 40mm and a diameter of 25mm. The end of the sensor is designed to be connected with an external thread, so that the sensor can be easily installed at the airflow interface. The temperature measurement unit 2 in the composite sensor of the present application utilizes the small thermal capacity of the micron-level thermoelectric film. Through packaging, it can achieve direct contact with the airflow under pressure-sealed conditions, and can truly realize the transient measurement of the airflow temperature. The pressure measurement unit 3 in the composite sensor utilizes ion beam sputtering technology to prepare a high-insulation layer 32 film and a high-resistance strain film on a metal substrate 31, which can measure the high-temperature gas pressure greater than 200°C.

[0028] The metal substrate 31 is made of 17-4PH material, with a hole of 4mm in diameter in the middle, and the thickness of the circular membrane is 0.5mm. The composite silicon dioxide insulating layer 32 film and the high resistance nickel-chromium functional layer film are prepared on the metal substrate 31 by ion beam plating technology. Figure 6 As shown, it is the pressure strain resistor pattern, the power supply is V + and V - The power supply voltage is 10V, and the signal output is through S + and S - Measure the output voltage.

[0029] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A composite sensor for measuring dynamic temperature and pressure, characterized in that: include: Sensor base; The temperature measuring unit comprises a metal shell and a ceramic-based thermocouple temperature measuring unit. A first mounting hole is provided in the metal shell, a second mounting hole is provided in the sensor base, the ceramic-based thermocouple temperature measuring unit is installed in the first mounting hole, and a measuring end of the thermocouple temperature measuring unit protrudes from a first end surface of the sensor base; The pressure measuring unit comprises a metal substrate, an insulating layer and a resistance layer. The metal substrate is mounted on the first end face of the sensor base, the insulating layer is arranged above the metal substrate, and the resistance layer is arranged above the insulating layer.

2. The composite sensor for measuring dynamic temperature and pressure according to claim 1, characterized in that: The temperature measuring unit also includes ceramic sealant, which is arranged between the metal shell and the ceramic-based thermocouple temperature measuring unit.

3. The composite sensor for measuring dynamic temperature and pressure according to claim 1, characterized in that: The ceramic-based thermocouple temperature measuring unit includes a ceramic substrate, metal thermoelectric materials nickel-chromium, metal thermoelectric materials nickel-silicon, and an ITO film. The metal thermoelectric materials nickel-chromium and metal thermoelectric materials nickel-silicon are respectively arranged on two opposite sides of the ceramic substrate, and the ITO film is arranged on one end of the first end face of the ceramic substrate protruding from the sensor base.

4. The composite sensor for measuring dynamic temperature and pressure according to claim 1, characterized in that: An outer wall of the metal shell is provided with an external thread, and an inner thread is provided in the second mounting hole of the sensor base. The metal shell is thread-matched and connected with the sensor base.

5. The composite sensor for measuring dynamic temperature and pressure according to claim 3, characterized in that: The first mounting hole is a rectangular mounting hole, and correspondingly the ceramic substrate is a rectangular shape.

6. The composite sensor for measuring dynamic temperature and pressure according to claim 3, characterized in that: The top of the ITO film protrudes from the first end surface of the sensor base by 0.5 mm.

7. The composite sensor for measuring dynamic temperature and pressure according to claim 3, characterized in that: The composite sensor also includes two K-type compensation wires and a pressure signal adapter board. The two K-type compensation wires are respectively connected to the metal thermoelectric material A and the metal thermoelectric material B; and the resistance layer is connected to the pressure signal adapter board.

8. The method for preparing a composite sensor for measuring dynamic temperature and pressure according to any one of claims 1 to 7, characterized in that: Includes steps: S1. Prepare a ceramic-based thermocouple temperature measurement unit: deposit metal thermoelectric material A and metal thermoelectric material B on two opposite sides of the ceramic substrate, respectively, and sputter ITO oxide on one end surface of the ceramic substrate to form an ITO film; connect two K-type compensation wires to the metal thermoelectric material A and the metal thermoelectric material B, respectively, to extract signals; S2. Prepare a temperature measurement unit: insert the ceramic-based thermocouple temperature measurement unit into the first mounting hole of the metal shell, and use ceramic adhesive to seal and fix the metal shell and the ceramic-based thermocouple temperature measurement unit, and then thread the metal shell with the second mounting hole; S3. Prepare a pressure measurement unit: prepare an insulating layer, a resistance layer, and a protective layer in sequence on a metal substrate, lead out the signal of the resistance layer through a pressure signal adapter board, and connect the metal substrate to the sensor base.

9. The method for preparing a composite sensor for measuring dynamic temperature and pressure according to claim 8, characterized in that: Metal thermoelectric material A and metal thermoelectric material B are deposited on two opposite sides of the ceramic substrate by ion beam sputtering.

10. The method for preparing a composite sensor for measuring dynamic temperature and pressure according to claim 8, characterized in that: The metal shell is threadedly matched with the second mounting hole and then welded and sealed; the metal base is welded to the sensor base.

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