Hot film anemograph

Abstract

The utility model discloses a hot film anemograph which comprises a detection element, a signal converter and a signal processor. The detection element at least comprises a group of carbon nano tube films, and the carbon nano tube films are thin films made of a carbon nano tube material of which the resistance value changes along with the temperature change; the signal converter amplifies the resistance change signal of the carbon nanotube film output by the detection element to obtain an amplified signal; and the signal processor processes the amplified signal output by the signal converter. According to the hot film anemograph disclosed by the embodiment of the invention, the sensitivity of the hot film anemograph is improved by improving the hot film in the detection element, and a worker can obtain more accurate reference data for calculating the wind speed according to a processing result of an amplified signal.

Description

Technical Field

[0001] The present application relates to the field of measurement technology, and more specifically, to a hot film anemometer. Background Art

[0002] The hot film anemometer is an instrument for measuring air velocity. It uses the characteristic that the resistance of the hot film in the hot film anemometer changes with temperature to measure the cooling effect of the fluid in the airflow on the thermal sensor, and then calculates the air velocity. However, the hot film of the hot film anemometer currently has the problem of low sensitivity, which leads to low measurement accuracy and slow response speed. Utility Model Content

[0003] In view of this, the present application provides a hot film anemometer for solving the problem of low sensitivity of the hot film in the existing hot film anemometer.

[0004] In order to achieve the above objectives, the proposed solution is as follows:

[0005] On one hand, the present application provides a hot film anemometer, comprising: a detection element, a signal converter and a signal processor;

[0006] The detection element comprises at least one group of carbon nanotube films, wherein the carbon nanotube films are thin films of carbon nanotube materials whose resistance value changes with temperature;

[0007] The detection element is used to output a resistance change signal of the carbon nanotube film, the output end of the detection element is connected to the input end of the signal converter, and the signal converter is used to amplify the resistance change signal to obtain an amplified signal;

[0008] The output end of the signal converter is connected to the input end of the signal processor, and the signal processor is used to process the amplified signal output by the signal converter.

[0009] In a possible implementation, the detection element further includes at least: a support structure for fixing the edge of the carbon nanotube film and laying the carbon nanotube film flat.

[0010] In a possible implementation, the support structure at least includes: a base and a top cover, and at least two support rods are fixedly connected to the edge of the base, and the support rods are used to support the top cover;

[0011] Wherein, two sides of the carbon nanotube film are respectively fixed to the two support rods.

[0012] In a possible implementation, the method further includes: a display connected to the output end of the signal processor, and configured to display a processing result of the signal processor on the amplified signal.

[0013] In a possible implementation, the method further includes: a communication module connected to the output end of the signal processor, and configured to send the processing result of the signal processor on the amplified signal to the output end.

[0014] The carbon nanotube film in the thermal film anemometer disclosed in the present application is a film of carbon nanotube material whose resistance value changes with temperature. The thermal film anemometer is placed in an airflow, and the heated carbon nanotube film contacts the airflow. The carbon nanotube film loses heat with the flowing airflow, causing its own temperature to change, thereby causing a change in its own resistance. The resistance change signal of the carbon nanotube film can contain information representing the wind speed, and by processing the amplified resistance change signal, reference data for calculating the wind speed can be obtained. Among them, the thermal sensitivity of the carbon nanotube film far exceeds that of the metal film, and the thickness of the carbon nanotube film with the same thermal sensitivity is much smaller than that of the metal film, which greatly improves the sensitivity of the thermal film anemometer, and even the resistance change signal caused by the slight heat change of the carbon nanotube film can be captured in time.

[0015] The hot film anemometer disclosed in this embodiment improves the sensitivity of the hot film anemometer by improving the hot film in the detection element. The staff can obtain more accurate reference data for calculating the wind speed based on the processing results of the amplified signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of the structure of a hot film anemometer is provided for an embodiment of the utility model;

[0018] Figure 2 A schematic diagram of the structure of a detection element provided in an embodiment of the utility model;

[0019] Figure 3 A schematic structural diagram of another detection element provided in an embodiment of the utility model.

[0020] Reference numerals:

[0021] 10-detection element; 20-signal converter; 30-signal processor; 100-carbon nanotube film; 200-pad; 300-support rod; 400-base; 500-top cover. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood in specific circumstances. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions without contradictions or conflicts, all within the scope of protection required by the utility model.

[0023] Reference Figure 1 , an embodiment of the utility model provides a structural schematic diagram of a hot film anemometer. The hot film anemometer proposed in the present application includes: a detection element 10, a signal converter 20 and a signal processor 30.

[0024] The detection element 10 at least includes a group of carbon nanotube films and a heating element. The heating element is used to heat the carbon nanotube film. The carbon nanotube film is a film of carbon nanotube material whose resistance value changes with temperature.

[0025] The detection element 10 is used to output a resistance change signal of the carbon nanotube film. The output end of the detection element 10 is connected to the input end of the signal converter 20. The signal converter 20 is used to amplify the resistance change signal to obtain an amplified signal.

[0026] The output end of the signal converter 20 is connected to the input end of the signal processor 30 , and the signal processor 30 is used to process the amplified signal output by the signal converter 20 .

[0027] The thermal film in the hot film anemometer usually uses a metal film. The thinner the metal film, the higher the sensitivity of the hot film anemometer. However, when the thickness of the thermal film made of metal or alloy reaches the micron level or even smaller, the metal film is easy to break, and the process of making ultra-thin metal film is relatively complicated, resulting in the low sensitivity of existing hot film anemometers.

[0028] The thermal film in the hot film anemometer proposed in the present application uses a carbon nanotube film. The carbon nanotube film is extracted from a carbon nanotube array and has a thickness of only tens of nanometers. In addition, the carbon nanotube film has a low heat capacity, which makes the thermal sensitivity of the carbon nanotube film far greater than that of the metal film. Using the carbon nanotube film as the thermal film of the hot film anemometer can improve the sensitivity of the hot film anemometer.

[0029] When using a hot film anemometer, the carbon nanotube film is heated by a heating element or an additional voltage, and the temperature of the carbon nanotube film rises, so that the resistance value of the carbon nanotube film is stabilized at a fixed value. Under the action of the airflow, that is, wind, flowing through the carbon nanotube film, the carbon nanotube film will transfer heat to the surrounding fluid and dissipate its own heat, which will cause the temperature of the carbon nanotube film to change, and then the resistance value of the carbon nanotube film will also change accordingly.

[0030] The detection element 10 sends the resistance change signal of the carbon nanotube film to the signal converter 20, and the signal converter 20 amplifies the resistance change signal. Further, the signal processor 30 processes the amplified resistance change signal, and obtains data related to the flow rate of the fluid flowing through the carbon nanotube film and causing the resistance value of the carbon nanotube film to change by analyzing the resistance change and temperature change of the carbon nanotube film per unit time, that is, data related to the wind speed, so as to provide the tester with a data basis for calculating the wind speed.

[0031] In addition, due to the flow direction of the fluid, i.e. the wind direction, the area of ​​the carbon nanotube film contacting the fluid is different, or the temperature changes of different parts of the carbon nanotube film are different, so the detection element 10 collects the resistance change signal of each position point of the carbon nanotube film, and the signal converter 20 amplifies it. The signal processor 30 can analyze the flow direction of the fluid, i.e. the wind direction, from the amplified resistance change signal of each position point. Therefore, the hot film anemometer provided in this embodiment can also realize the test of wind direction.

[0032] Reference Figure 2 , a schematic diagram of the structure of a detection element provided by an embodiment of the utility model, the detection element may include: a support structure for fixing the edge of the carbon nanotube film 100 and paving the carbon nanotube film 100.

[0033] The supporting structure may be two identical pads 200, which are respectively fixed at the two ends of the probe part of the detection element 10, and the two pads 200 are respectively fixed on both sides of the carbon nanotube film 100 so that it is laid flat on the probe part of the detection element.

[0034] It is understandable that the carbon nanotube film 100 needs to be laid flat on the probe portion of the detection element so that the fluid flows through the entire carbon nanotube film 100 , thereby collecting the resistance change signal generated by the carbon nanotube film 100 during the entire fluid flow process.

[0035] In one possible implementation, refer to Figure 3 , a schematic diagram of the structure of another detection element provided by an embodiment of the utility model, the support structure of the detection element 10 may include: a base 400 and a top cover 500, and at least two support rods 300 are fixedly connected to the edge of the base 400, and the support rods 300 are used to support the top cover 500; wherein, the two sides of the carbon nanotube film 100 are respectively fixed to the two support rods 300.

[0036] In order to maintain the stability of the base 400 and the top cover 500, at least three support rods 300 need to be fixed on the base 400. Any two of the support rods 300 are respectively fixed to the two opposite sides of the carbon nanotube film 100, so that the carbon nanotube film 100 is vertically laid between the base 400 and the top cover 500, so that fluid in any direction can flow through the carbon nanotube film 100, thereby obtaining wind speed related data in the measured environment.

[0037] In addition, if the detection element 10 is a test tool held by a tester, a handheld handle can be installed at either end of the base 400 or the top cover 500 to facilitate handheld testing by the tester.

[0038] Furthermore, the hot film anemometer may also include: a display connected to the output end of the signal processor 30, for displaying the processing result of the signal processor on the amplified signal.

[0039] In another possible implementation, the hot film anemometer may further include: a communication module connected to the output end of the signal processor 30, and configured to send the processing result of the signal processor 30 on the amplified signal to the output end.

[0040] It can be understood that the purpose of the signal processor 30 processing the amplified signal is to obtain data related to wind speed for reference by the tester. Therefore, this embodiment can feedback the test results to the tester through a display or communication module to improve the visibility of the test results of the thermal film anemometer.

[0041] In summary, the carbon nanotube film in the thermal film anemometer disclosed in the present application is a film of carbon nanotube material whose resistance value changes with temperature. The thermal film anemometer is placed in an airflow, and the heated carbon nanotube film contacts the airflow. The carbon nanotube film loses heat with the flowing airflow, causing its own temperature to change, thereby causing a change in its own resistance. The resistance change signal of the carbon nanotube film can contain information characterizing the wind speed, and by processing the amplified resistance change signal, reference data for calculating the wind speed can be obtained. Among them, the thermal sensitivity of the carbon nanotube film far exceeds that of the metal film, and the thickness of the carbon nanotube film with the same thermal sensitivity is much smaller than that of the metal film, which greatly improves the sensitivity of the thermal film anemometer, and even the resistance change signal caused by the slight heat change of the carbon nanotube film can be captured in time.

[0042] The hot film anemometer disclosed in this embodiment improves the sensitivity of the hot film anemometer by improving the hot film in the detection element. The staff can obtain more accurate reference data for calculating the wind speed based on the processing results of the amplified signal.

[0043] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A hot film anemometer, characterized in that: include: Detection elements, signal converters and signal processors; The detection element comprises at least one group of carbon nanotube films, wherein the carbon nanotube films are thin films of carbon nanotube materials whose resistance value changes with temperature; The detection element is used to output a resistance change signal of the carbon nanotube film, the output end of the detection element is connected to the input end of the signal converter, and the signal converter is used to amplify the resistance change signal to obtain an amplified signal; The output end of the signal converter is connected to the input end of the signal processor, and the signal processor is used to process the amplified signal output by the signal converter.

2. The hot film anemometer according to claim 1, characterized in that: The detection element at least further comprises: a support structure for fixing the edge of the carbon nanotube film and laying the carbon nanotube film flat.

3. The hot film anemometer according to claim 2, characterized in that: The support structure at least comprises: a base and a top cover, and at least two support rods are fixedly connected to the edge of the base, and the support rods are used to support the top cover; Wherein, two sides of the carbon nanotube film are respectively fixed to the two support rods.

4. The hot film anemometer according to claim 1, characterized in that: Also includes: A display connected to the output end of the signal processor is used to display the processing result of the signal processor on the amplified signal.

5. The hot film anemometer according to claim 1, characterized in that: Also includes: The communication module connected to the output end of the signal processor is used to send the processing result of the signal processor on the amplified signal to the user end.

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