JP2017122626A - Measuring apparatus and manufacturing method of measuring apparatus - Google Patents

Abstract

An object of the present invention is to provide a measuring device that can maintain the strength of a tubular member and accurately measure the flow rate of a fluid, and that can be manufactured at low cost. A measuring device according to one aspect of the present invention includes a tubular member whose inner circumferential surface has a second axis eccentrically parallel to the outer circumferential surface's first axis, and which is fixed on the outer circumferential surface of the tubular member. In the cross section of the tubular member, the length from the part where the sensor contacts the tubular member to the second axis is shorter than the length to the first axis. [Selection diagram] Figure 1

Description

  The present invention relates to a measuring apparatus and a method for manufacturing the measuring apparatus.

  Conventionally, a flow sensor for liquid described in Patent Document 1 has been known as a flow sensor for detecting a change in the flow rate of a fluid. The flow sensor has a semiconductor module in which two temperature sensors and a heat source provided on each of the upstream side and the downstream side of the fluid flow are incorporated. The flow sensor includes a pipe (pipe) for guiding a liquid, the semiconductor module (sensor) is provided on the outer surface of the pipe via an adhesive such as a heat conductive paste, and two temperature sensors and a heat source are provided on the outer surface of the pipe. (FIGS. 1 to 3 of Patent Document 1). Such a flow sensor structure is employed when it is not desired to contact the fluid with a material other than the pipe, or when the semiconductor module is larger than the inner diameter of the pipe and the semiconductor module cannot be disposed inside the pipe. .

Special table 2003-532099 gazette

  In the flow sensor of Patent Document 1, the semiconductor module is bonded to the outer wall of the pipe. Here, the thickness of the pipe, which is the distance between the outer peripheral surface and the inner peripheral surface of the pipe, greatly affects the sensor sensitivity. In general, the sensor sensitivity decreases as the pipe thickness increases, and the flow rate of the fluid may not be measured.

  In order to prevent a decrease in the sensitivity of the sensor as described above, it is conceivable to reduce the thickness of the pipe by grinding the outer peripheral surface of the pipe on which the semiconductor module is arranged. However, this thin processing is costly.

  Further, when the thickness of the pipe at the position where the semiconductor module is disposed is mechanically processed, the processed surface of the pipe is damaged, so that the strength of the pipe is lowered and sensor characteristics may be affected. Thus, it is not easy to manufacture a flow sensor that can accurately measure the fluid flow rate by mechanically adjusting the thickness of the pipe. Similar problems may occur in measurement devices other than a flow sensor in which a sensor is fixed to a pipe.

  Therefore, an object of the present invention is to provide a measuring device that can maintain the strength of the tubular member and can accurately measure the flow rate of the fluid and can be manufactured at low cost.

  In order to solve the above problems, a measuring apparatus according to one aspect of the present invention includes a tubular member in which a second axis of an inner peripheral surface is eccentric in parallel with a first axis of an outer peripheral surface, and an outer periphery of the tubular member A sensor fixed on the surface, and in a cross section of the tubular member, a length from a portion where the sensor contacts the tubular member to the second axis is shorter than a length to the first axis.

  In the measurement apparatus, the sensor may be fixed to a portion where the thickness of the tubular member in the cross-sectional direction is the thinnest.

  In the measurement apparatus, the sensor includes a first intersection where a straight line extending from the second axis toward the outer peripheral surface and the inner peripheral surface intersects the inner peripheral surface and a second intersection where the straight line intersects the outer peripheral surface in the cross section of the tubular member. May be fixed at the second intersection when the distance to is the shortest.

  In the measurement apparatus, the tubular member may be a glass capillary.

  In the measurement apparatus, the sensor may measure the flow velocity of the fluid flowing through the inside of the tubular member.

  In the measurement apparatus, the sensor may measure the flow rate of the fluid flowing through the inside of the tubular member.

  In order to solve the above-described problem, a method for manufacturing a measuring device according to one aspect of the present invention is provided on an outer surface of a tubular member in which a second axis of an inner peripheral surface is eccentric in parallel to a first axis of an outer peripheral surface. The length from the portion where the sensor contacts the tubular member to the second axis is shorter than the length to the first axis in the cross section of the tubular member.

  In the method for manufacturing the measuring apparatus, the method further includes a step of manufacturing a tubular member, and the step of manufacturing the tubular member is performed by stretching a base material in which the axis of the inner peripheral surface is eccentric in parallel with the axis of the outer peripheral surface. Thus, a tubular member may be manufactured.

  In the method for manufacturing the measuring apparatus, the sensor may be fixed to a portion where the thickness in the cross-sectional direction of the tubular member is the thinnest.

  In the method for manufacturing the measuring apparatus, the sensor includes a first intersection where the straight line extending from the second axis toward the outer peripheral surface and the inner peripheral surface intersects the inner peripheral surface and the straight line intersects the outer peripheral surface in the cross section of the tubular member. You may fix to the 2nd intersection in case the distance with a 2nd intersection is the shortest.

  In the method for manufacturing the measuring apparatus, the tubular member may be a glass capillary.

  In the method for manufacturing the measuring device, the sensor may measure the flow velocity of the fluid flowing inside the tubular member.

  In the method for manufacturing the measuring device, the sensor may measure the flow rate of the fluid flowing through the inside of the tubular member.

  ADVANTAGE OF THE INVENTION According to this invention, it is a measuring device which can maintain the intensity | strength of a tubular member and can measure the flow volume of a fluid correctly, Comprising: The measuring device which can be manufactured at low cost can be provided.

It is a schematic sectional drawing which shows the structural example of the flowmeter which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the structural example of the flowmeter which concerns on embodiment of this invention. It is a perspective view which shows the structural example of the flow sensor which concerns on embodiment of this invention. It is sectional drawing seen from the IV-IV direction of FIG. 3 of the flow sensor which concerns on embodiment of this invention. It is an enlarged view of a schematic sectional view showing a configuration example of a flow meter according to an embodiment of the present invention. It is sectional drawing which showed the manufacturing process of the flowmeter which concerns on embodiment of this invention. It is sectional drawing which showed the manufacturing process of the flowmeter which concerns on embodiment of this invention. It is sectional drawing which showed the manufacturing process of the flowmeter which concerns on embodiment of this invention. It is an enlarged view of a schematic sectional view showing a configuration example of a flow meter according to an embodiment of the present invention. It is an enlarged view of a schematic sectional view showing a configuration example of a flow meter according to an embodiment of the present invention. It is an enlarged view of a schematic sectional view showing a configuration example of a flow meter according to an embodiment of the present invention. It is a bottom view which shows the structural example of the flowmeter which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. The drawings are schematic and do not necessarily match actual dimensions and ratios. In some cases, the dimensional relationships and ratios may be different between the drawings.

(Constitution)
A flow meter which is an example of a measuring apparatus according to an embodiment of the present invention shown in FIGS. 1 and 2 is a sensor that measures the flow rate of a fluid flowing in the pipe 11 and attached to the outer wall of the pipe 11 and the pipe 11. A certain flow sensor 51. 1 and 2 are cross-sectional views when the flow meter is cut in a direction perpendicular to the extending direction of the pipe 11.

  The pipe 11 (tubular member) is a tubular member that allows fluid to pass through, and the axis S2 (second axis) of the inner peripheral surface IP is parallel to the axis S1 (first axis) of the outer peripheral surface OP. It is configured to be eccentric. The pipe 11 has, for example, an appropriate inner diameter corresponding to the flow rate of the fluid, a wall thickness that can withstand the pressure of the fluid, and an optimum length, which are determined according to use conditions. The outer diameter of the pipe 11 is, for example, several mm. The pipe 11 is made of, for example, a material such as glass, and may be made of, for example, a glass capillary.

  The flow sensor 51 (sensor) is a measuring means for measuring at least one of the flow velocity and the flow rate of the fluid flowing through the pipe 11. The flow sensor 51 is fixed on the outer peripheral surface of the pipe 11. For example, in the cross section of the pipe 11, the length dy from the portion P where the flow sensor 51 contacts the pipe 11 to the axis S2 (second axis) of the inner peripheral surface IP is the axis S1 (first) of the outer peripheral surface OP. The flow sensor 51 is fixed on the outer peripheral surface of the pipe 11 so as to be shorter than the length dx up to one axis). FIG. 1 illustrates an example in which the flow sensor 51 is fixed to a portion where the cross-sectional thickness of the pipe 11 is the thinnest. However, the flow sensor 51 does not necessarily have the cross-sectional thickness of the pipe 11 being the largest. The flow sensor 51 need only be fixed on the outer peripheral surface of the pipe 11 such that the length dy is shorter than the length dx, as shown in FIG.

  The flow sensor 51 includes a substrate 101 provided with a cavity 102 and an insulating film 103 that covers the substrate 101. The insulating film 103 includes a sensor unit 100 and an electrical connection unit 109, and a portion covering the cavity 102 forms a heat insulating diaphragm. The flow sensor 51 is manufactured by, for example, backside etching that forms the cavity 102 from below the substrate 101. A specific configuration of the flow sensor 51 will be described with reference to FIGS. 3 and 4.

  FIG. 3 is a perspective view illustrating a configuration example of the flow sensor according to the embodiment of the present invention. 4 is a cross-sectional view of the flow sensor according to the embodiment of the present invention as seen from the IV-IV direction of FIG. As shown in FIGS. 3 and 4, the flow sensor 51 includes, for example, a substrate 101 provided with a cavity 102 (FIG. 4), and an insulating film 103 disposed on the substrate 101 so as to cover the cavity 102. The sensor unit 100 provided on the insulating film 103, the ambient temperature sensor 107, and the electrical connection unit 109 that outputs an electrical signal corresponding to the physical quantity detected by the sensor unit 100 are configured.

  The sensor unit 100 is, for example, temperature detection means configured to include a heater 104 provided on the insulating film 103 and temperature measuring resistance elements 105 and 106. For example, the sensor unit 100 is disposed on the insulating film 103 of the flow sensor 51, and the sensor unit 100 may be configured to protrude upward from the insulating film 103, or may be embedded in the insulating film 103. It may be configured. The sensor unit 100 may include an ambient temperature sensor 107 described later in addition to the heater 104 and the resistance temperature detectors 105 and 106.

  The ambient temperature sensor 107 measures the temperature of the fluid flowing through the pipe 11. The heater 104 is disposed substantially at the center of the insulating film 103 that covers the cavity 102, and heats the fluid flowing through the pipe 11 so that the temperature is higher than the temperature measured by the ambient temperature sensor 107.

As a material of the substrate 101, for example, silicon (Si), glass, ceramic, or the like can be used. Substrate 101 may, for example, may be configured as a FPC (F lexible p rinted c ircuits ). As a material of the insulating film 103, silicon oxide (SiO ₂ ), silicon nitride (SiN), or the like can be used. Further, platinum (Pt) or the like can be used as the material of each of the heater 104, the resistance temperature detector 105, the resistance temperature detector 106, and the ambient temperature sensor 107.

  The electrical connection unit 109 is connected to various resistance elements including the heater 104, the resistance temperature sensor element 105, and the resistance temperature sensor element 106, and is a means for outputting information on the electrical resistance of each resistance element. For example, as shown in FIG. 2, the electrical connection portion 109 is disposed in the vicinity of a corner portion having a diagonal relationship with the substrate 101, and is connected to the electrical resistances of the heater 104, the resistance temperature detector 105, and the resistance temperature detector 106. A corresponding electrical signal is taken out via a wire or the like (not shown) and output to a flow rate measuring unit (not shown). For example, the electrical connection unit 109 is disposed on the insulating film 103, and the sensor unit 100 may be configured to protrude upward from the insulating film 103 or may be configured to be embedded in the insulating film 103. Also good.

  FIG. 5 is an enlarged view of a schematic cross-sectional view showing a configuration example of the flow meter according to the embodiment of the present invention. In particular, FIG. 5 is a cross-sectional view as seen from the IV-IV direction of FIG. 2 in a flow meter configured by fixing piping along the center line C of the flow sensor 51 of FIG. That is, FIG. 5 is a cross-sectional view when a flow meter including a pipe and a flow sensor attached to the outer peripheral surface of the pipe is cut along the axis of the pipe. FIG. 5 is an enlarged schematic sectional view of a portion where the pipe and the flow sensor are fixed.

  As shown in FIG. 5, when the sensor unit 100 of the flow sensor 51 is thermally connected to the pipe 11, the heat of the heater 104 of the sensor unit 100 propagates to the fluid in the pipe 11 as indicated by an arrow A <b> 1. To do. Next, the heat of the fluid changed by the heat propagated from the heater 104 propagates in the direction toward the temperature measuring resistance element 105 indicated by the arrow A2 and in the direction indicated by the arrow A3. The heat propagation in the direction of the arrow A1 and the heat propagation in the directions of the arrows A2, 3 are combined to transfer heat in both directions. When the fluid in the pipe 11 is flowing from the upstream side to the downstream side, the heat applied by the heater 104 is conveyed in the downstream direction (transport effect). Accordingly, the temperature of the resistance temperature detector 106 becomes higher than the temperature of the resistance temperature detector 105, and a difference occurs between the electrical resistance of the resistance temperature detector 105 and the electrical resistance of the resistance temperature detector 106. This difference in electrical resistance is known to correlate with the speed and flow rate of the fluid flowing through the pipe 11. For this reason, the speed and flow rate of the fluid flowing through the pipe 11 can be measured (calculated) based on the difference between the electric resistance of the temperature measuring resistance element 105 and the electric resistance of the temperature measuring resistance element 106.

  Here, in the cross section of the pipe 11, the length dy from the portion P where the flow sensor 51 contacts the pipe 11 to the axis S2 (second axis) of the inner peripheral surface IP is the axis S1 ( By fixing the flow sensor 51 on the outer peripheral surface of the pipe 11 so as to be shorter than the length dx to the first axis), heat conduction between the flow sensor 51 and the fluid in the pipe 11 Will be better. Therefore, it is possible to accurately measure the speed and flow rate of the fluid flowing through the pipe 11.

(Manufacturing process)
The manufacturing process of the flowmeter according to the embodiment of the present invention will be described with reference to FIGS. 6 to 8 are cross-sectional views showing the manufacturing process of the flow meter according to the embodiment of the present invention. In particular, FIG. 6 is a diagram showing a pipe base material for manufacturing a pipe. FIG. 7 is a view showing the pipe after the pipe base material is stretched. FIG. 8 is a view showing a flow meter in which a flow sensor is fixed to a pipe. FIG. 9 to FIG. 11 are enlarged views of sectional views when a flowmeter including a pipe and a flow sensor attached to the outer wall of the pipe is cut in a direction perpendicular to the axis of the pipe.

The flow meter according to the embodiment of the present invention is manufactured through the following steps.
(Process 1)
First, as shown in FIG. 6, a perforated pipe base material 10 (base material) is formed in which the axial center Sm of the inner peripheral surface IPm is eccentric in parallel to the axial center Sn of the outer peripheral surface OPn. The outer diameter of the pipe base material 10 is, for example, 50 mm. The piping base material 10 is made of a material such as glass, for example, similarly to the piping.

  In Step 1, by supplying the pipe base material 10 in which the axial center Sm of the inner peripheral surface IPm is eccentric in parallel to the axial center Sn of the outer peripheral surface OPn in advance, Step 1 is omitted, and Step 2 and subsequent steps. May be implemented.

(Process 2)
As shown in FIG. 7, a pipe 11 (tubular member) is manufactured in which the axis S2 (second axis) of the inner peripheral surface IP is eccentric in parallel to the axis S1 (first axis) of the outer peripheral surface OP. To do. For example, the pipe 11 is manufactured by stretching a pipe base material 10 in which the axis Sm of the inner peripheral surface IP is eccentric in parallel with the axis Sn of the outer peripheral face OP shown in FIG.

  Specifically, in the electric furnace, after the pipe base material 10 is softened at a temperature several hundred degrees Celsius higher than the softening point (for example, several thousand degrees Celsius) of the pipe base material 10, the softened pipe base material 10 is stretched. By doing so, the pipe 11 having an outer diameter of, for example, several mm is manufactured. In addition, in order to obtain the pipe 11 having a desired outer diameter and length in the drawing direction from the pipe base material 10, it can be uniformly drawn using an optimum drawing temperature and drawing speed.

(Process 3)
As shown in FIG. 8, the flow sensor 51 (sensor) is fixed on the outer peripheral surface OP of the pipe 11.

  As described above, the flow sensor 51 is fixed to the portion where the thickness in the cross-sectional direction of the pipe 11 is the thinnest. For example, as shown in FIG. 9, the flow sensor 51 is a pipe perpendicular to the axis S1 (first axis) of the outer peripheral surface of the pipe 11 and the axis S2 (second axis) of the inner peripheral surface. 11, a straight line L1 extending from the axis S2 toward the outer peripheral surface OP and the inner peripheral surface IP of the pipe 11 intersects the inner peripheral surface IP (first intersection) and the straight line L1 is the outer peripheral surface OP. It is fixed at P2 (second intersection) when the distance to the intersecting intersection P2 (second intersection) is the shortest.

  On the other hand, as a comparative example, as shown in FIG. 10, the flow sensor 51 is fixed to a portion where the cross-sectional thickness of the pipe 11 is the thickest. For example, as shown in FIG. 10, the flow sensor 51 is a pipe perpendicular to the axis S1 (first axis) of the outer peripheral surface of the pipe 11 and the axis S2 (second axis) of the inner peripheral surface. 11, a straight line L1 extending from the axis S2 toward the outer peripheral surface OP and the inner peripheral surface IP of the pipe 11 intersects the inner peripheral surface IP and an intersection P2 where the straight line L1 intersects the outer peripheral surface OP. When the distance is fixed to P4 when the distance is the longest, the thickness in the cross-sectional direction of the pipe 11 at P4 where the flow sensor 51 is fixed becomes thick. There is a possibility that the heat flow becomes poor and the flow rate of the fluid cannot be measured accurately. Therefore, as shown in FIG. 9, the flow sensor 51 is preferably fixed at the intersection P2.

  In addition, the thickness of the piping 11 which is the distance between the outer peripheral surface OP and the inner peripheral surface IP of the piping 11 is configured to be thin (for example, several tens of μm) so as not to hinder heat conduction.

  The method of fixing the flow sensor 51 to the outer peripheral surface of the pipe 11 includes at least the following method.

  For example, there is a method in which the flow sensor 51 is manufactured separately, and the manufactured flow sensor 51 is installed and fixed on the outer peripheral surface of the pipe 11. Specifically, a heat conductive adhesive (not shown) is attached so as to cover at least the sensor unit 100 disposed on the substrate 101 of the flow sensor 51, and the heat conductive adhesive is used on the substrate 101. The arranged sensor unit 100 is installed on the outer peripheral surface of the pipe 11 and the thermally conductive adhesive is cured.

  In addition, you may adhere a heat conductive adhesive so that only the surface of the sensor part 100 may be covered. In addition, in order to more firmly fix the flow sensor 51 and the pipe 11, a heat conductive adhesive is attached so as to cover only the surface of the sensor unit 100, and then leaks onto the insulating film 103 on the substrate 101. A thermally conductive adhesive may be further attached. Furthermore, the heat conductive adhesive does not necessarily need to cover all of the sensor unit 100, and heat transferred from the flow sensor 51 to the fluid through the wall of the pipe 11 and flows from the fluid through the wall of the pipe 11. What is necessary is just to cover the sensor part 100 to such an extent that the heat transmitted to the sensor 51 can be efficiently transmitted.

  There is no restriction | limiting in particular in the method of hardening a heat conductive adhesive. For example, methods for curing a heat conductive adhesive include a curing method by light irradiation and a curing method by heating, but are not limited thereto. For example, when the heat conductive adhesive is naturally cured, the heat conductive adhesive may be cured by being left for a predetermined period after being attached. In addition, when the adhesive force of a heat conductive adhesive is low, you may use some attachments (not shown) for fixing the flow sensor 51 firmly with the piping 11, for example.

  In addition, a heat conductive adhesive contains the paste containing metal particles, such as silver, copper, gold | metal | money, aluminum, for example. The paste includes, for example, a material obtained by mixing a conductive filler and a binder resin. Examples of the conductive filler include fine metal powders such as silver, copper, iron, and nickel, ceramic particles, and carbon black. The binder resin includes resins such as an epoxy resin, a polyester resin, a urethane resin, a phenol resin, and an imide resin.

  Another method includes a method of directly forming and fixing the constituent elements of the flow sensor 51 by performing a predetermined patterning method on the outer peripheral surface of the pipe 11.

FIG. 11 is an enlarged view of a schematic cross-sectional view showing a configuration example of the flow meter according to the embodiment of the present invention. FIG. 12 is a bottom view showing a configuration example of the flow meter according to the embodiment of the present invention. As shown in FIGS. 11 and 12, the sensor unit 100, the ambient temperature sensor 107, and the electrical connection unit 109 made of platinum (Pt) or the like are formed by, for example, a thin film formation method such as vapor deposition or sputtering, or lithography / nano It is formed on the outer peripheral surface of the pipe 11 using a patterning method or the like. Further, in order to protect the surfaces of the sensor unit 100 and the ambient temperature sensor 109, a protective film 110 containing silicon nitride (SiN), silicon oxide (SiO ₂ ), fluorine-based resin, or the like is formed in the protective film forming region 110R. Also good. Each of the sensor unit 100 and the ambient temperature sensor 109 is connected to each electrical connection unit 109 using a wire or the like.

  According to this embodiment, in the cross section of the pipe 11, the flow sensor 51 has a length dy from the portion P where the flow sensor 51 contacts the pipe 11 to the axis S <b> 2 (second axis) of the inner peripheral surface IP. The outer circumferential surface OP is fixed on the outer circumferential surface of the pipe 11 so as to be shorter than the length dx to the axis S1 (first axial center) of the outer circumferential surface OP. Therefore, heat conduction between the flow sensor 51 and the fluid in the pipe 11 is improved. Therefore, it is possible to accurately measure the speed and flow rate of the fluid flowing through the pipe 11. Since heat conduction between the flow sensor 51 and the fluid in the pipe 11 is improved, it is not necessary to thin the outer peripheral surface of the pipe 11 by grinding or the like. Accordingly, there is no reduction in strength due to damage to the processed surface, and manufacturing can be performed at low cost.

(Other embodiments)
Each above-mentioned embodiment is for making an understanding of the present invention easy, and does not limit and interpret the present invention. Moreover, the above-described embodiment is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described above. That is, the present invention can be implemented with various modifications (combining the embodiments) without departing from the spirit of the present invention.

  In each of the above-described embodiments, the flow meter is used as the measurement device and the flow sensor is used as the sensor.However, the measurement device is not limited thereto, and any measurement device may be used as long as the sensor is installed on the outer wall of the pipe. For example, a calorimeter may be used as the measuring device, a calorimeter sensor may be used as the sensor, a thermometer may be used as the measuring device, and a temperature sensor may be used as the sensor.

DESCRIPTION OF SYMBOLS 1 Flowmeter 10 Piping base material 11 Piping 51 Flow sensor 100 Sensor part 101 Board | substrate 102 Cavity 103 Insulating film 104 Heater 105,106 Temperature measuring resistance element 107 Ambient temperature sensor 109 Electrical connection part

Claims (13)

A tubular member in which the second axis of the inner peripheral surface is eccentric in parallel to the first axis of the outer peripheral surface;
A sensor fixed on the outer peripheral surface of the tubular member;
With
In the cross section of the tubular member, the length from the portion where the sensor contacts the tubular member to the second axis is shorter than the length to the first axis.
measuring device.   The measuring device according to claim 1, wherein the sensor is fixed to a portion where the thickness in the cross-sectional direction of the tubular member is the thinnest. The sensor is
A first intersection where a straight line extending from the second axis toward the outer peripheral surface and the inner peripheral surface intersects the inner peripheral surface and a second intersection where the straight line intersects the outer peripheral surface in the cross section of the tubular member; Fixed to the second intersection when the distance of
The measuring apparatus according to claim 1 or 2.   The measuring apparatus according to claim 1, wherein the tubular member is a glass capillary.   The measuring device according to any one of claims 1 to 4, wherein the sensor measures a flow velocity of a fluid flowing inside the tubular member.   The measuring device according to claim 1, wherein the sensor measures a flow rate of a fluid flowing inside the tubular member. A step of fixing the sensor on the outer peripheral surface of the tubular member in which the second axial center of the inner peripheral surface is eccentric in parallel with the first axial center of the outer peripheral surface;
In the cross section of the tubular member, the length from the portion where the sensor contacts the tubular member to the second axis is shorter than the length to the first axis.
Manufacturing method of the measuring device. Further comprising manufacturing the tubular member;
The step of producing the tubular member produces the tubular member by stretching a base material in which the axis of the outer peripheral surface and the axis of the inner peripheral surface are eccentric in parallel.
A method for manufacturing the measuring apparatus according to claim 7.   The method for manufacturing a measuring apparatus according to claim 7 or 8, wherein the sensor is fixed to a portion where the cross-sectional thickness of the tubular member is the smallest. The sensor is
A first intersection where a straight line extending from the second axis toward the outer peripheral surface and the inner peripheral surface intersects the inner peripheral surface and a second intersection where the straight line intersects the outer peripheral surface in the cross section of the tubular member; Fixed to the second intersection when the distance of
The manufacturing method of the measuring apparatus of any one of Claim 7 to 9.   The method for manufacturing a measuring apparatus according to claim 7, wherein the tubular member is a glass capillary.   The method for manufacturing a measuring apparatus according to claim 7, wherein the sensor measures a flow velocity of a fluid flowing inside the tubular member.   The manufacturing method of the measuring device according to claim 7, wherein the sensor measures a flow rate of a fluid flowing inside the tubular member.

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