JPH03296629A - Temperature or pressure sensor with float or balloon - Google Patents

Abstract

PURPOSE:To enable remote measurement of a temperature or a pressure in a liquid by attaching a float or balloon to a sensor. CONSTITUTION:A sensor 22 for measuring temperature is integrated with a float 23 and the float 23, for example, has a required coating of an acid- resisting, solvent-resisting agent or the like applied on the outer circumference of a foamed resin 24. With such an arrangement, the sensor 22 floats near the surface of various liquids and can measure temperatures at points near the liquid surface. The balloon 34 is filled with a lighter gas according to a density of a gas to be measured as compared therewith. For example, when the gas to be measured in temperature is air, He is filled or when it is a gas heavier than air, for example, chlorine gas, air is done. Moreover, a ferromagnetic body or a magnet 26 is provided at a proper point of the balloon 34 and a position of the sensor 22 is controlled with the magnet 26 from outside a container filled with the gas.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention uses a float or balloon attached to wirelessly measure the temperature or pressure of each part of a fluid sealed in a predetermined container or flowing in a pipe. Temperature or pressure sensor JIC
related.

(Prior art) Conventional techniques for measuring temperature or pressure wirelessly
For example, a sensor consisting of a piezoelectric vibrator with an antenna coil attached is placed at the area where the temperature is to be measured, and a radio wave signal of an appropriate frequency is irradiated from the outside to forcibly excite the piezoelectric vibrator. When the irradiation is stopped, the piezoelectric vibrator subjected to forced trap excitation continues to vibrate for a while at a resonant frequency corresponding to the temperature trap around it. There is a system to know the temperature of

Furthermore, a system in which the transmission and reception of signals is replaced with ultrasonic waves has been proposed by the present inventors, and according to this system, the vibrating piece used in the sensor does not necessarily have to be a piezoelectric material, and therefore an electrode such as that attached to a piezoelectric material can be used. Since the antenna coil is also unstable, it is possible to make the sensor ultra-small and low-cost.

Moreover, when signals are transmitted and received using radio waves, wireless sensing through metal walls is completely impossible, whereas ultrasonic waves have the advantage of being able to propagate through any solid wall.

Therefore, this type of sensor is conventionally fixed at a specific position in a living body, container, or tube for the purpose of measuring temperature at a certain point in the living body, or measuring temperature or pressure at a predetermined position in a container or tube. The temperature at various locations in the fluid inside the container or pipe, especially at the desired location,
No means of measuring pressure wirelessly has been considered.

(Object of the Invention) As described above, the present invention wirelessly measures the temperature or pressure of each part of the container or pipe of the fluid filled or flowing inside the container or pipe, and the measurement point can be arbitrarily set from outside the container or pipe. The purpose is to provide a sensor that can be controlled.

(Summary of the Invention) In order to achieve the above-mentioned objects, the sensor according to the present invention is equipped with a float or a balloon, and a part thereof is made of a ferromagnetic material or a magnet. Alternatively, the position of the sensor may be controlled using a grinding stone from outside the tube.

(Examples) The present invention will be described in detail below based on the embodiments shown in the drawings.

Prior to describing embodiments, an overview of a wireless sensing system to which the present invention is applied will be briefly explained in order to facilitate understanding of the present invention.

FIG. 5 is a diagram showing the concept of a wireless temperature sensor that uses electromagnetic waves as a medium for signal reception, which has been studied in the past.
At the same time, the electrode terminals of the piezoelectric vibrator 2 are directly connected to the antenna fill 4, and the outer periphery of the antenna coil 4 is covered with a plastic cap 5.

10,000, the measurement system connects the oscillator 8 and receiver 9 via the antenna coil 6Ktffi wave transmitter/receiver switch 7, and the receiver 9
The frequency of the signal received is read by a frequency counter 10. hill.

Reference numeral 11 denotes a system controller, which controls the above-mentioned switch 79, oscillator 8, and receiver 9 at appropriate timings to be described later.

The fixed system of the wireless temperature 11 having the above-mentioned configuration is based on the timing chart. As shown in FIG. After forced excitation, the irradiation of the electromagnetic waves is stopped. During this time, the piezoelectric vibrator 2 vibrates at a resonant frequency corresponding to the surrounding temperature, and the antenna coil 4 of the sensor 1 emits electromagnetic waves based on the reverberant vibrations, which are then transmitted to the antenna coil 6 of the measurement system. Received.

If the frequency is read by the frequency counter 10 via the receiver 9, the temperature around the sensor 1 can be known.

The system shown in FIG. 6 replaces radio waves with ultrasonic waves as the signal reception medium of the temperature measurement system described above, and the sensor 12
For example, an electrodeless piezoelectric vibrator or a single vibrating piece 13
is sealed in a capsule 14. - For the measurement system, it is sufficient to replace the antenna filter 6 with an ultrasonic microphone 15, and its operating principle is exactly the same as that in which radio waves are used as a signal reception medium.
Alternatively, it is suitable for temperature measurement through metal walls etc. that do not transmit radio waves.

Furthermore, FIG. 7 (al is a sectional view showing an example of a sensor for measuring pressure, in which the front and back sides of the piezoelectric vibrator 16 are sealed with a diagram 17, and the electrode leads 1 on the front and back sides of the vibrator 16 are sealed.
8' to the antenna φ coil 4, respectively, and the antenna coil 4 may be handled with a plastic cap 5. By doing so, the diagram 17 expands and contracts due to fluctuations in the surrounding pressure VC, which causes the piezoelectric vibrator 16 to expand and contract.
The pressure can be read from the fluctuations in the resonance frequency.

In the same figure (b+ is a partially cutaway perspective view showing -fl' of the ultrasonic pressure sensor, a double tuning fork type vibrating piece 19 is attached to a metal case between bases 20 and 20 having an oval cross section with both ends fixed. 21. By doing so, when the case 21 is deformed by the pressure around it, the twin tuning fork type vibrating piece 19 expands and contracts in the longitudinal direction, and the resonant frequency accordingly increases. It changes.

When trying to measure, for example, the temperature or pressure of a liquid or gas in a container or pipe using a measurement system such as the one described above, conventionally the sensor was left on the bottom of the container or the wall of the pipe, or it was fixed to a machine. As mentioned above, it was difficult to freely select the temperature measurement site because it was common and rare.

In order to solve this problem, the sensor according to the present invention basically has a configuration as shown in FIGS. 1(a) to 1(d).

That is, in FIG. 1 (al), a temperature measurement sensor 22 is integrated with a float 23, and the float 23Fi is, for example, a foamed resin 24 whose outer periphery is coated with a required coating 25 such as acid-resistant and solvent-resistant. With such a configuration, the sensor 22 can float near the surface of various liquids, making it possible to measure the temperature at various locations near the liquid surface.

However, with a sensor configured as described above, F
i It is difficult to measure the temperature of any part of the liquid. Therefore, as shown in FIG. 2B, a block of ferromagnetic material 9 such as ferrite, iron, nickel, etc. or a permanent magnet piece 26 is buried in the float 23, and the sensor 22 is fixed thereto. In this way, it becomes possible to freely control the position of the sensor using a magnet from the outer wall surface of the container or tube filled with liquid.

Of course, in this case, it goes without saying that the container tube must be made of a non-magnetic material or a weakly magnetic material.

Furthermore, if the preliminary buoyancy of the entire sensor is brought close to zero by appropriately adjusting the volume of the material of the float and/or the weight of the buried ferromagnetic block 26, etc. Alternatively, a magnet moving along the outer wall of the tube could easily measure the temperature at any depth in the liquid.

The same figure (C) shows a hollow float formed with a rubber magnet 27 and a required coating 28 applied to its surface.
di indicates an embodiment in which ferromagnetic pieces or magnet pieces 29 are dispersed in the foamed resin 24.

These are only examples, and it is obvious that various embodiments can be made as long as they do not go against the basic spirit of the present invention, and it goes without saying that these are also part of the present invention. do not have.

By the way, in all of the above-mentioned embodiments except for the one shown in FIG. 1(a), the position control magnet is drawn near the inner wall of the container or tube filled with liquid, so the temperature only near that part is However, when it comes to measuring temperature, there is a slight lack of freedom in selecting the temperature on the outer side.

In order to solve this problem, Figure 2 (a) and (b) K
As shown, a two-stage arm 32ft equipped with a slider 31 or wheels (not shown) capable of sliding along the inner wall 3° of the container or tube shown in phantom lines, and a float fixed to each other at a required interval. If a ferromagnetic material piece or a magnet piece 26 is fixed near the slider 31 or the wheel, such float ti can be reduced. Since it can be moved freely inside a tube or container that is at least straight or has a curvature above a certain level by means of a magnet 33 that moves on the outer wall of the container or tube, it is possible to measure the temperature of any location in the liquid. It will be possible.

Similarly, if the arm 32 is configured to be divided and slidable, the float as described above will be able to accommodate a container or pipe that is directly connected to the outside. Regarding the position of the sensor on the arm 32, it would be convenient to provide a sensor attachment that can slide on the arm 32, allowing the sensor to be placed at any position in the radial direction of the container or tube.

Although the sensor for measuring the temperature of liquid has been described above, the basic idea of the present invention can be similarly applied to measuring the temperature of gas.

That is, as shown in FIG.
FIG. 3 is a sectional view showing an example in which the balloon 34 is fixed.
The inside is filled with a lighter gas depending on the density of the gas to be measured. For example, if the gas whose temperature is to be measured is air, it may be filled with He, and if the gas is heavier than air, such as chlorine scum, it may be filled with air.

It is also obvious that the material of the balloon should be selected depending on the properties and temperature of the waste to be measured, and that an appropriate coating should be applied to the outer periphery of the balloon.

Furthermore, it is preferable to attach a ferromagnetic material or a magnet 26 to a suitable position on the balloon 34 so that the position of the sensor 22 is controlled by the magnet from outside the gas-filled container or tube.

In FIG. 3B, the balloon 35 is shaped like a disk and has a large number of cells 22 on its outer periphery.

By doing so, it becomes possible to measure the temperature at several locations at the same time.

At this time, if the attitude of the balloon 35 is controlled by appropriately moving a magnet outside the container or tube filled with the waste to be measured, the temperature measurement position can be selected relatively freely.

In addition, when trying to measure the distribution of temperature within the container or cylinder 30 filled with gas at different altitudes, KFi Fig. 4 (at and (b)
), for example, a banana-shaped balloon 36 is attached to the tip of a suitable arm 37, and a ferromagnetic material or magnet plate 38 is attached as a slider to the contact surface of the balloon 36 with the inner wall of the container or tube 30. The sensor 22 may be fixed at a proper position on the arm 37, and the position of the sensor 22 attached to the balloon 36 and the arm 37 extending therefrom may be controlled using a magnet from outside the container or cylinder 30.

Above, we have explained the method of measuring the temperature and pressure of the core by moving a temperature or pressure sensor attached to a float or balloon to an arbitrary position within a container, tube, or cylinder filled with fluid using a magnet. .

The magnet that moves along the outer wall of the container or the like when controlling the position of the sensor attached to the float or balloon may be a permanent magnet or an electromagnet.

Furthermore, the number of control magnets is not necessarily limited to one; for example, if a plurality of electromagnets are fixed at a predetermined position and their magnetic forces are controlled appropriately, the position and attitude of the float or balloon can be changed. You can do it like this.

(Effects of the Invention) Since the present invention is constructed as described above, it is suitable for measuring the temperature or pressure of a fluid flowing near a liquid surface or inside a pipe, and is suitable for measuring the temperature or pressure within a fluid by using a magnet. Alternatively, if a sensor that can control the pressure measurement site is used, the temperature distribution of the fluid can be measured wirelessly from the outside of a container, pipe, etc. filled with the fluid, so temperature correction and chemical reactions can be easily performed when precisely measuring fluid density. It is extremely effective in measuring the temperature and pressure distribution inside a cylinder, and in measuring the temperature and pressure management of explosive fluids.

[Brief explanation of the drawing]

FIGS. 1(al to d) are cross-sectional views showing different embodiments of the float-equipped sensor according to the present invention, and FIG.
al and (bl are respectively a plan view and a side view showing other embodiments of the sensor with a float according to the present invention, and FIGS. 3(a) and (b) respectively are different implementations of the sensor with a balloon according to the present invention. FIGS. 4A and 4B are plan views and side views showing other embodiments of the balloon-equipped sensor according to the present invention, and FIGS. 5 and 6 are cross-sectional views showing examples of the present invention. A conceptual diagram illustrating a measurement system for a wireless temperature sensor that uses electromagnetic waves and ultrasonic signals as a reception medium,
Figure 7 (al and (bl) are a sectional view and a partially cutaway perspective view showing different configurations of the pressure sensor used in the present invention, respectively. 1.12 and 22...・Sensor,
2.13°16 and 19... Vibration piece,
23...--Float, 34.
35 and 36...Nokuroof,
26, 27. 29 and 38... Ferromagnetic material or magnet, 30... Container or tube.

Claims (2)

[Claims] (1) After the vibrating piece is forcibly excited by externally irradiated radio waves or ultrasonic waves and starts vibrating at a resonant frequency corresponding to its surrounding temperature or pressure, the externally irradiated radio waves or ultrasonic waves In a type of sensor that measures the temperature or pressure around the vibrating piece by detecting the frequency of reverberant radio waves or ultrasonic waves emitted from the vibrating piece when the irradiation of sound waves is stopped, the sensor is equipped with a float or A temperature or pressure sensor equipped with a float or a balloon, characterized in that the temperature or pressure in a fluid can be remotely measured by attaching the balloon. (2) Part or all of the float, balloon, or sensor itself is made of a ferromagnetic material or magnet, and the sensor is suspended in the fluid, and the position of the sensor is located in a container filled with the fluid or through which the fluid flows. The temperature or pressure sensor equipped with a float or balloon according to claim 1, wherein the temperature or pressure sensor is capable of being controlled by a magnet (including an electromagnet) from outside the tube.