CN209927131U - Clinometer - Google Patents

Clinometer Download PDF

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Publication number
CN209927131U
CN209927131U CN201822057162.5U CN201822057162U CN209927131U CN 209927131 U CN209927131 U CN 209927131U CN 201822057162 U CN201822057162 U CN 201822057162U CN 209927131 U CN209927131 U CN 209927131U
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liquid level
liquid
inclinometer
level sensors
level sensor
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陈昌林
吕欣怀
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Jiangsu Hongkai Sensing Technology Co Ltd
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Jiangsu Hongkai Sensing Technology Co Ltd
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Abstract

The application discloses clinometer includes: at least one liquid level sensor; the main body of each liquid level sensor comprises a liquid area and a gas area, the gas area is positioned above the liquid area, the liquid area in the main body of each liquid level sensor is communicated, and the gas area in the main body of each liquid level sensor is communicated; under the condition that the liquid level sensor comprises a first reflection point and a second reflection point, determining an inclination angle based on the length variation of the resonant cavity of different liquid level sensors and the distance between the axes; in general, two liquid level sensors can be used for making a one-way inclinometer, and more than three liquid level sensors can be used for making a two-way inclinometer.

Description

Clinometer
Technical Field
The application relates to a measurement technology, in particular to an inclinometer for measuring an inclination angle.
Background
The inclinometer has different designs according to different measurement principles, and most of the commonly used inclinometers are based on the principles of a Micro Electro Mechanical System (MEMS), a plug resistor, a static leveling, a Fiber Bragg Grating (FBG), a vibrating wire and the like. However, inclinometers designed based on the above measurement principle have at least the following disadvantages: the structure is complicated, the precision is low, and the manufacturing cost is higher.
SUMMERY OF THE UTILITY MODEL
In order to solve the above technical problem, an embodiment of the present application provides an inclinometer.
The inclinometer that this application embodiment provided includes: at least one liquid level sensor; the main body of each liquid level sensor comprises a liquid area and a gas area, the gas area is positioned above the liquid area, the liquid area in the main body of each liquid level sensor is communicated, and the gas area in the main body of each liquid level sensor is communicated; wherein the content of the first and second substances,
the liquid level sensor comprises a first reflection point and a second reflection point, the position of the first reflection point is fixed, the liquid level of the liquid region or floating objects on the liquid level are used as the second reflection point, and the distance between the first reflection point and the second reflection point is the length of the resonant cavity; when the inclination angle of the inclinometer is changed, the liquid level sensor rotates and moves, the liquid level moves in the main body of the liquid level sensor under the action of gravity, so that the length of a resonant cavity of the liquid level sensor is changed, and the inclination angle is determined based on the change amount of the length of the resonant cavity;
alternatively, the first and second electrodes may be,
the liquid level sensor comprises a positive feedback loop, the positive feedback loop comprises a first reflection point and a second reflection point, the position of the first reflection point is fixed, the liquid level of the liquid area or a floater on the liquid level is used as the second reflection point, and the distance between the first reflection point and the second reflection point is the length of the resonant cavity; or, the positive feedback loop only comprises one reflecting point, and the liquid level of the liquid region or the floating object on the liquid level is taken as the reflecting point; when the inclination angle of the inclinometer is changed, the liquid level sensor rotates and moves, the liquid level moves in the main body of the liquid level sensor under the action of gravity, when the positive feedback loop comprises the first reflection point and the second reflection point, the length of the resonant cavity is changed, and the inclination angle is determined based on the change amount of the length of the resonant cavity; when the positive feedback loop only comprises one reflection point, the circumference of the positive feedback loop is caused to change, and the inclination angle is determined based on the circumference change amount of the positive feedback loop.
In one embodiment of the present application, where the liquid level sensor comprises the first reflection point and the second reflection point:
the first reflection point is fixed at any position in the envelope range of the outer shell and the inner rod of the liquid level sensor; alternatively, the first and second electrodes may be,
and taking the joint of the radio frequency coaxial cable adapter in the liquid level sensor, the shell and the inner rod as the first reflection point.
In one embodiment of the present application, the liquid level sensor comprises a cavity length measuring device comprising: a microwave resonant cavity and a demodulation device; wherein the content of the first and second substances,
the microwave resonant cavity comprises a hollow coaxial cable-Fabry-Perot resonant cavity and a reflection point positioned inside the hollow coaxial cable-Fabry-Perot resonant cavity;
the first end of the hollow coaxial cable-Fabry-Perot resonant cavity is connected to a radio frequency coaxial cable adapter, and the radio frequency coaxial cable adapter is connected to the demodulation device through a coaxial cable; or the first end of the hollow coaxial cable-Fabry-Perot resonant cavity is connected to a circuit board as a demodulation device.
In an embodiment of the application, when the total reflectivity of the reflection point inside the hollow coaxial cable-fabry-perot resonator is greater than or equal to a threshold value, the second end of the hollow coaxial cable-fabry-perot resonator has no energy dissipation system, or a load resistor or a coaxial load for dissipating energy is connected between the outer shell and the inner rod of the second end of the hollow coaxial cable-fabry-perot resonator;
and when the total reflectivity of the reflection point in the hollow coaxial cable-Fabry-Perot resonant cavity is smaller than a threshold value, a load resistor or a coaxial load for energy dissipation is connected between the outer shell and the inner rod of the second end of the hollow coaxial cable-Fabry-Perot resonant cavity.
In one embodiment of the present application, the cavity length measuring device is a reflective cavity length measuring device, or a transmissive cavity length measuring device, or a positive feedback loop cavity length measuring device;
correspondingly, the liquid level sensor is a reflection type liquid level sensor, or a transmission type liquid level sensor, or a positive feedback loop type liquid level sensor; when the liquid level sensor is a transmission type liquid level sensor or a positive feedback loop type liquid level sensor, the liquid level sensor at least has the following modes: loop-free mode, positive feedback loop mode; wherein the content of the first and second substances,
the loop-free mode means that the level sensor is transmissive, not including a positive feedback loop;
the positive feedback loop mode means that the level sensor comprises a positive feedback loop.
In one embodiment of the present application, when the liquid level sensor comprises the positive feedback loop, the positive feedback loop employs a loop having two reflection points, or a loop having one reflection point; wherein the content of the first and second substances,
when the positive feedback loop has two reflection points, the positive feedback loop comprises the first reflection point and the second reflection point, the distance between the first reflection point and the second reflection point is the length of the resonant cavity, and the demodulation device is used for measuring the length of the resonant cavity of the positive feedback loop;
when the positive feedback loop has only one reflection point, the liquid level or the floating object on the liquid level is used as the reflection point, and the demodulation device is used for measuring the perimeter of the positive feedback loop.
In an embodiment of the present application, in the case of no energy dissipation system at the second end of the hollow coaxial cable-fabry-perot resonator, the liquid region in each liquid level sensor body is kept connected, and the gas region in each liquid level sensor body is kept connected, by:
the first end of the hollow coaxial cable-fabry-perot resonator of each level sensor is at the top: the second end of each liquid level sensor is of an open structure, each open structure is communicated with or submerged into a liquid area of the same closed container by using a communicating container, or the second end of each liquid level sensor is of a closed structure, an opening is formed in the shell wall corresponding to the liquid area in each liquid level sensor, and the communicating container is used for communicating or submerged into the liquid area of the same closed container between the openings; openings are formed in the shell wall corresponding to a gas area above the liquid level in each liquid level sensor, and each opening is communicated with each other through a vent pipe or is opened in the gas area of the same closed container;
the first end of the hollow coaxial cable-Fabry-Perot resonant cavity of each liquid level sensor is at the bottom: the second end of each liquid level sensor is of an open structure, each open structure is communicated by a vent pipe, or the second end of each liquid level sensor is of a closed structure, an opening is formed in the shell wall corresponding to a gas area above the liquid level in each liquid level sensor, and each opening is communicated by a vent pipe; openings are formed in the shell wall corresponding to the liquid area inside each liquid level sensor, and communication containers are used for communicating the openings.
In an embodiment of the present application, in a case where a load resistor or a coaxial load for dissipating energy is connected between the outer shell and the inner rod of the second end of the hollow coaxial cable-fabry-perot resonator, the liquid region in each liquid level sensor body is kept connected, and the gas region in each liquid level sensor body is kept connected, by:
the first end of the hollow coaxial cable-fabry-perot resonator of each level sensor is at the top: openings are formed in the shell wall corresponding to the liquid area inside each liquid level sensor, and each opening is communicated with the liquid area of the same closed container through a communicating container or is submerged in the liquid area of the same closed container; openings are formed in the shell wall corresponding to a gas area above the liquid level in each liquid level sensor, and each opening is communicated with each other through a vent pipe or is opened in the gas area of the same closed container;
the first end of the hollow coaxial cable-Fabry-Perot resonant cavity of each liquid level sensor is at the bottom: openings are formed in the shell wall corresponding to the liquid area inside each liquid level sensor, and communication containers are used for communication among the openings; openings are formed in the housing wall corresponding to the gas region above the liquid level in each liquid level sensor, and a vent pipe is used for communication between each opening.
In one embodiment of the present application, the inclinometer comprises a liquid level sensor, the inclinometer is a unidirectional inclinometer, and the first end of the hollow coax-fabry-perot resonator of the liquid level sensor is located at the top, wherein:
the second end of the hollow coaxial cable-Fabry-Perot resonant cavity of the liquid level sensor is of an open structure, the open structure is connected with a U-shaped pipe, the liquid level sensor is communicated with a liquid area in the U-shaped pipe, and the liquid level sensor is communicated with a gas area above the liquid level of the U-shaped pipe through a vent pipe and used for eliminating the gas pressure difference between the liquid level sensor and the gas area of the U-shaped pipe;
fixing the inclinometer on a measured object, wherein the first reflection point is positioned above the second reflection point; when the inclination angle of the inclinometer changes on a plane formed by the liquid level sensor and the axis of the U-shaped pipe, the liquid level in the liquid level sensor changes, so that the length of a resonant cavity between the first reflection point and the second reflection point changes, and the included angle between the liquid level of the liquid and the axis of the liquid level sensor changes, wherein the liquid level of the liquid is maintained on a horizontal plane; the tilt angle may be determined by measuring the amount of change in the resonator length and then performing temperature compensation.
In an embodiment of the present application, the inclinometer includes two liquid level sensors, the inclinometer is a unidirectional inclinometer that does not need temperature compensation and rotates along with the measured object, the first ends of the hollow coaxial cable-fabry perot resonant cavities of the two liquid level sensors are all located at the top, wherein:
the two liquid level sensors are arranged in parallel and vertically, liquid areas in the two liquid level sensors are communicated by using a communicating container, and gas areas above the liquid level of the two liquid level sensors are communicated by using a vent pipe and are used for eliminating the pressure difference between the gas areas above the liquid level in the two liquid level sensors;
the inclinometer is fixed on a measured object, and first reflection points of the two liquid level sensors are both positioned above second reflection points; the initial cavity lengths of the two liquid level sensors are respectively L1And L2The parallel distance between the axes of the two liquid level sensors is d; when the inclination angle of the inclinometer changes on the plane formed by the axes of the two liquid level sensors, the liquid levels in the two liquid level sensors change, so that the length of a resonant cavity between a first reflection point and a second reflection point of the two liquid level sensors changes, and the change amounts are respectively delta L1And Δ L2(ii) a Difference value Delta L of resonant cavity length variation of the two liquid level sensors2-ΔL1And the magnitude of the parallel distance d, it is determined that the amount of change in the tilt angle is Δ θ ═ arctan [ (Δ L)2-ΔL1)/d]。
In an embodiment of the present application, the inclinometer includes two liquid level sensors, the inclinometer is a unidirectional inclinometer that does not need temperature compensation and rotates along with the measured object, the first ends of the hollow coaxial cable-fabry perot resonant cavities of the two liquid level sensors are all located at the bottom, wherein:
the two liquid level sensors are arranged in parallel and vertically, a sealing plug is arranged in each of the bodies of the two liquid level sensors and used for ensuring that liquid is above the sealing plug, the top of the sealing plug or the bottom of the liquid is used as a first reflection point, the top of the liquid is used as a second reflection point, and the top of the liquid is always lower than the tops of the shell and the inner rod; the shell wall corresponding to the liquid areas in the two liquid level sensors is provided with an opening which is positioned below the liquid level and above the sealing plug, and the two openings are communicated with the communicating container to enable the liquid areas in the two liquid level sensors to be communicated; the gas areas above the liquid levels of the two liquid level sensors are communicated by using a vent pipe and are used for eliminating the gas pressure difference between the gas areas above the liquid levels in the two liquid level sensors;
the inclinometer is fixed on a measured object, and first reflection points of the two liquid level sensors are both positioned below second reflection points; the initial cavity lengths of the two liquid level sensors are respectively L1And L2The parallel distance between the axes of the two liquid level sensors is d; when the inclination angle of the inclinometer is changed on the plane formed by the axes of the two liquid level sensors, the liquid levels in the two liquid level sensors are changed, the bottom surface position of the liquid is unchanged, the position of the top surface of the liquid is changed, so that the length of a resonant cavity between the first reflection point and the second reflection point of the two liquid level sensors is changed, and the change amounts are respectively delta L1And Δ L2(ii) a Difference value Delta L of resonant cavity length variation of the two liquid level sensors2-ΔL1And the magnitude of the parallel distance d, it is determined that the tilt angle change amount is [ Δ θ ] ═ arctan [ (Δ L)2-ΔL1)/d]。
In an embodiment of the present application, the inclinometer includes two liquid level sensors, the inclinometer is a unidirectional inclinometer without temperature compensation, when the inclination angle of the inclinometer changes, the two liquid level sensors do not rotate, the first ends of the hollow coaxial cable-fabry perot resonant cavities of the two liquid level sensors are all located at the top, wherein:
the two liquid level sensors are arranged in parallel, the two liquid level sensors are respectively fixed on the substrate through a rotating shaft, so that the two liquid level sensors can rotate around the rotating shaft, the rotating shaft is arranged below the second reflection point, the rotating shaft is positioned on the axis of the liquid level sensors, and the connecting line of the rotating shafts of the two liquid level sensors is perpendicular to the axes of the two liquid level sensors; the bottom of each liquid level sensor is provided with a heavy hammer for ensuring that the axis of the liquid level sensor is always vertical when the base plate is driven to rotate after the inclination angle of the inclinometer is changed;
liquid areas in the two liquid level sensors are communicated by using a communicating container, and gas areas above the liquid levels of the two liquid level sensors are communicated by using a vent pipe, so that the pressure difference between the gas areas above the liquid levels in the two liquid level sensors is eliminated; wherein, the communicating container and the vent pipe both adopt flexible pipes to ensure that the liquid level sensor is not driven to rotate; or the whole system is placed into a closed container, liquid is filled at the bottom of the closed container, parts of the shells and the inner rods of the two liquid level sensors are always immersed into the liquid at the bottom of the closed container, liquid areas in the two liquid level sensors are communicated with the liquid at the bottom of the closed container, and gas areas of the two liquid level sensors are communicated with gas above the liquid level of the closed container, so that the pressure difference between the gas areas above the liquid level in the two liquid level sensors is eliminated;
the inclinometer is fixed on a measured object, and first reflection points of the two liquid level sensors are both positioned above second reflection points; the initial cavity lengths of the two liquid level sensors are respectively L1And L2The distance between the two rotating shafts corresponding to the two liquid level sensors is L; when the inclination angle of the inclinometer changes on a plane formed by the axes of the two liquid level sensors, the axes of the two liquid level sensors are vertical all the time under the action of the heavy hammer, the liquid levels in the two liquid level sensors change, so that the length of a resonant cavity between a first reflection point and a second reflection point of the two liquid level sensors changes, and the change amount is respectively delta L1And Δ L2(ii) a Difference value Delta L of resonant cavity length variation of the two liquid level sensors2-ΔL1And the distance L between the two rotating shafts on the substrate, and determining the inclination angle change delta theta as arcsin [ (delta L)2-ΔL1)/L]。
In an embodiment of the present application, the inclinometer includes two liquid level sensors, the inclinometer is a unidirectional inclinometer without temperature compensation, when the inclination angle of the inclinometer changes, the two liquid level sensors do not rotate, the first ends of the hollow coaxial cable-fabry perot resonant cavities of the two liquid level sensors are all located at the top, wherein:
the inclinometer comprises a closed container, two flexible ropes or two groups of flexible ropes with equal length are fixed on the top plate of the closed container, and a liquid level sensor is hung below each flexible rope or each group of flexible ropes, wherein a demodulation device of the liquid level sensor is arranged at the top of a hollow coaxial cable-Fabry-Perot resonant cavity and is hung below the flexible ropes, and the axis of the hung liquid level sensor is in the vertical direction; the bottom of the closed container is filled with liquid, parts of the shells and the inner rod of the two liquid level sensors are always immersed in the liquid at the bottom of the closed container, liquid areas in the two liquid level sensors are communicated with the liquid at the bottom of the closed container, and air holes are formed in the shell walls or the first ends of the shell walls corresponding to the gas areas of the two liquid level sensors, so that the gas areas in the liquid level sensors are communicated with the gas above the liquid level of the closed container and are used for eliminating the air pressure difference between the gas areas above the liquid level in the two liquid level sensors;
fixing the inclinometer on a measured object, wherein the first reflection point is positioned above the second reflection point; the initial cavity lengths of the two liquid level sensors are respectively L1And L2The distance between the fixed points of the two flexible ropes on the top plate is L; work as the inclination of inclinometer is in when changing on the plane that two level sensor's axis constitutes, two level sensor's axis is vertical all the time under the action of gravity, liquid level among two level sensor changes, leads to resonant cavity between two level sensor's first reflection point and the second reflection point is long to be changed, and the change quantity is delta L respectively1And Δ L2(ii) a Difference value Delta L of resonant cavity length variation of the two liquid level sensors2-ΔL1And the distance L between the two flexible ropes and the fixed points on the top plate is largeWhen the tilt angle change amount Δ θ is small, arcsin [ (Δ L) can be determined2-ΔL1)/L]。
In an embodiment of the present application, the inclinometer includes two liquid level sensors, the inclinometer is a unidirectional inclinometer that does not need temperature compensation and rotates along with the measured object, the first ends of the hollow coaxial cable-fabry perot resonant cavities of the two liquid level sensors are all located at the top, wherein:
the inclinometer comprises a closed container, wherein the two liquid level sensors are arranged in parallel and are rigidly fixed on the top plate or the bottom plate or the side surface of the closed container; the bottom of the closed container is filled with liquid, parts of the shells and the inner rod of the two liquid level sensors are always immersed in the liquid at the bottom of the closed container, liquid areas in the two liquid level sensors are communicated with the liquid at the bottom of the closed container, and air holes are formed in the shell walls or the first ends of the shell walls corresponding to the gas areas of the two liquid level sensors, so that the gas areas in the liquid level sensors are communicated with the gas above the liquid level of the closed container and are used for eliminating the air pressure difference between the gas areas above the liquid level in the two liquid level sensors;
fixing the inclinometer on a measured object, wherein the first reflection point is positioned above the second reflection point; the initial cavity lengths of the two liquid level sensors are respectively L1And L2The parallel distance between the axes of the two liquid level sensors is d; when the inclination of inclinometer is in when changing on the plane that two level sensor's axis constitutes, two level sensor follow the inclinometer takes place to rotate and removes, liquid level among two level sensor changes, leads to resonant cavity length between two level sensor's first reflection point and the second reflection point changes, and the change quantity is delta L respectively1And Δ L2(ii) a Difference value Delta L of resonant cavity length variation of the two liquid level sensors2-ΔL1And the size of the parallel distance d between the axis, the inclination angle change amount delta theta is determined to be arctan [ (delta L)2-ΔL1)/d]。
In an embodiment of the present application, the inclinometer includes three liquid level sensors, the inclinometer is a bidirectional inclinometer that does not need temperature compensation and rotates along with the measured object, the first end of the hollow coaxial cable-fabry perot resonator of the three liquid level sensors is located at the top, wherein:
the three liquid level sensors are arranged in parallel and vertically, and the axes of the three liquid level sensors and three intersection points of a horizontal plane are not on the same straight line; liquid areas in the three liquid level sensors are communicated by using a communicating container; for gas areas above the liquid level inside the three liquid level sensors, a first liquid level sensor is communicated with a second liquid level sensor through a first vent pipe, a third liquid level sensor is communicated with the second liquid level sensor through a second vent pipe, and the first vent pipe and the second vent pipe are located above the liquid level and used for eliminating the gas pressure difference among the gas areas above the liquid level inside the three liquid level sensors;
fixing the inclinometer on a measured object, wherein first reflection points of the three liquid level sensors are all positioned above second reflection points; the initial cavity lengths of the three liquid level sensors are respectively L1、L2And L3When three intersection points of the axes of the three liquid level sensors and the horizontal plane form a right triangle, two right-angle sides are respectively an X axis and a Y axis in the inclined direction; the parallel distance between the axes of the first liquid level sensor and the second liquid level sensor is d1The parallel distance between the axes of the second level sensor and the third level sensor is d2(ii) a When the inclinometer inclines around the X axis and the Y axis, the length of the resonant cavity between the first reflection point and the second reflection point of the first liquid level sensor and the second liquid level sensor changes, and the change amounts are respectively delta L1And Δ L2Difference DeltaL of resonant cavity length variation by two liquid level sensors2-ΔL1And a parallel spacing d1Can determine the inclination angle variation delta theta of the inclinometer around the X axis1＝arctan[(ΔL2-ΔL1)/d1](ii) a Second and third level sensorsThe length of the resonant cavity between the first reflection point and the second reflection point of the resonator is also changed by Δ L2And Δ L3Difference DeltaL of resonant cavity length variation by two liquid level sensors3-ΔL2And a parallel spacing d2Can determine the variation delta theta of the inclination angle of the inclinometer around the Y axis2＝arctan[(ΔL3-ΔL2)/d2]。
In an embodiment of the present application, the inclinometer includes three liquid level sensors, the inclinometer is a bidirectional inclinometer without temperature compensation, when the inclination angle of the inclinometer changes, the three liquid level sensors do not rotate, the first ends of the hollow coaxial cable-fabry perot resonant cavities of the three liquid level sensors are all located at the top, wherein:
the inclinometer comprises a closed container, three flexible ropes or three groups of flexible ropes with equal length are fixed on a top plate of the closed container, and a liquid level sensor is hung below each flexible rope or each group of flexible ropes, wherein a demodulation device of the liquid level sensor is arranged at the top of a hollow coaxial cable-Fabry-Perot resonant cavity and is hung below the flexible ropes, and the axis of the hung liquid level sensor is in the vertical direction; the three intersection points of the axes of the three liquid level sensors and the horizontal plane are not on the same straight line; the bottom of the closed container is filled with liquid, a part of the outer shell and the inner rod of the three liquid level sensors is always immersed in the liquid at the bottom of the closed container, liquid areas in the three liquid level sensors are communicated with the liquid at the bottom of the closed container, and air vents are arranged on the shell wall or the first end of the shell wall corresponding to the gas areas of the three liquid level sensors, so that the gas areas in the liquid level sensors are communicated with the gas above the liquid level of the closed container and are used for eliminating the air pressure difference between the gas areas above the liquid level in the three liquid level sensors;
fixing the inclinometer on a measured object, wherein the first reflection point is positioned above the second reflection point; the initial cavity lengths of the three liquid level sensors are respectively L1、L2And L3When the axes of the three level sensors areWhen three intersection points of the line and the horizontal plane form a right triangle, two right-angle sides are respectively an X axis and a Y axis in the inclined direction; the parallel distance between the axes of the first liquid level sensor and the second liquid level sensor is d1The parallel distance between the axes of the second level sensor and the third level sensor is d2(ii) a When the inclinometer inclines around the X axis and the Y axis, the length of the resonant cavity between the first reflection point and the second reflection point of the first liquid level sensor and the second liquid level sensor changes, and the change amounts are respectively delta L1And Δ L2Difference DeltaL of resonant cavity length variation by two liquid level sensors2-ΔL1And a parallel spacing d1Can determine the inclination angle variation delta theta of the inclinometer around the X axis1＝arcsin[(ΔL2-ΔL1)/d1](ii) a The length of the resonant cavity between the first reflection point and the second reflection point of the second liquid level sensor and the third liquid level sensor is also changed, and the change amounts are respectively delta L2And Δ L3Difference DeltaL of resonant cavity length variation by two liquid level sensors3-ΔL2And a parallel spacing d2Can determine the variation delta theta of the inclination angle of the inclinometer around the Y axis2＝arcsin[(ΔL3-ΔL2)/d2]。
In an embodiment of the present application, the inclinometer includes three liquid level sensors, the inclinometer is a bidirectional inclinometer that does not need temperature compensation and rotates along with the measured object, the first end of the hollow coaxial cable-fabry perot resonator of the three liquid level sensors is located at the top, wherein:
the inclinometer comprises a closed container, the three liquid level sensors are arranged in parallel and are rigidly fixed on a top plate, a bottom plate or a side surface of the closed container, and three intersection points of the axes of the three liquid level sensors and a horizontal plane are not on the same straight line; the bottom of the closed container is filled with liquid, a part of the outer shell and the inner rod of the three liquid level sensors is always immersed in the liquid at the bottom of the closed container, liquid areas in the three liquid level sensors are communicated with the liquid at the bottom of the closed container, and air vents are arranged on the shell wall or the first end of the shell wall corresponding to the gas areas of the three liquid level sensors, so that the gas areas in the liquid level sensors are communicated with the gas above the liquid level of the closed container and are used for eliminating the air pressure difference between the gas areas above the liquid level in the three liquid level sensors;
fixing the inclinometer on a measured object, wherein the first reflection point is positioned above the second reflection point; the initial cavity lengths of the three liquid level sensors are respectively L1、L2And L3When three intersection points of the axes of the three liquid level sensors and the horizontal plane form a right triangle, two right-angle sides are respectively an X axis and a Y axis in the inclined direction; the parallel distance between the axes of the first liquid level sensor and the second liquid level sensor is d1The parallel distance between the axes of the second level sensor and the third level sensor is d2(ii) a When the inclinometer inclines around the X axis and the Y axis, the length of the resonant cavity between the first reflection point and the second reflection point of the first liquid level sensor and the second liquid level sensor changes, and the change amounts are respectively delta L1And Δ L2Difference DeltaL of resonant cavity length variation by two liquid level sensors2-ΔL1And a parallel spacing d1Can determine the inclination angle variation delta theta of the inclinometer around the X axis1＝arctan[(ΔL2-ΔL1)/d1](ii) a The length of the resonant cavity between the first reflection point and the second reflection point of the second liquid level sensor and the third liquid level sensor is also changed, and the change amounts are respectively delta L2And Δ L3Difference DeltaL of resonant cavity length variation by two liquid level sensors3-ΔL2And a parallel spacing d2Can determine the variation delta theta of the inclination angle of the inclinometer around the Y axis2＝arctan[(ΔL3-ΔL2)/d2]。
In one embodiment of the present application, three intersection points of the axes of the three level sensors and the horizontal plane are not on a straight line, and at least include:
the axes of the three liquid level sensors and three intersection points of the horizontal plane form a right triangle, and the two right-angle sides are respectively an X rotating shaft and a Y rotating shaft in the inclined direction.
In one embodiment of the present application, when three intersection points of the axes of the three level sensors and the horizontal plane form an isosceles right triangle, d1＝d2。
In an embodiment of the present application, when the inclinometer includes N level sensors, N is an integer greater than or equal to 4, the axes of the N level sensors are not on the same straight line with N intersections of the horizontal plane, and then the inclinometer can be regarded as a bidirectional inclinometer without temperature compensation.
Drawings
Fig. 1 is a schematic diagram of a hollow coax fabry-perot resonator according to an embodiment of the present disclosure;
FIG. 2(a) is a schematic diagram of a hollow coaxial cable-Fabry-Perot resonator without an inner rod;
FIG. 2(b) is a schematic structural diagram of a hollow coaxial cable-Fabry-Perot resonator including an inner rod;
FIG. 3 is a reflection amplitude spectrum and a transmission amplitude spectrum of a hollow coax Fabry-Perot resonator according to an embodiment of the present application;
FIG. 4 is a cross-sectional view of the housing in general;
FIG. 5 is a cross-sectional view of the inner rod in use;
FIG. 6 is a cross-sectional view of a conventional reflection point;
FIG. 7 is a schematic view of the junction of the outer shell or the inner rod with the outer shell or the inner rod;
FIG. 8(a) is a schematic structural diagram of a reflective cavity length measuring device with a coaxial cable and a demodulation device according to an embodiment of the present application;
FIG. 8(b) is a schematic structural diagram of a cavity length measuring device of the present application, in which the demodulation device is directly connected to the sensor;
FIG. 9(a) is a schematic diagram of a loop structure of a first transmission or positive feedback loop type cavity length measuring device according to an embodiment of the present application;
FIG. 9(b) is a schematic diagram of a loop structure of a second transmission or positive feedback loop type cavity length measuring device according to an embodiment of the present application;
FIG. 9(c) is a schematic diagram of a loop structure of a third transmission or positive feedback loop type cavity length measuring device according to an embodiment of the present application;
FIG. 9(d) is a schematic diagram of a loop structure of a fourth transmission or positive feedback loop type cavity length measuring device according to an embodiment of the present application;
FIG. 10(a) is a schematic structural diagram of a cavity length measuring apparatus according to an embodiment of the present application;
FIG. 10(b) is a schematic structural diagram of the liquid level sensor with the liquid level as the second reflecting surface and without energy dissipation systems at the ends of the outer shell and the inner rod in the embodiment of the present application;
fig. 10(c) is a schematic structural diagram of the liquid level sensor when a floating object on the liquid surface is used as a second reflecting surface and no energy dissipation system is arranged at the end parts of the outer shell and the inner rod according to the embodiment of the application;
FIG. 10(d) is a schematic structural diagram of a cavity length measuring device for connecting coaxial loads at the ends of an outer shell and an inner rod of the embodiment of the present application;
FIG. 10(e) is a schematic structural diagram of a level sensor with a second reflection of the liquid level and an end connected to a coaxial load according to an embodiment of the present application;
FIG. 10(f) is a schematic structural diagram of a cavity length measuring device in which the ends of the outer shell and the inner rod of the present application are connected to a load resistor;
FIG. 10(g) is a schematic diagram of a liquid level sensor with a second reflection of the liquid level and a load resistor connected to the end of the sensor according to an embodiment of the present application;
FIG. 11 is a schematic view of an inclinometer formed by using a liquid level sensor and a U-shaped pipe according to an embodiment of the present application;
FIG. 12(a) is a schematic structural diagram of a first level difference-based inclinometer according to the embodiment of the present application;
FIG. 12(b) is a schematic structural diagram of a first inclinometer based on a liquid level difference and provided with load resistors at the ends of two liquid level sensors in the embodiment of the present application;
FIG. 12(c) is a schematic structural diagram of a first inclinometer based on a liquid level difference and with coaxial loads at the ends of two liquid level sensors in the embodiment of the present application;
FIG. 12(d) is a schematic structural diagram of a first inclinometer based on a liquid level difference and using the upper and lower surfaces of a liquid as two reflection points in the embodiment of the present application;
FIG. 13(a) is a schematic diagram of a second type of inclinometer according to the embodiment of the present application, in which the end of the level sensor is open or connected to a load resistor, and the axis of the level sensor is always kept vertical;
FIG. 13(b) is a schematic diagram of a second type of inclinometer according to the embodiment of the present application, in which the end of the level sensor is sealed or connected to a coaxial load, and the axis of the level sensor is always kept vertical;
FIG. 14(a) is a schematic diagram of a third inclinometer structure in the embodiment of the present application, in which the end of the suspended type liquid level sensor is open or connected with a load resistor, and the axis of the liquid level sensor is always kept vertical, based on the liquid level difference;
FIG. 14(b) is a schematic diagram of a third inclinometer structure in the embodiment of the present application, in which the end of the suspended type liquid level sensor is sealed or connected with a coaxial load based on a liquid level difference, and the axis of the liquid level sensor is always kept vertical;
FIG. 15(a) is a schematic structural diagram of a bidirectional inclinometer based on a liquid level difference and with three liquid level sensors open at ends or with load resistors in the embodiment of the application;
FIG. 15(b) is a schematic structural diagram of a bidirectional inclinometer based on a liquid level difference and with three liquid level sensors open at ends or with coaxial loads in the embodiment of the application;
FIG. 16(a) is a bird's eye view of a bi-directional inclinometer made by using three liquid level sensors according to the embodiment of the present application;
FIG. 16(b) is a bird's eye view of a bi-directional inclinometer made by using four liquid level sensors according to the embodiment of the present application;
FIG. 17(a) is a schematic structural view of a bidirectional inclinometer implemented by using three suspended liquid level sensors and adopting the energy dissipation principle of the end part of a load resistor according to the embodiment of the present application;
FIG. 17(b) is a schematic structural view of a bi-directional inclinometer implemented using three suspended level sensors and using the coaxial load end energy dissipation principle according to the embodiment of the present application;
description of reference numerals:
1-a housing, which can be a hollow tube, a rod, a spring or a continuous conductor of other shape; 2-the inner rod can be hollow or solid, and can also be a spring or a continuous conductor with other shapes; 3-the first reflection point can be a conductor or an insulator, can be connected with the outer shell or the inner rod, can also be unconnected, and can be in any shape or a combination of a plurality of parts; 4-a second reflection point having the same attribute as the first reflection point; 5-a resonant cavity, the interior of which can be gas or liquid; 6-radio frequency coaxial cable adapter; 7-a central signal pin of the coaxial cable adapter; 8-coaxial cable for transmission; 9-demodulation means comprising a vector network analyzer, or a scalar microwave analyzer, or a circuit for measuring and demodulating the spectrum; 11-left end tube or rod butt joint part; 12-right end tube or rod butt joint part; 13-a rotating shaft made of a conductor; 14-conductor bellows, multipurpose metal; 15-the end devices of the outer shell 1 and the inner rod 2 can be conductors, insulators, closed or non-closed structures, and can be coaxial loads or load resistors as the ends; 16-radio frequency coaxial cable adapter; 22-load resistance; 23-coaxial load; 30-a container for holding a liquid, which can be of various shapes, including tubular; 31-a liquid; 32-vent, or vent (opening in the sensor housing wall); 33-a rotating shaft for fixing the sensor on the object to be measured, so that the movement of the liquid level sensor is limited, and the rotation of the liquid level sensor around the rotating shaft is not limited; 34-soft material containing liquid, such as a hose; 35-a main body of the object to be measured or a substrate to which the inclinometer is fixed, to which the rotating shaft 33 is fixed; 36-a hose; 37-a connecting device for fixing the weight on the liquid level sensor; 38-weight; 39-a sealing plug for isolating liquid, the material can be selected from an insulator or a conductor with larger resistivity; 40-a liquid-communicating vessel, i.e. a communicating vessel; 41-hose shell; 42-the connection of the liquid area of the housing to the outside liquid, which may be a hole in the wall of the housing; 43-flexible cord or rigid rod; 50-demodulation system, which refers to the generic term for the instrument for demodulating the cavity length, including all the demodulation instruments and circuit boards based on reflection, or transmission, or loop, and the transmission coaxial cable for the sensor connected to the demodulation instrument; 51-a single level sensor comprising a sensor body and a demodulation system; 52-a top plate; 61-first level sensor; 62-a second level sensor; 63-a third level sensor; 64-fourth level sensor.
Detailed Description
The embodiment of the application provides a novel cavity length measuring device of a microwave resonant cavity, wherein the microwave resonant cavity is specifically a hollow coaxial cable-Fabry-Perot resonant cavity, and the cavity length measuring device of the embodiment of the application can measure the cavity length of the hollow coaxial cable-Fabry-Perot resonant cavity. This application embodiment combines chamber length measuring device and supplementary mechanical design, can change chamber length measuring device into level sensor, designs the inclinometer of this application embodiment based on level sensor.
In the technical scheme of this application embodiment, level sensor can measure the liquid level size by the high accuracy based on mechanical transmission structure, and the principle of measurement is based on the principle of hollow coaxial cable-fabry-perot resonant cavity, and here, hollow coaxial cable-fabry-perot resonant cavity includes: the liquid level measuring device comprises a shell, an inner rod (optional), a resonant cavity and two reflecting points, wherein the resonant cavity is convenient to manufacture in structure, and the liquid level under the static force and the dynamic force can be measured by utilizing the movement of the reflecting points in the resonant cavity. In addition, the temperature compensation of the inclinometer designed based on the liquid level sensor is very convenient and is not influenced by factors such as electromagnetism. The inclinometer of the application mostly does not need temperature compensation, and under the condition that the temperature compensation is needed, the temperature compensation can be carried out through the thermometer, so that the common monitoring of the inclination angle and the temperature can be realized. The inclinometer designed by the embodiment of the application has the advantages of high precision, strong anti-interference capability, strong durability and the like, has wide application prospect, and is particularly suitable for measuring the inclination angle of a structure under the static and dynamic actions at high precision. Because the material performance that the inclinometer adopted is stable, can realize easily working between sixty degrees below zero to hundreds of degrees above zero, can work in a bigger temperature range through changing the preparation material. In summary, the inclinometer of the embodiment of the application is not interfered by any electromagnetic signal, the influence of temperature on the inclinometer is extremely small, and temperature compensation is very easy to realize.
The hollow coaxial cable-fabry-perot resonant cavity in the embodiment of the application is similar to a conventional optical fabry-perot resonant cavity, and is different from the optical fabry-perot resonant cavity in that the hollow coaxial cable-fabry-perot resonant cavity is manufactured based on a radio frequency coaxial cable and is a sensor based on a microwave principle.
In the embodiment of the present application, the two reflection points are high reflection points, where the reflectivity of the high reflection points is generally higher than 50%, and less than 50% in a few cases, but not lower than 20%, and each reflection point has a high reflectivity, so that it is not suitable for being made into a distributed sensor. The Fabry-Perot resonant cavity belongs to a resonance phenomenon caused by multipath interference, and has the characteristics of high demodulation precision, high signal-to-noise ratio, high cost performance of a demodulation device and the like.
In the embodiment of the application, a brand-new self-processing hollow coaxial cable-Fabry-Perot resonant cavity platform is provided, an internal insulator of the hollow coaxial cable-Fabry-Perot resonant cavity is generally air, and liquid can be filled in the hollow coaxial cable-Fabry-Perot resonant cavity platform in special application.
So that the manner in which the features and elements of the present embodiments can be understood in detail, a more particular description of the embodiments, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings.
Fig. 1 is a schematic diagram of a fabry-perot resonator according to an embodiment of the present disclosure. As shown in fig. 1, two reflection points with high reflectivity (the two reflection points are referred to as a first reflection point 3 and a second reflection point 4) are disposed inside a hollow coax-fabry-perot resonator 5, wherein the first reflection point 3 is disposed at a first position inside the hollow coax-fabry-perot resonator 5, the second reflection point 4 is disposed at a second position inside the hollow coax-fabry-perot resonator 5, and the distance between the two reflection points generally exceeds 1 cm.
Here, the hollow coaxial cable-fabry-perot resonator is mostly composed of an outer conductor (i.e. outer shell) and an inner conductor (i.e. inner rod), as shown in fig. 1, the outer shell 1 and the inner rod 2 are both continuous conductors: a single conductive part, or a plurality of conductive parts. In an embodiment, there may be only the outer shell 1, without the inner rod 2. In another embodiment, both the outer shell 1 and the inner rod 2 may be provided.
The medium in the resonant cavity between the outer shell 1 and the inner rod 2 is one of the following: vacuum, gas, liquid, solid; wherein, when the medium is a solid, the solid is filled out of the range in which the reflection point moves. Electromagnetic waves traveling in the hollow coaxial cable-Fabry-Perot resonant cavity are mainly reflected on the first reflection point, a part of energy is reflected, and the rest of energy is transmitted to the second reflection point. At the second reflection point, a small portion of the electromagnetic wave is reflected again and repeated multiple round trips (the number of round trips is determined by the reflectivity of the reflection point). The higher the reflectivity of the two reflection points, the more the number of round trips, and the higher the quality factor of the reflection amplitude spectrum or the transmission amplitude spectrum of the resonant cavity. In the above solution, the reflection point may be generated by an impedance deviation of the coaxial cable, or by a short circuit or an open circuit of the inner and outer conductors. Two reflection points can generate a phase delay delta of microwave, and the calculation formula is as follows:
Figure DEST_PATH_GDA0002252650310000111
wherein f is the microwave frequency, εrIs the dielectric constant of the material inside the coaxial cable (air is 1), d is the frequency of the resonant cavity, and c is the speed of light in vacuum.
The amplitude spectra of the reflected and transmitted electric fields of a hollow coaxial cable-fabry-perot resonator are represented by the following formula:
Figure DEST_PATH_GDA0002252650310000112
Figure DEST_PATH_GDA0002252650310000113
wherein r is the reflection amplitude spectrum, and t is the transmission amplitude spectrum. R is the reflectivity of the reflection point, and equation (2) assumes that the reflectivities of the two reflection points are the same and the insertion loss of the fabry-perot resonator is zero.
Fig. 3 shows a reflection amplitude spectrum and a transmission amplitude spectrum of the fabry-perot resonator according to an embodiment of the present disclosure. As shown in fig. 3, a plurality of resonant frequencies can be observed, including fundamental and harmonic. Many small ripples can be observed in fig. 3(a) and (b) due to reflections caused by imperfect impedance matching between the instrument interface and the coaxial cable. The basic idea of using a hollow coaxial cable-fabry-perot resonator for making a sensor is based on the fact that the distance between two reflection points can be accurately calculated from the reflection amplitude spectrum or the transmission amplitude spectrum.
The following describes in detail a cavity length measuring apparatus of a microwave resonant cavity according to an embodiment of the present application with reference to a specific structure, and the cavity length measuring apparatus according to the embodiment of the present application includes: a microwave resonant cavity and a demodulation device, wherein the microwave resonant cavity refers to a hollow coaxial cable-Fabry-Perot resonant cavity shown in figure 1. In all embodiments of the present application:
1) the outer shell 1/inner rod 2 can be a conductor part, or a plurality of conductor parts are connected together (to ensure the conductivity of the connection), and therefore, the outer shell 1/inner rod 2 is a continuous conductor. One conductor part shown in all the drawings does not necessarily represent a simple conductor part, but may represent a composite conductor part in which a plurality of conductor parts are combined by different connection means.
2) With respect to the movement of the second reflection point:
2.1) when the outer shell and the inner rod are provided, the second reflecting point can be moved independently, or the second reflecting point can be fixed with the outer shell and/or the inner rod, and then the outer shell and/or the inner rod and the second reflecting point are moved together to realize the movement of the second reflecting point. When the outer shell and/or the inner rod and the second reflection point are fixed into a whole, the second reflection point is moved to cause that part of the outer shell and/or the inner rod is moved, and the outer shell and/or the inner rod must ensure the conductive connectivity, so that the outer shell and/or the inner rod are required to be used in a nested structure, a spring structure or a corrugated pipe structure and the like which can adapt to larger stretching or compression and can keep the conductive continuity. The liquid level sensor mentioned in the embodiments of the application may use such a structure.
2.2) when the outer shell has no inner rod, the second reflecting point can be moved independently, or the second reflecting point and the outer shell can be fixed, and then the outer shell and the second reflecting point are moved together to realize the movement of the second reflecting point. When the housing and the second reflection point are fixed into a whole, the second reflection point is moved to cause the partial housing to move, and the housing must ensure the conductive connectivity, so the housing needs to be used in a nested structure, a spring structure or a corrugated pipe structure, and the like, which can adapt to larger stretching or compression and can maintain the conductive continuity.
3) When a positive feedback loop structure is adopted, two reflecting points can be used, and the measured length is the equivalent distance between the two reflecting points; there may also be only one reflection point and the measured length is the perimeter of the positive feedback loop.
The first embodiment is as follows: cavity length measuring device of microwave resonant cavity
The cavity length measuring device includes: a microwave resonant cavity and a demodulation device; the microwave resonant cavity comprises a hollow coaxial cable-Fabry-Perot resonant cavity, a first reflection point and a second reflection point, wherein the first reflection point is arranged at a first position inside the hollow coaxial cable-Fabry-Perot resonant cavity, the second reflection point is arranged at a second position inside the hollow coaxial cable-Fabry-Perot resonant cavity, and the first position and/or the second position can be moved; the total reflectivity of the first reflection point and the second reflection point is greater than or equal to a preset threshold value; the demodulation device is connected with the microwave resonant cavity and used for analyzing the microwave signals in the microwave resonant cavity to obtain the cavity length of the microwave resonant cavity, wherein the cavity length of the microwave resonant cavity is the distance between the first reflection point and the second reflection point. Alternatively, the microwave cavity comprises a positive feedback loop, which may have two reflection points, one reflection point or no reflection point. The demodulation means are arranged to measure the circumference of the positive feedback loop when there is only one reflection point or no reflection point in the positive feedback loop.
The cavity length measuring device in this embodiment is classified into the following three types:
1) a reflective cavity length measuring device, in which:
one end of the hollow coaxial cable-Fabry-Perot resonant cavity is connected to a radio frequency coaxial cable adapter, and the radio frequency coaxial cable adapter is connected to the demodulation device through a coaxial cable; one end of the resonant cavity may also be directly connected to a demodulating device, wherein the demodulating device 9 is: a vector network analyzer, or a microwave generating source plus a scalar network analyzer, or a microwave time domain reflectometer, or a demodulation circuit (such as a circuit board with a demodulation function); the other end of the hollow coaxial cable-Fabry-Perot resonant cavity is of an open structure, or a sealing structure, or is connected with energy dissipation structures such as a coaxial load or a load resistor and the like.
2) A transmissive cavity length measuring device, in which:
the first end of the hollow coaxial cable-Fabry-Perot resonant cavity is connected to a first radio-frequency coaxial cable adapter, the shell wall of the hollow coaxial cable-Fabry-Perot resonant cavity is connected to a second radio-frequency coaxial cable adapter, and the first radio-frequency coaxial cable adapter and the second radio-frequency coaxial cable adapter are connected with the demodulation device through coaxial cables; the outer shell and the inner rod at the first end of the resonant cavity can also be directly connected to the demodulating device without a radio frequency coaxial cable for transmitting signals.
Here, the cavity length measuring device has at least the following modes: a positive feedback loop mode, a loop-free mode; wherein the content of the first and second substances,
in the positive feedback loop mode, the demodulation apparatus includes: a directional coupler, a waveform amplifier, a frequency counter/frequency spectrograph; in addition, in the positive feedback loop mode, there may be two reflection points, or only one reflection point, or no reflection point; when there is only one reflection point or no reflection point, the measured cavity length is the circumference of the loop.
In the loop-free mode, the demodulation device 9 is a vector network analyzer, a scalar microwave analyzer, or a demodulation circuit.
Further, the positive feedback loop mode includes: a microwave positive feedback loop and a positive feedback loop based on a photoelectric oscillator; wherein the content of the first and second substances,
in the microwave positive feedback loop, comprising: coaxial cable loop, microwave directional coupler, microwave amplifier or microwave power separator, frequency counter/frequency spectrograph;
in the optoelectronic oscillator based positive feedback loop, comprising: the device comprises a high-speed photoelectric demodulator, a laser or light emitting diode light source, an optical fiber loop, an optical fiber coupler, a microwave amplifier or an optical amplifier, a microwave directional coupler or a microwave power splitter and a frequency counter/frequency spectrograph, wherein all devices in the demodulating device are connected through the optical fiber loop.
In this embodiment, the numbers of the core devices are as follows: shell 1, interior pole 2, first reflection point 3, second reflection point 4, resonant cavity 5, radio frequency coaxial cable adapter 6 and 16, vector network analysis appearance or scalar microwave analysis appearance, or the circuit 9 of measuring and demodulation frequency spectrum, load resistance 22, coaxial load 23, wherein:
the shell 1 is a continuous conductor connected to the outer ring of the radio frequency coaxial cable adapter, and the conductor may be a tube, a semicircular tube, a spring, a rod, or a combined conductor formed by connecting a plurality of conductors through a conductive connecting piece. For example: two or more nested conductor tubes, two or more conductor tubes communicating by a metal connection, etc. Fig. 4 illustrates a general cross-sectional view of the housing. Fig. 7 illustrates a common connection mode between different sections of the housing when the housing is formed by a plurality of parts.
The inner rod 2 is also a continuous conductor, and as with the outer shell 1, the inner rod 2 can also be in different geometric shapes, the cross section can be in a circular, rectangular or semicircular shape, and the like, can be a straight rod, can be a curved rod such as a spring, and the like, and can also be a connecting piece for connecting a plurality of conductors together. In special cases, the cavity length measuring device can still measure the needed parameters by demodulating signals through the demodulating device without using an inner rod. Fig. 5 illustrates a cross-sectional view of a common inner rod. Fig. 7 illustrates a common connection mode between inner rods of different sections when the inner rods are formed by a plurality of parts.
The first reflection point 3 and the second reflection point 4 refer to objects within the envelope of the outer shell and the inner rod, and may be in various shapes, different sizes, different materials, or a combination of multiple parts. As long as it can perform a reflecting function. If the reflecting point is a conductor connecting the outer envelope and the inner rod, the reflectivity of this point will be high, and if the reflecting point is not a conductor connecting the outer envelope and the inner rod, the reflectivity will be lower. Fig. 6 is a cross-sectional view showing a typical reflection point, and the shaded portion is the reflection point.
The resonant cavity 5 refers to a resonant cavity between the first reflection point and the second reflection point and between the outer shell and the inner rod, the medium in the resonant cavity is vacuum, gas, liquid or solid, if the medium is solid, the solid cannot be filled in the moving range of the reflection point, and thus the movement of the reflection point cannot be influenced.
The radio frequency coaxial cable adapter 6 is generally an SMA connector or other connectors, the outer ring of the radio frequency coaxial cable adapter 6 is connected with the shell 1, and the central signal needle 7 of the radio frequency coaxial cable adapter is connected with the inner rod 2. In addition, the rf coaxial cable adapter 16 is typically a male or female revolution connector. The interface between the demodulation device and the microwave resonant cavity is not limited to a common SMA joint or a revolution male joint and a revolution female joint, and can also be a radio frequency coaxial cable adapter in other forms.
The vector network analyzer or scalar microwave analyzer, or the circuit 9 for measuring and demodulating the frequency spectrum is a device for measuring the reflection amplitude spectrum or transmission amplitude spectrum of the hollow coaxial cable-fabry-perot resonator. Likewise, 9 also refers broadly to circuitry used to measure and demodulate the spectrum.
The 15 is the end device of the outer shell 1 and the inner rod 2, which can be a conductor, an insulator, a closed or non-closed structure, or a coaxial load or a load resistor of the end of the outer shell and the inner rod.
The load resistor 22 or the coaxial load 23 connected to the end of the outer shell and the inner rod is used for dissipating energy, i.e. eliminating energy which is not reflected back through the second reflection point, so that the end of the sensor does not reflect.
Reference numeral 50 denotes a demodulation system, which is a generic term for instruments that demodulate the cavity length, including all reflection, transmission or loop based demodulation instruments. The demodulation system 50 of various mechanical structure collocation of this patent is in order to simplify under the same mechanical structure, the components and parts connected mode of different principles.
Fig. 1 is a core element of a hollow coaxial cable-fabry-perot resonator, which includes a housing 1, an inner rod 2, a first reflection point 3, a second reflection point 4, and a resonator 5.
Fig. 2(a) and 2(b) show two cases of the fabry-perot resonator without the inner rod and with the inner rod, respectively, where the outer shell and the inner rod may be in various shapes and may be in connection structures of various conductors, and two reflection points are only within the envelope range of the outer shell 1 and the inner rod 2.
Fig. 4 shows a cross-section of a conventional housing 1, which may be a ring, a square frame or various irregular shapes, and which may even be a spring or a round rod. Or may be divided into a combination in which a plurality of conductors are connected together as long as a continuous conductor is satisfied.
Fig. 5 shows a cross-sectional view of a conventional inner rod 2, which may be hollow or solid, and may have various cross-sections, such as circular, rectangular and regular polygonal cross-sections. The inner rod 2 can be a space curve structure such as a spring. The inner rod 2 may also be divided into a combination of a plurality of conductors connected together as long as a continuous conductor is satisfied.
Fig. 6 is a cross-sectional view of a conventional reflection point 3 or 4, which may have various shapes. The reflecting point can be a conductor or an insulator, so long as a part of the reflecting point is within the envelope range of the outer shell 1 and the inner rod 2; the reflection point may or may not be in contact with the outer shell and/or the inner rod. Taking the case that the outer shell 1 is a cylinder and the inner rod is a round rod as an example, the reflection point may be a cylinder or a ring filled between the outer shell 1 and the inner rod 2, or an object covering the gas region between the outer shell 1 and the inner rod 2, such as a small round rod or a porous disc shown in fig. 3, 4 and 5 in fig. 6.
Fig. 7 is a schematic diagram of the connection between the outer shell and the outer shell or the connection between the inner rod and the outer shell after the outer shell 1 or the inner rod 2 is connected in sections. Fig. 7 shows that the common connection modes include overlapping, dislocating, nesting, or connecting by a rotating shaft, and connecting by a conductor corrugated pipe, and in short, when the different sections of the segmented outer shell 1 or inner rod 2 relatively move or rotate, the conductive continuity of the outer shell 1 or inner rod 2 is satisfied.
On this basis, a general configuration of the cavity length measuring apparatus is shown in fig. 8 and 9.
Fig. 8(a) and (b) are schematic structural views of a reflective cavity length measuring apparatus according to an embodiment of the present application. When the inner rod 2 is not provided, the shell 1 is connected with a radio frequency coaxial cable adapter 6. When the inner rod 2 is arranged, the shell 1 and the inner rod 2 are connected with the radio frequency coaxial cable adapter 6. 3 and 4 are respectively a first reflection point and a second reflection point, if the outer shell 1 and the inner rod 2 are connected with the radio frequency coaxial cable adapter 6, the connection part has certain reflectivity, and the connection part can be used as the first reflection point. A vector network analyzer or a scalar microwave analyzer, or a circuit 9 for measuring and demodulating the frequency spectrum, is used to transmit and receive microwave signals to demodulate the length of the resonant cavity 5, i.e. the effective distance between the first reflection point 3 and the second reflection point 4. When coaxial cable is used for transmission, as shown in fig. 8 (a); if the demodulation apparatus is placed directly at the end of the sensor, no coaxial cable transmission is required, as shown in fig. 8 (b).
Fig. 9 is a schematic diagram of a loop structure of a loop based transmission or positive feedback loop. It means that the radio frequency coaxial cable adapter 6 is connected with the outer shell 1 and the inner rod 2 at the left end of the outer shell 1 and the inner rod 2, and the other radio frequency coaxial cable adapter 16 is connected to the wall of the outer shell, not at the right end. When there is no inner rod 2, it is the rf coaxial cable adapter 6 that is connected to the housing 1 at the left end of the housing 1, and the other rf coaxial cable adapter 16 is connected to the wall of the housing, not at the right end. When there are two reflection points 3 and 4, the cavity length between the two reflection points is measured. When there is only one reflection point 4, the loop circumference is measured.
Fig. 9(a) is a schematic diagram of a loop structure of a first transmission or positive feedback loop type cavity length measuring device, in which a demodulating device 9 is connected to a left-end coaxial cable adapter 6 and a radio-frequency coaxial cable adapter 16 on a tube wall through two coaxial cables 8; fig. 9(b) is a schematic diagram of a loop structure of a second transmission or positive feedback loop type cavity length measuring device, in which one end of a demodulating device 9 is welded to a radio frequency coaxial cable adapter 16 connected to the wall of a housing tube, and the other end is connected to a left end coaxial cable adapter 6 by a coaxial cable 8; fig. 9(c) is a schematic diagram of a loop structure of a third transmission or positive feedback loop type cavity length measuring device, in which one end of a demodulation device 9 is welded at the end portions of the outer shell 1 and the inner rod 2, and the other end is connected to a coaxial cable adapter 16 on the tube wall through a coaxial cable 8; fig. 9(d) is a schematic diagram of a loop structure of a fourth transmission or positive feedback loop type cavity length measuring device, in which one end of the demodulating device 9 is welded to the end portions of the outer shell 1 and the inner rod 2, and the other end is welded to a radio frequency coaxial cable adapter 16 connected to the tube wall of the outer shell.
Example two: liquid level sensor
The liquid level sensor comprises the cavity length measuring device of the first embodiment, wherein, in the case of two reflecting points, one reflecting point is a fixed point, and the other reflecting point is a liquid surface or a floating object on the liquid surface (the reflecting point can move), and the cavity length variation of the microwave resonant cavity represents the distance variation of the second reflecting point relative to the first reflecting point, namely the liquid level variation. In the case of only one reflection point, the size of the liquid level amount is found by measuring the perimeter of the positive feedback loop. The liquid level sensor is the basis of an inclinometer, and the inclinometer is formed by combining the liquid level sensor through a plurality of mechanical structures.
1) Level sensor without coaxial cable for transmitting signal
One end of the outer shell 1 and the inner rod 2 of the liquid level sensor is connected with a Printed Circuit Board (PCB) for measuring and demodulating microwave signals, hereinafter referred to as a Circuit Board 9 for short, and the other end of the Circuit Board 9 is a connection terminal which can transmit measured frequency spectrum, resonant cavity length and other required information through wires or wirelessly.
Fig. 9(d) is a schematic diagram of the level sensor of the present application without the coaxial cable 8 transmitting a signal. The distance between the two reflection points 3 and 4 is the cavity length of the resonant cavity 5 (namely, the resonant cavity length), in general, one of the two reflection points is a fixed point, which can be a fixed reflection point added at a certain position on the sensor, or the end parts of the outer shell 1 and the inner rod 2, and the other reflection point is the liquid level, so that after the liquid level changes, the distance between the two reflection points changes, and the variation of the liquid level can be obtained by measuring the variation of the distance between the two reflection points. The obtained signal is subjected to spectrum analysis directly by a demodulation device such as a demodulation circuit. The ends of the outer shell and the inner rod can be sealed, and can also be connected with a load resistor or a coaxial load so as to eliminate reflection of the ends.
2) Several structures of liquid level sensor
Because the reflectivity of different liquid levels is different, if the reflectivity is lower, the end parts of the outer shell and the inner rod can form high reflection, and the signal and the precision are influenced. The end of the outer shell and the inner rod therefore need to be considered for energy dissipation. Typically, the reflectivity of the conductive liquid is high and the reflectivity of the insulating liquid is low.
Fig. 10(a) is an overall structure of a liquid level sensor of an embodiment of the present application, including two reflection points 3 and 4, and a demodulation system 50. The end parts 15 of the outer shell 1 and the inner rod 2 can be conductors or insulators, can be closed or non-closed structures, and can be coaxial loads or load resistors serving as ends.
FIG. 10(b) is a structural view of a liquid level sensor in which the liquid level is the second reflection point. The liquid level acts as a second reflection point 4, the ends of the housing 1 and the inner rod 2 being open. In general, in this case, the reflectance of the liquid surface is high, and the end portion is not easily highly reflective, so that the end portion may be of an open structure.
Fig. 10(c) is a structural view of a liquid level sensor in which a liquid level float is used as a second reflection point. The liquid level float acts as a second reflection point 4, the ends of the outer shell 1 and the inner rod 2 being open. In general, in this case, the reflectivity of the float is high, and the end portion is not easily reflected, so that the end portion may be of an open structure.
Fig. 10(d) is a schematic diagram of a sensor structure in which the coaxial loads are connected to the ends of the outer shell and the inner rod. The ends of the outer shell 1 and the inner rod 2 are connected with coaxial loads. Generally, under the condition, the total reflectivity of two reflecting points is still not high and cannot reach total reflection, if the end parts are open, high reflection is easily formed, and the signal and the precision are influenced, so that the end parts of the shell 1 and the inner rod 2 are connected with coaxial loads for dissipating energy, the end part reflection is reduced, the precision of the sensor is improved, and the end surfaces of the shell and the inner rod where the coaxial loads are located can be sealed or not sealed.
Fig. 10(e) is a structural view of the liquid level sensor in which the liquid level is the second reflection point and the end is connected with the coaxial load. The liquid level is used as a second reflection point 4, and the ends of the outer shell 1 and the inner rod 2 are connected with coaxial loads. Generally, the total reflectivity of the first reflection point and the liquid level (second reflection point) is low, if the end part is open, high reflection is easily formed, and the signal and precision are influenced, so that the end parts of the shell 1 and the inner rod 2 are connected with coaxial loads to dissipate energy, the end part reflection is reduced, and the precision of the sensor is improved.
Fig. 10(f) is a schematic diagram of a sensor structure in which the ends of the outer casing and the inner rod are connected with load resistors. The rest is the same as fig. 10(d), except that the coaxial load at the end is replaced by a load resistor, and the effect is the same as that of connecting the coaxial load, all for eliminating the reflection at the end.
FIG. 10(g) is a structural view of a level sensor in which the liquid surface is the second reflection point and the end is connected with a load resistor. The rest is the same as fig. 10(e), except that the coaxial load at the end is replaced by a load resistor, and the effect is the same as that of connecting the coaxial load, all for eliminating the reflection at the end.
Example three: structural principle of one-way inclinometer
The difference between an inclinometer and a level sensor is that one of its reflection points is changed into a point which can be moved relative to a fixed reflection point under the influence of inclination. Typically the liquid level acts as a moving reflection point. The inclination angle is measured by utilizing the characteristic that the position of the liquid level moves relative to the fixed reflection point after the liquid level is inclined. Preferably, two liquid level sensors are used for making difference, so that the influence of factors such as thermal expansion generated by temperature can be eliminated. The demodulation system may employ a reflective, transmissive or loop configuration.
1) Inclinometer of single liquid level sensor
As shown in fig. 11, a U-shaped tube 40 is connected to the end of the liquid level sensor housing 1, the liquid 31 is filled in the tube, the liquid is immersed in the ends of the liquid level sensor housing 1 and the inner rod 2, and a vent tube 32 is connected between the U-shaped tube 40 and the gas area of the liquid level sensor, so that the gas pressure difference can be eliminated. An inclinometer composed of a liquid level sensor and a U-shaped tube 40 is fixed to an object to be measured, and a point above the liquid level serves as a first reflection point 3 and the liquid level serves as a second reflection point 4. When the inclination angle changes on a plane formed by the liquid level sensor and the axis of the U-shaped pipe, the liquid level in the liquid level sensor changes, namely the length of a resonant cavity between the first reflection point 3 and the second reflection point 4 changes, and meanwhile, the included angle between the liquid level (the second reflection point 4) and the axis of the liquid level sensor also changes. The size of the inclination angle can be determined by measuring the variation of the resonant cavity length under different inclination angles and then performing temperature compensation. When the reflectivity of the liquid surface of the liquid 31 is low, the load resistor 22 or the coaxial load 23 is adopted at the end part of the liquid level sensor shell and the inner rod for energy dissipation.
2) Inclinometer with two liquid level sensors rotating along with object to be measured
As shown in fig. 12, two liquid level sensors are used as a unidirectional inclinometer which does not need temperature compensation and rotates along with the measured object, when the outer shell and the inner rod end of the liquid level sensor have no energy dissipation system or adopt load resistance or load resistance to dissipate energy:
as shown in fig. 12(a), two parallel liquid level sensors are vertically arranged, the demodulation device is arranged at the top, the liquid areas in the two liquid level sensors need to be communicated, a U-shaped pipe 40 is used for communicating at the bottoms of the two liquid level sensors in the figure, the end parts of the two liquid level sensors can be connected to the same container, or the liquid areas of the two liquid level sensors are communicated by a pipe. In short, it is sufficient to connect the two liquid level sensor liquid areas, which are collectively referred to as the communicating vessel 40. The end parts of the outer shell 1 and the inner rod 2 of the two liquid level sensors are immersed in the liquid 31, and the liquid 31 is also in the communicating container 40, namely the liquid areas in the two liquid level sensors are communicated; a vent pipe 32 is communicated between the gas areas above the liquid levels of the two liquid level sensors, so that the pressure difference inside the shells of the two liquid level sensors can be eliminated. The inclinometer composed of a liquid level sensor and a communicating container is fixed on a measured object, the two liquid level sensors, a fixed point 3 in a gas area above the liquid level is used as a first reflecting point, and the liquid level is used as a second reflecting point 4.
Fixing the whole system on the measured object, wherein the initial cavity length of the two liquid level sensors is L1And L2The parallel spacing of the axes is d. When the inclination angle changes on a plane formed by the axes of the two liquid level sensors, the liquid levels in the two liquid level sensors change, namely the length of a resonant cavity between a first reflection point and a second reflection point of the two liquid level sensors changes, and the change amounts are respectively delta L1And Δ L2Difference DeltaL of resonant cavity length variation by two liquid level sensors2-ΔL1And the size of the parallel distance d, the tilt angle change amount Δ θ ═ arctan [ (Δ L)2-ΔL1)/d]. Because the two liquid level sensors are made of the same material and have the same liquid inside, the influence of temperature on the cavity length is eliminated when the cavity length change amount is subjected to difference, and temperature compensation is not needed.
As shown in fig. 12(b), when the reflectivity of the liquid surface is low, in order to prevent the end portions of the outer shell 1 and the inner rod 2 from forming high reflection to affect the signal and the accuracy, the end portions of the outer shell and the inner rod are energy-dissipated by using the load resistor 22, so that the end reflection is greatly reduced. The inclination angle is calculated in the same manner as in the case of fig. 12 (a).
As shown in fig. 12(c), when the reflectivity of the liquid surface is low, in order to prevent the end portions of the outer shell 1 and the inner rod 2 from forming high reflection to affect the signal and the accuracy, the coaxial load 23 can be used for energy dissipation, so that the end reflection is greatly reduced. At this time, the inside of the housing 1 of a length of the level sensor near the coaxial load 23 serves as a container for containing liquid. The fixed first reflection point is above the liquid, the liquid is above the coaxial load, and the liquid level is used as the second reflection point. The liquid areas inside the two level sensors are communicated by a communicating vessel 40, and the liquid 31 is also in the communicating vessel, namely the liquid areas inside the two level sensors are communicated; and a vent pipe 32 is communicated with the gas area above the liquid level of the two liquid level sensors, so that the gas pressure difference can be eliminated. An inclinometer composed of a liquid level sensor and a communicating container is fixed to an object to be measured. The inclination angle is calculated in the same manner as in the case of fig. 12 (a).
As shown in fig. 12(d), when the reflectivity of the liquid surface is low and the first end of the level sensor and the demodulator are placed at the bottom, a vent tube 32 is used to communicate between the top of the two level sensors. The level sensor places a sealing plug 39 close to the detuning means, ensuring that the liquid is above the sealing plug. At this time, the top of the sealing plug 39 or the bottom surface of the liquid serves as the first reflection point 3; the top surface of the liquid is also always lower than the top of the outer shell and the inner rod, and the liquid level is used as a second reflection point 4 of the two liquid level sensors. Openings are formed in the housing wall corresponding to the liquid areas inside the two level sensors, and a communicating vessel 40 is used for communicating the liquid areas inside the two level sensors, wherein the communicating vessel also contains the same liquid, namely the liquid areas inside the two level sensors are communicated. Because the upper and lower surfaces of the liquid are selected as two reflecting points, the selected liquid has certain transmissivity and certain reflectivity. The ends of the outer shell and the inner rod are typically energy-dissipating using coaxial loads or load resistors. The inclination angle is calculated in the same manner as in the case of fig. 12 (a).
3) Inclinometer enabling two liquid level sensors to be always kept in vertical state based on rotating shaft and weight
Two liquid level sensors are used as a one-way inclinometer which does not need temperature compensation and does not rotate along with a measured object, the two liquid level sensors are fixed by a rotating shaft, a heavy hammer is arranged below the liquid level sensors, the axis of the liquid level sensors is vertical all the time no matter how the inclination angle changes, and the structural schematic diagram is shown in figure 13. When the shell and the end part of the inner rod of the liquid level sensor have no energy dissipation system or adopt a load resistor to dissipate energy:
as shown in fig. 13(a), two liquid level sensors are used as a kind of unidirectional inclinometer without temperature compensation, and the axis of the liquid level sensor is vertical all the time, i.e. when the inclination angle changes, the liquid level sensor does not rotate, specifically:
when the total reflectivity of the first reflection point 3 and the second reflection point 4 (liquid level) is low, the liquid areas inside the outer shell and the inner rod are communicated through a hose, and no space is connected with a coaxial load 23, so the end parts of the outer shell 1 and the inner rod 2 of the liquid level sensor adopt a load resistor 22 for energy dissipation.
With two parallel level sensors, the detuning system 50 is on top, the two level sensors are each fixed to the base plate 35 by a rotating shaft 33, i.e. the level sensors can rotate around the rotating shaft 33, but cannot move. The rotation axis 33 is typically below the second reflection point 4 of the level sensor, i.e. below the liquid level 4, and the connection line of the rotation axes 33 of the two level sensors is perpendicular to the axes of the two level sensors, i.e. the two rotation axes are equal in height. The weight 38 is added to the bottom of each liquid level sensor to ensure that the axis of the liquid level sensor is always vertical no matter how the substrate is driven to rotate after the inclination angle changes. The two level sensors are again connected at their bottoms by a hose 34, which can be protected by a housing 41, which is fixed to the two pivot points 33. The end parts of the two liquid level sensor shells 1 and the inner rod 2 are immersed in the liquid 31, and the liquid is also contained in the hose 33, namely the liquid areas in the two liquid level sensors are communicated; an air hose 36 is communicated between the two liquid level meters, so that air pressure difference can be eliminated, and the liquid level sensor cannot be driven to rotate. Two level sensors, a fixed point in the gas region above the liquid surface as a first reflection point 3 and the liquid surface as a second reflection point 4.
In order to avoid resistance brought by a hose for communicating liquid with a gas area, or the whole system is placed into a closed container, liquid is filled at the bottom of the closed container, one part of a shell and an inner rod of the two liquid level sensors is always immersed into the liquid at the bottom of the closed container, the liquid areas inside the two liquid level sensors are communicated with the liquid at the bottom of the closed container, and the gas areas of the two liquid level sensors are communicated with the gas above the liquid level of the closed container, so that the pressure difference between the gas areas above the liquid level inside the two liquid level sensors is eliminated.
The whole base plate 35 is fixed on the measured object, and the initial cavity length of the two liquid level sensors is L1And L2And the distance L between the two rotating shafts. When the inclination angle changes on a plane formed by the axes of the two liquid level sensors, the axes of the two liquid level sensors are vertical all the time, the liquid level in the liquid level sensors can change, the liquid level is perpendicular to the axes of the liquid level sensors all the time, namely, the length of a resonant cavity between a first reflection point and a second reflection point of the two liquid level sensors changes, and the change amounts are respectively delta L1And Δ L2Difference DeltaL of resonant cavity length variation by two liquid level sensors2-ΔL1And the distance L between the two rotating shafts on the substrate, namely the variation quantity delta theta of the inclination angle is arcsin [ (delta L)2-ΔL1)/L]. Because the two liquid level sensors are made of the same material and have the same liquid inside, the influence of temperature on the cavity length is eliminated when the cavity length change amount is subjected to difference, and temperature compensation is not needed.
As shown in fig. 13(b), two liquid level sensors are used as a kind of unidirectional inclinometer without temperature compensation, and the axis of the liquid level sensor is vertical all the time, i.e. when the inclination angle changes, the liquid level sensor does not rotate, specifically:
when the liquid level 4 is less reflective, the coaxial loads 23 are used to dissipate and seal at the bottom of the two level sensors, i.e. the ends of the housing and the inner rod. At this time, a length of the level sensor near the coaxial load serves as a container for containing the liquid.
With two parallel level sensors placed vertically, the detuning system 50 at the top, and at the bottom of the two level sensors, i.e. the ends of the housing and the inner rod, the coaxial load 23 is used for energy dissipation and sealing treatment there. At this time, a length of the level sensor near the coaxial load 23 serves as a container for containing the liquid. The fixed first reflection point 3 is above the liquid, which is above the coaxial load 23, and the liquid surface is the second reflection point 4. The two level sensors are each fixed to a base plate 35 by a pivot 33, i.e. the level sensors can be pivoted about the pivot, but cannot be moved. The rotating shaft 33 can be at any point on the axes of the liquid level sensors, the rotating shaft 33 can be placed at the intersection point of the axes of the liquid region communication hose 36 and the axes of the liquid level sensors, and the connecting line of the rotating shafts 33 of the two liquid level sensors is perpendicular to the axes of the two liquid level sensors, namely, the two rotating shafts are equal in height. The weight 38 is added to the bottom of each liquid level sensor to ensure that the axis of the liquid level sensor is always vertical no matter how the substrate is driven to rotate after the inclination angle changes. The liquid area between the two liquid level sensors is communicated by a hose 36, and the liquid is also in the hose 36, namely the liquid areas in the two liquid level sensors are communicated, and the rigidity of the hose is as small as possible. And a soft vent pipe 36 is communicated with a gas area above the liquid level of the two liquid level sensors, so that the gas pressure difference can be eliminated, and the rigidity of the soft pipe 36 is also as small as possible. The inclination angle is calculated in the same manner as in the case of fig. 13 (a).
4) Clinometer for enabling two liquid level sensors to always keep vertical state based on flexible lifting rope
The two liquid level sensors are used as a one-way inclinometer which does not need temperature compensation and does not rotate along with a measured object, the two liquid level sensors are lifted by adopting a flexible rope, the axis of the liquid level sensors is vertical all the time no matter how the inclination angle changes, and the structural schematic diagram is shown in figure 14. When the shell and the end part of the inner rod of the liquid level sensor have no energy dissipation system or adopt a load resistor to dissipate energy:
as shown in fig. 14(a), two liquid level sensors are used as a kind of unidirectional inclinometer without temperature compensation, and the axis of the liquid level sensor is vertical all the time, i.e. when the inclination angle changes, the liquid level sensor does not rotate, specifically:
when the liquid level reflectivity is low, the inner part of the shell is communicated with the liquid in the container at the bottom opening of the shell, and no space is connected with a coaxial load 23, so the energy dissipation of the shell of the liquid level sensor and the end part of the inner rod is realized by adopting a load resistor 22.
A closed container 30 is adopted, two flexible ropes 43 are fixed on the top plate of the container, a liquid level sensor is hung below each flexible rope, wherein a demodulation system 50 of the liquid level sensor is arranged at the top of the sensor and hung below the flexible ropes 43, the gravity center of the whole liquid level sensor is coincided with the axis, and the gravity center of the whole liquid level sensor is arranged on the extension line of the flexible ropes 43. This ensures that the axis of the suspended level sensor is vertical. Each liquid level sensor can also be fixed to the top plate through a group of flexible ropes with equal length, namely the number of the flexible ropes corresponding to each liquid level sensor is more than or equal to two, so that the liquid level sensors can be prevented from rotating around the axis. These equal length flexible cords are generally placed in parallel and vertically. A certain amount of liquid 31 is put into the closed container, so that the two liquid level sensors are ensured to have a section of the shell 1 and the inner rod 2 which are immersed in the liquid 31 all the time, and the liquid of the two liquid level sensors also naturally keeps connectivity. A vent hole 32 is formed in the gas area of each liquid level sensor, so that the gas area of each liquid level sensor is communicated with the gas area without liquid in the closed container, and the gas pressure difference can be eliminated. Two level sensors, a fixed point in the gas region above the liquid surface as a first reflection point 3 and the liquid surface as a second reflection point 4.
The entire container 30 is fixed to the object to be measured, and the initial chamber length of the two liquid level sensors is L1And L2And the distance L between the two rotating shafts. When the inclination angle changes on the plane formed by the axes of the two liquid level sensors, the axes of the two liquid level sensors are vertical all the time, the liquid level in the liquid level sensors changes, the liquid level 4 is perpendicular to the axes of the liquid level sensors all the time, namely, the length of a resonant cavity between a first reflection point and a second reflection point of the two liquid level sensors changes, and the change amounts are respectively delta L1And Δ L2Difference DeltaL of resonant cavity length variation by two liquid level sensors2-ΔL1And the distance L between the two flexible ropes and the fixed points on the top plate can obtain the inclination angle variation delta theta (arctan [ (delta L)2-ΔL1)/L]. Because the two liquid level sensors are made of the same material and have the same liquid inside, the influence of temperature on the cavity length is eliminated when the cavity length change amount is subjected to difference, and temperature compensation is not needed.
At this time, if the flexible string 43 of fig. 14(a) is replaced with a rigid rod, that is, two liquid level sensors are fixedly connected to the top of the closed container, any position of the liquid level sensor may be fixedly connected to the top, bottom, or side surface of the closed container, as long as the function of fixing the liquid level sensor and facilitating the sealing is achieved. The mechanism and calculation formula of the inclinometer are the same as those in fig. 12(b) except that the container is replaced by one, two liquid level sensors are arranged in the closed container, and liquid is only arranged at the bottom in the container.
As shown in fig. 14(b), two liquid level sensors are used as a kind of unidirectional inclinometer without temperature compensation, and the axis of the liquid level sensor is vertical all the time, i.e. when the inclination angle changes, the liquid level sensor does not rotate, specifically:
when the liquid level reflectivity is low, the coaxial loads 23 are used to dissipate energy and seal at the bottom of the two level sensors, i.e. the ends of the housing 1 and the inner rod 2. At this time, a length of the level sensor near the coaxial load serves as a container for containing the liquid.
A closed container is adopted, and the top plate of the container is fixed. Two flexible ropes 43, one level sensor is hung below each flexible rope, wherein the demodulation system 50 of the level sensor is arranged at the top of the sensor and hung below the flexible ropes 43, and the gravity center of the whole level sensor is coincided with the axis and is arranged on the extension line of the flexible ropes 43. This ensures that the axis 43 of the suspended level sensor is vertical. Each liquid level sensor can also be fixed to the top plate through a group of flexible ropes with equal length, namely the number of the flexible ropes corresponding to each liquid level sensor is more than or equal to two, so that the liquid level sensors can be prevented from rotating around the axis. These equal length flexible cords are generally placed in parallel and vertically. A certain amount of liquid 31 is put into the closed container, so that a section of shell and an inner rod of the two liquid level sensors are always immersed in the liquid 31, the bottoms of the two liquid level sensors are provided with coaxial loads 23 or sealing parts, so that openings 42 are needed to be respectively arranged at the positions, close to the bottoms of the shells, of the two liquid level sensors, the two openings 42 are always immersed in the liquid, the connectivity between the liquid inside the shells of the two liquid level sensors and the liquid outside the shells is ensured, and the connectivity of the liquid of the two liquid level sensors is naturally maintained. A vent hole 32 is formed in the gas area of each liquid level sensor, so that the gas area of each liquid level sensor is communicated with the gas area without liquid in the closed container, and the gas pressure difference can be eliminated. Two level sensors, a fixed point in the gas region above the liquid surface as a first reflection point 3 and the liquid surface as a second reflection point 4. The inclination angle is calculated in the same manner as in the case of fig. 14 (a).
At this time, if the flexible string 43 in fig. 14(b) is replaced with a rigid rod, that is, two liquid level sensors are fixedly connected to the top of the closed container, any position of the liquid level sensor may be fixedly connected to the top, bottom, or side surface in the closed container, as long as the function of fixing the liquid level sensor and facilitating the sealing is achieved. The mechanism and calculation formula of the inclinometer are the same as those in fig. 12(c), except that the container is replaced by one, two liquid level sensors are arranged in the closed container, and only the bottom of the container is filled with liquid.
Example four: structural principle of double inclinometers
The difference between the bidirectional inclinometer and the unidirectional inclinometer is that three or more liquid level sensors are adopted, and all intersection points of the axes of all the liquid level sensors and the horizontal plane are not on the same straight line.
1) Inclinometer with three liquid level sensors rotating along with object to be measured
As shown in fig. 15, three level sensors are used as a bidirectional inclinometer which does not need temperature compensation and rotates along with the measured object, and the shell and the end part of the inner rod of the level sensor or an energy dissipation free system; or energy dissipation by using a load resistor, as shown in FIG. 15 (a); or coaxial load energy dissipation is adopted, as shown in fig. 15(b), the liquid level measurement mechanism is the same as that of the method in fig. 12 in the working condition two of the embodiment 3, namely the method in which two liquid level sensors rotate along with a measured object, and the difference is that three or more liquid level sensors are adopted to realize the measurement of bidirectional inclination:
three liquid level sensors 61, 62 and 63 are adopted, and when the three liquid level sensors are vertically arranged, the two-way inclination can be measured as long as three points projected on a horizontal plane are not on the same straight line. Fixing the inclinometer on a measured object, wherein first reflection points of the three liquid level sensors are all positioned above second reflection points; the initial cavity lengths of the three liquid level sensors are respectively L1、L2And L3When three intersection points of the axes of the three liquid level sensors and the horizontal plane form a right-angled triangle, the two right-angled sides are respectively an X axis and a Y axis in the inclined direction; the first liquid level sensing axis and the second liquid level sensing axis are parallel at a distance d1The parallel distance between the axes of the second level sensor and the third level sensor is d2(ii) a Preferably, when three intersection points of the axes of the three liquid level sensors and the horizontal plane form an isosceles right triangle, d1＝d2。
In fig. 15(a), the bottoms of the three liquid level sensors are connected to a communicating vessel 30, that is, the cavities of the three liquid level sensors and the communicating vessel are communicated, and the liquids in the three liquid level sensors are communicated. The container and parts of the housing and the inner rod of the three level sensors are always immersed in the liquid 31. A vent pipe 32 is respectively communicated between the first liquid level sensor and the second liquid level sensor, the communicated area is positioned above the liquid level (the second reflection point 4), and the gas area areas in the three liquid level sensors are also communicated, so that the gas pressure difference in the gas area areas among the three liquid level sensors can be eliminated.
In fig. 15(b), the interior of the housing 1, which is a length of the level sensor near the coaxial load 23, serves as a container for holding liquid. The fixed first reflection point is above the liquid, the liquid is above the coaxial load, and the liquid level is used as the second reflection point. The first liquid level sensor and the third liquid level sensor are respectively communicated with the second liquid level sensor by a communicating container 40, and the liquid 31 is also in the communicating container, namely liquid areas in the three liquid level sensors are communicated; in the gas area above the liquid level of the three liquid level sensors, a vent pipe is respectively communicated between the first liquid level sensor and the third liquid level sensor and the second liquid level sensor, so that the air pressure difference can be eliminated. An inclinometer composed of a liquid level sensor and a communicating container is fixed to an object to be measured.
The three liquid level sensors are fixed on a measured object by an inclinometer consisting of three liquid level sensors and a communicating container, wherein a fixed point in a gas area above the liquid level is used as a first reflecting point 3, and the liquid level is used as a second reflecting point 4.
Fixing the whole system on the object to be measured, wherein the initial cavity length of the three liquid level sensors is L1、L2And L3When the three intersection points of the axes of the three liquid level sensors and the horizontal plane form an isosceles right triangle, the overlooking view is as shown in fig. 16(a), and the two right-angled sides are the X and Y rotating shafts in the tilting direction respectively. In this case, the calculation method shown in FIGS. 15(a) and (b) is such that the first level sensor and the second level sensor have their axes parallel to each other at a distance d1The parallel distance between the axes of the second level sensor and the third level sensor is d2. When the inclinometer inclines around the X axis and the Y axis, the signs are judged according to the right-hand criterion. The cavity length between the first reflection point and the second reflection point of the first level sensor 61 and the second level sensor 62 changes by Δ L1And Δ L2Difference DeltaL of resonant cavity length variation by two liquid level sensors2-ΔL1And a parallel spacing d1By the amount of (2), the amount of change in the tilt angle [ Delta ] [ theta ] of the inclinometer about the X axis can be obtained1＝arctan[(ΔL2-ΔL1)/d1]. The cavity length between the first reflection point and the second reflection point of the second level sensor 62 and the third level sensor 63 also changes by Δ L2And Δ L3Difference DeltaL of resonant cavity length variation by two liquid level sensors3-ΔL2Peace and quietLine spacing d2By the magnitude of (1), the change amount Delta theta of the inclination angle of the inclinometer around the Y axis can be obtained2＝arctan[(ΔL3-ΔL2)/d2]. Preferably, when three intersection points of the axes of the three liquid level sensors and the horizontal plane form an isosceles right triangle, d1＝d2。
2) Clinometer for enabling two liquid level sensors to always keep vertical state based on flexible lifting rope
As shown in fig. 17, three level sensors are fixed to the top plate by a flexible rope, and the outer shell and the end of the inner rod of the level sensor or the energy dissipation system is absent; or energy dissipation by adopting load resistance, as shown in figure 17 (a); or coaxial load energy dissipation is adopted, as shown in figure 17(b), the liquid level measurement mechanism is the same as that of the method in figure 14(a) and figure 14(b) in the working condition four 'inclinometer based on flexible lifting ropes and enabling two liquid level sensors to be always kept in a vertical state' of the working condition four in the embodiment 3, and the difference is that three or more liquid level sensors are adopted to realize the measurement of bidirectional inclination. Similarly, each liquid level sensor can be fixed to the top plate by a group of flexible ropes with equal length, namely the number of the flexible ropes corresponding to each liquid level sensor is more than or equal to two, so that the liquid level sensors can be prevented from rotating around the axis. These equal length flexible cords are generally placed in parallel and vertically.
In figure 17(a), based on energy-free or load-resistance energy-dissipating structure, a closed container 30 is used, three flexible ropes 43 are fixed on the top plate of the container, a liquid level sensor is suspended below each flexible rope, wherein a demodulation system 50 of the liquid level sensor is arranged on the top of the sensor and is suspended below the flexible ropes 43, the gravity center of the whole liquid level sensor is coincident with the axis, and is arranged on the extension line of the flexible ropes 43. This ensures that the axis of the suspended level sensor is vertical. A certain amount of liquid 31 is put into the external closed container, so that the three liquid level sensors 61, 62 and 63 are ensured to have a section of the shell 1 and the inner rod 2 which are immersed in the liquid all the time, and the liquid of the three liquid level sensors also naturally keeps connectivity. A vent hole 32 is formed in the gas area of each liquid level sensor, so that the gas area of each liquid level sensor is communicated with the gas area without liquid in the closed container, and the gas pressure difference can be eliminated. Three level sensors, a fixed point in the gas region above the liquid level as a first reflection point 3 and the liquid level as a second reflection point 4. The tilt angle is calculated in the same manner as for the condition of fig. 15.
In figure 17(b), based on energy-free or coaxial load-dissipating structure, a closed container is used, three flexible ropes 43 are fixed on the top plate of the container, a liquid level sensor is suspended below each flexible rope, wherein a demodulation system 50 of the liquid level sensor is arranged on the top of the sensor and is suspended below the flexible ropes 43, the gravity center of the whole liquid level sensor is coincident with the axial line, and is arranged on the extension line of the flexible ropes 43. This ensures that the axis 43 of the suspended level sensor is vertical. A certain amount of liquid 31 is put into the outer closed container, so that a section of outer shell and an inner rod of the three liquid level sensors 61, 62 and 63 are always ensured to be immersed into the liquid 31, the positions of the three liquid level sensors close to the bottom of the outer shell are respectively provided with an opening 42 because the bottoms of the three liquid level sensors use coaxial loads 23 or sealing parts, the three openings 42 are always immersed into the liquid, the connectivity of the liquid inside the outer shell of the three liquid level sensors and the external liquid is ensured, and the connectivity of the liquid of the three liquid level sensors is naturally maintained. A vent hole 32 is formed in the gas area of each liquid level sensor, so that the gas area of each liquid level sensor is communicated with the gas area without liquid in the closed container, and the gas pressure difference can be eliminated. Three level sensors, a fixed point in the gas region above the liquid level as a first reflection point 3 and the liquid level as a second reflection point 4. The tilt angle is calculated in the same manner as for the condition of fig. 15. For the conditions of fig. 17(a) and (b), the liquid level sensors are shown in fig. 16(a) as a low overhead view, and the lengths of the resonant cavities between the first reflection points and the second reflection points of the first liquid level sensor 61 and the second liquid level sensor 62 are changed by Δ L1And Δ L2Difference DeltaL of resonant cavity length variation by two liquid level sensors2-ΔL1And a parallel spacing d1By the amount of (2), the amount of change in the tilt angle [ Delta ] [ theta ] of the inclinometer about the X axis can be obtained1＝arcsin[(ΔL2-ΔL1)/d1]. Second level sensorThe cavity length between the first reflection point and the second reflection point of the third level sensor 62 and 63 also changes by an amount deltal, respectively2And Δ L3Difference DeltaL of resonant cavity length variation by two liquid level sensors3-ΔL2And a parallel spacing d2By the magnitude of (1), the change amount Delta theta of the inclination angle of the inclinometer around the Y axis can be obtained2＝arcsin[(ΔL3-ΔL2)/d2]. Preferably, when three intersection points of the axes of the three liquid level sensors and the horizontal plane form an isosceles right triangle, d1＝d2。
At this time, if the flexible string 43 of fig. 17(a) and (b) is replaced with a rigid rod, that is, the three level sensors are fixedly connected to the top of the closed vessel, any position of the level sensor may be fixedly connected to the top, bottom, or side surface in the closed vessel, as long as the function of fixing the level sensor and facilitating the sealing is performed. The mechanism of the inclinometer is the same as that of fig. 15, except that the container is replaced by a type, three level sensors are placed inside the closed container, and only the bottom of the container is filled with liquid. The calculation method is the same as the conditions in fig. 15(a) and (b). The variation delta theta of the inclination angle of the inclinometer around the X axis can be obtained1＝arctan[(ΔL2-ΔL1)/d1]The variation delta theta of the inclination angle of the inclinometer around the Y axis can be obtained2＝arctan[(ΔL3-ΔL2)/d2]. Preferably, when three intersection points of the axes of the three liquid level sensors and the horizontal plane form an isosceles right triangle, d1＝d2。
3) Inclinometer with 3 or more liquid level sensors rotating along with measured object
For the bidirectional inclinometer, as long as the number of the liquid level sensors is not less than three and all intersection points of the axes of the liquid level sensors and the horizontal plane are not on the same straight line, the inclination in two directions can be measured. The inclination angle values of the rotating shafts X and Y can be obtained by calculation, and the conversion matrix used for calculation is related to the X and Y values of the coordinates of the axes of the liquid level sensors at the intersection point of the horizontal planes and is also related to which liquid level sensor is selected for calculation. In general, three intersection points of the axes of the three liquid level sensors and the horizontal plane form an isosceles right triangle, and two right-angle sides are the X and Y rotating shafts in the inclined direction respectively, as shown in fig. 16 (a).
Further, four level sensors may be used, and as shown in fig. 16(b), the level difference of the level sensors 61 and 62 and the distance between the axes thereof determine X as the inclination amount of the rotation shaft; the difference in the liquid levels of the liquid level sensors 63 and 64 and the distance between the axes thereof determine Y as the amount of inclination of the rotary shaft. Of course, more than 4 level sensors may be used to measure the bi-directional tilt value, mainly ensuring that all the intersections of the axes of the several level sensors with the horizontal plane are not in a straight line.
The technical means described in the embodiments of the present application may be arbitrarily combined without conflict.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application.

Claims (25)

1. An inclinometer, characterized in that it comprises: at least one liquid level sensor; the main body of each liquid level sensor comprises a liquid area and a gas area, the gas area is positioned above the liquid area, the liquid area in the main body of each liquid level sensor is communicated, and the gas area in the main body of each liquid level sensor is communicated; wherein the content of the first and second substances,
the liquid level sensor comprises a first reflection point and a second reflection point, the position of the first reflection point is fixed, the liquid level of the liquid region or floating objects on the liquid level are used as the second reflection point, and the distance between the first reflection point and the second reflection point is the length of the resonant cavity;
alternatively, the first and second electrodes may be,
the liquid level sensor comprises a positive feedback loop, the positive feedback loop comprises a first reflection point and a second reflection point, the position of the first reflection point is fixed, the liquid level of the liquid area or a floater on the liquid level is used as the second reflection point, and the distance between the first reflection point and the second reflection point is the length of the resonant cavity; alternatively, the positive feedback loop comprises only one reflection point, the liquid level of the liquid region or a float on the liquid level being the reflection point.
2. The inclinometer of claim 1, wherein, with the level sensor comprising the first reflection point and the second reflection point:
the first reflection point is fixed at any position in the envelope range of the outer shell and the inner rod of the liquid level sensor; alternatively, the first and second electrodes may be,
and taking the joint of the radio frequency coaxial cable adapter in the liquid level sensor, the shell and the inner rod as the first reflection point.
3. The inclinometer of claim 1, wherein the level sensor comprises a cavity length measuring device comprising: a microwave resonant cavity and a demodulation device; wherein the content of the first and second substances,
the microwave resonant cavity comprises a hollow coaxial cable-Fabry-Perot resonant cavity and a reflection point positioned inside the hollow coaxial cable-Fabry-Perot resonant cavity;
the first end of the hollow coaxial cable-Fabry-Perot resonant cavity is connected to a radio frequency coaxial cable adapter, and the radio frequency coaxial cable adapter is connected to the demodulation device through a coaxial cable; or the first end of the hollow coaxial cable-Fabry-Perot resonant cavity is connected to a circuit board as a demodulation device.
4. The inclinometer of claim 3,
when the total reflectivity of the reflection points inside the hollow coaxial cable-Fabry-Perot resonant cavity is greater than or equal to a threshold value, the second end of the hollow coaxial cable-Fabry-Perot resonant cavity has no energy dissipation system, or a load resistor or a coaxial load for energy dissipation is connected between the outer shell and the inner rod of the second end of the hollow coaxial cable-Fabry-Perot resonant cavity;
and when the total reflectivity of the reflection point in the hollow coaxial cable-Fabry-Perot resonant cavity is smaller than a threshold value, a load resistor or a coaxial load for energy dissipation is connected between the outer shell and the inner rod of the second end of the hollow coaxial cable-Fabry-Perot resonant cavity.
5. The inclinometer of claim 3, wherein the cavity length measuring device is a reflective cavity length measuring device, or a transmissive cavity length measuring device, or a positive feedback loop cavity length measuring device;
correspondingly, the liquid level sensor is a reflection type liquid level sensor, or a transmission type liquid level sensor, or a positive feedback loop type liquid level sensor; when the liquid level sensor is a transmission type liquid level sensor or a positive feedback loop type liquid level sensor, the liquid level sensor at least has the following modes: loop-free mode, positive feedback loop mode; wherein the content of the first and second substances,
the loop-free mode means that the level sensor is transmissive, not including a positive feedback loop;
the positive feedback loop mode means that the level sensor comprises a positive feedback loop.
6. The inclinometer of claim 5, wherein when the liquid level sensor comprises the positive feedback loop, the positive feedback loop employs a loop with two reflection points, or a loop with one reflection point; wherein the content of the first and second substances,
when the positive feedback loop has two reflection points, the positive feedback loop comprises the first reflection point and the second reflection point, the distance between the first reflection point and the second reflection point is the length of the resonant cavity, and the demodulation device is used for measuring the length of the resonant cavity of the positive feedback loop;
when the positive feedback loop has only one reflection point, the liquid level or the floating object on the liquid level is used as the reflection point, and the demodulation device is used for measuring the perimeter of the positive feedback loop.
7. The inclinometer of any one of claims 3 to 6, wherein the fluid regions within each level sensor body are in communication and the gas regions within each level sensor body are in communication without an energy dissipating system at the second end of the hollow coax-Fabry-Perot resonator by:
the first end of the hollow coaxial cable-fabry-perot resonator of each level sensor is at the top: the second end of each liquid level sensor is of an open structure, each open structure is communicated with or submerged into a liquid area of the same closed container by using a communicating container, or the second end of each liquid level sensor is of a closed structure, an opening is formed in the shell wall corresponding to the liquid area in each liquid level sensor, and the communicating container is used for communicating or submerged into the liquid area of the same closed container between the openings; openings are formed in the shell wall corresponding to a gas area above the liquid level in each liquid level sensor, and each opening is communicated with each other through a vent pipe or is opened in the gas area of the same closed container;
the first end of the hollow coaxial cable-Fabry-Perot resonant cavity of each liquid level sensor is at the bottom: the second end of each liquid level sensor is of an open structure and is communicated with the corresponding gas area through a vent pipe, or the second end of each liquid level sensor is of a closed structure and is provided with an opening on the shell wall corresponding to the gas area above the liquid level in each liquid level sensor, and the openings are communicated with each other through the vent pipe; the liquid area inside each liquid level sensor corresponds to an opening on the shell wall, and each opening is communicated with a communicating container.
8. The inclinometer of any one of claims 3 to 6, wherein, in the case where a load resistor or coaxial load is connected between the outer shell and the inner rod of the second end of the hollow coaxial cable-Fabry-Perot resonator for dissipating energy, the liquid areas in each of the liquid level sensor bodies are kept connected, and the gas areas in each of the liquid level sensor bodies are kept connected, by:
the first end of the hollow coaxial cable-fabry-perot resonator of each level sensor is at the top: openings are formed in the shell wall corresponding to the liquid area inside each liquid level sensor, and each opening is communicated with the liquid area of the same closed container through a communicating container or is submerged in the liquid area of the same closed container; openings are formed in the shell wall corresponding to a gas area above the liquid level in each liquid level sensor, and each opening is communicated with each other through a vent pipe or is opened in the gas area of the same closed container;
the first end of the hollow coaxial cable-Fabry-Perot resonant cavity of each liquid level sensor is at the bottom: openings are formed in the shell wall corresponding to the liquid area inside each liquid level sensor, and communication containers are used for communication among the openings; openings are formed in the housing wall corresponding to the gas region above the liquid level in each liquid level sensor, and a vent pipe is used for communication between each opening.
9. The inclinometer of any one of claims 3 to 6, wherein the inclinometer comprises a liquid level sensor, the inclinometer being a unidirectional inclinometer having a hollow coax-Fabry-Perot resonator with a first end at the top, wherein:
the second end of the hollow coaxial cable-Fabry-Perot resonant cavity of the liquid level sensor is of an open structure, the open structure is connected with a U-shaped pipe, the liquid level sensor is communicated with a liquid area in the U-shaped pipe, and the liquid level sensor is communicated with a gas area above the liquid level of the U-shaped pipe through a vent pipe and used for eliminating the gas pressure difference between the liquid level sensor and the gas area of the U-shaped pipe.
10. The inclinometer according to any one of claims 3 to 6, wherein the inclinometer comprises two liquid level sensors, the inclinometer is a unidirectional inclinometer which does not need temperature compensation and rotates along with an object to be measured, and the first ends of the hollow coaxial cable-Fabry-Perot resonant cavities of the two liquid level sensors are both positioned at the top, wherein:
two level sensor are parallel and vertical placing, the inside liquid region of two level sensor uses the intercommunication container to communicate, the gas region more than two level sensor's the liquid level uses the breather pipe to communicate for eliminate the atmospheric pressure difference between the gas region more than the inside liquid level of two level sensor.
11. The inclinometer according to any one of claims 3 to 6, wherein the inclinometer comprises two liquid level sensors, the inclinometer is a unidirectional inclinometer which does not need temperature compensation and rotates along with an object to be measured, and the first ends of the hollow coaxial cable-Fabry-Perot resonant cavities of the two liquid level sensors are both positioned at the bottom, wherein:
the two liquid level sensors are arranged in parallel and vertically, a sealing plug is arranged in each of the bodies of the two liquid level sensors and used for ensuring that liquid is above the sealing plug, the top of the sealing plug or the bottom of the liquid is used as a first reflection point, the top of the liquid is used as a second reflection point, and the top of the liquid is always lower than the tops of the shell and the inner rod; the shell wall corresponding to the liquid areas in the two liquid level sensors is provided with an opening, the opening in the shell wall is positioned below the liquid level and above the sealing plug, and the two openings are communicated with the communicating container to enable the liquid areas in the two liquid level sensors to be communicated; and the gas areas above the liquid levels of the two liquid level sensors are communicated by using a vent pipe and are used for eliminating the gas pressure difference between the gas areas above the liquid levels in the two liquid level sensors.
12. The inclinometer according to any one of claims 3 to 6, wherein the inclinometer comprises two liquid level sensors, the inclinometer is a unidirectional inclinometer without temperature compensation, when the inclination angle of the inclinometer changes, the two liquid level sensors do not rotate, the first ends of the hollow coaxial cable-Fabry-Perot resonant cavities of the two liquid level sensors are both positioned at the top, and the inclinometer comprises:
the two liquid level sensors are arranged in parallel, the two liquid level sensors are respectively fixed on the substrate through a rotating shaft, so that the two liquid level sensors can rotate around the rotating shaft, the rotating shaft is arranged below the second reflection point, the rotating shaft is positioned on the axis of the liquid level sensors, and the connecting line of the rotating shafts of the two liquid level sensors is perpendicular to the axes of the two liquid level sensors; the bottom of each liquid level sensor is provided with a heavy hammer for ensuring that the axis of the liquid level sensor is always vertical when the base plate is driven to rotate after the inclination angle of the inclinometer is changed;
liquid areas in the two liquid level sensors are communicated by using a communicating container, and gas areas above the liquid levels of the two liquid level sensors are communicated by using a vent pipe, so that the pressure difference between the gas areas above the liquid levels in the two liquid level sensors is eliminated; wherein, the communicating container and the vent pipe both adopt flexible pipes to ensure that the liquid level sensor is not driven to rotate; or the whole system is placed into a closed container, liquid is filled at the bottom of the closed container, the shells and a part of the inner rod of the two liquid level sensors are all immersed into the liquid at the bottom of the closed container, liquid areas inside the two liquid level sensors are communicated with the liquid at the bottom of the closed container, and gas areas of the two liquid level sensors are communicated with gas above the liquid level of the closed container, so that the pressure difference between the gas areas above the liquid level inside the two liquid level sensors is eliminated.
13. The inclinometer according to any one of claims 3 to 6, wherein the inclinometer comprises two liquid level sensors, the inclinometer is a unidirectional inclinometer without temperature compensation, when the inclination angle of the inclinometer changes, the two liquid level sensors do not rotate, the first ends of the hollow coaxial cable-Fabry-Perot resonant cavities of the two liquid level sensors are both positioned at the top, and the inclinometer comprises:
the inclinometer comprises a closed container, two flexible ropes or two groups of flexible ropes with equal length are fixed on the top plate of the closed container, and a liquid level sensor is hung below each flexible rope or each group of flexible ropes, wherein a demodulation device of the liquid level sensor is arranged at the top of a hollow coaxial cable-Fabry-Perot resonant cavity and is hung below the flexible ropes, and the axis of the hung liquid level sensor is in the vertical direction; the bottom of the closed container is filled with liquid, a part of the outer shell and the inner rod of the two liquid level sensors is always immersed in the liquid at the bottom of the closed container, liquid areas in the two liquid level sensors are communicated with the liquid at the bottom of the closed container, and air holes are formed in the shell wall or the first end of the shell wall corresponding to the gas areas of the two liquid level sensors, so that the gas areas in the liquid level sensors are communicated with the gas above the liquid level of the closed container, and the air pressure difference between the gas areas above the liquid level in the two liquid level sensors is eliminated.
14. The inclinometer according to any one of claims 3 to 6, wherein the inclinometer comprises two liquid level sensors, the inclinometer is a unidirectional inclinometer which does not need temperature compensation and rotates along with an object to be measured, and the first ends of the hollow coaxial cable-Fabry-Perot resonant cavities of the two liquid level sensors are both positioned at the top, wherein:
the inclinometer comprises a closed container, wherein the two liquid level sensors are arranged in parallel and are rigidly fixed on the top plate or the bottom plate or the side surface of the closed container; the bottom of the closed container is filled with liquid, a part of the outer shell and the inner rod of the two liquid level sensors is always immersed in the liquid at the bottom of the closed container, liquid areas in the two liquid level sensors are communicated with the liquid at the bottom of the closed container, and air holes are formed in the shell wall or the first end of the shell wall corresponding to the gas areas of the two liquid level sensors, so that the gas areas in the liquid level sensors are communicated with the gas above the liquid level of the closed container, and the air pressure difference between the gas areas above the liquid level in the two liquid level sensors is eliminated.
15. The inclinometer according to any one of claims 3 to 6, wherein the inclinometer comprises three liquid level sensors, the inclinometer is a bidirectional inclinometer which does not need temperature compensation and rotates along with an object to be measured, and the first ends of the hollow coaxial cable-Fabry-Perot resonant cavities of the three liquid level sensors are all positioned at the top, wherein:
the three liquid level sensors are arranged in parallel and vertically, and the axes of the three liquid level sensors and three intersection points of a horizontal plane are not on the same straight line; liquid areas in the three liquid level sensors are communicated by using a communicating container; for the gas area above the liquid level inside the three liquid level sensors, the first liquid level sensor is communicated with the second liquid level sensor through a first vent pipe, the third liquid level sensor is communicated with the second liquid level sensor through a second vent pipe, and the first vent pipe and the second vent pipe are located above the liquid level and used for eliminating the gas pressure difference between the gas area above the liquid level inside the three liquid level sensors.
16. The inclinometer according to any one of claims 3 to 6, wherein the inclinometer comprises three liquid level sensors, the inclinometer is a bidirectional inclinometer without temperature compensation, when the inclination angle of the inclinometer changes, the three liquid level sensors do not rotate, the first ends of the hollow coaxial cable-Fabry-Perot resonant cavities of the three liquid level sensors are all positioned at the top, and the inclinometer comprises:
the inclinometer comprises a closed container, three flexible ropes or three groups of flexible ropes with equal length are fixed on a top plate of the closed container, and a liquid level sensor is hung below each flexible rope or each group of flexible ropes, wherein a demodulation device of the liquid level sensor is arranged at the top of a hollow coaxial cable-Fabry-Perot resonant cavity and is hung below the flexible ropes, and the axis of the hung liquid level sensor is in the vertical direction; the three intersection points of the axes of the three liquid level sensors and the horizontal plane are not on the same straight line; the bottom of the closed container is filled with liquid, a part of the outer shell and the inner rod of the three liquid level sensors is always immersed in the liquid at the bottom of the closed container, liquid areas in the three liquid level sensors are communicated with the liquid at the bottom of the closed container, and air holes are formed in the shell wall or the first end of the shell wall corresponding to the gas areas of the three liquid level sensors, so that the gas areas in the liquid level sensors are communicated with the gas above the liquid level of the closed container, and the air pressure difference between the gas areas above the liquid level in the three liquid level sensors is eliminated.
17. The inclinometer according to any one of claims 3 to 6, wherein the inclinometer comprises three liquid level sensors, the inclinometer is a bidirectional inclinometer which does not need temperature compensation and rotates along with an object to be measured, and the first ends of the hollow coaxial cable-Fabry-Perot resonant cavities of the three liquid level sensors are all positioned at the top, wherein:
the inclinometer comprises a closed container, the three liquid level sensors are arranged in parallel and are rigidly fixed on a top plate, a bottom plate or a side surface of the closed container, and three intersection points of the axes of the three liquid level sensors and a horizontal plane are not on the same straight line; the bottom of the closed container is filled with liquid, a part of the outer shell and the inner rod of the three liquid level sensors is always immersed in the liquid at the bottom of the closed container, liquid areas in the three liquid level sensors are communicated with the liquid at the bottom of the closed container, and air holes are formed in the shell wall or the first end of the shell wall corresponding to the gas areas of the three liquid level sensors, so that the gas areas in the liquid level sensors are communicated with the gas above the liquid level of the closed container, and the air pressure difference between the gas areas above the liquid level in the three liquid level sensors is eliminated.
18. The inclinometer of claim 15, wherein the three points of intersection of the axes of the three level sensors with the horizontal plane are not in a straight line, comprising at least:
the axes of the three liquid level sensors and three intersection points of the horizontal plane form a right triangle, and the two right-angle sides are respectively an X rotating shaft and a Y rotating shaft in the inclined direction.
19. The inclinometer of claim 16, wherein the three points of intersection of the axes of the three level sensors with the horizontal plane are not on a straight line, comprising at least:
the axes of the three liquid level sensors and three intersection points of the horizontal plane form a right triangle, and the two right-angle sides are respectively an X rotating shaft and a Y rotating shaft in the inclined direction.
20. The inclinometer of claim 17, wherein the three points of intersection of the axes of the three level sensors with the horizontal plane are not on a straight line, comprising at least:
the axes of the three liquid level sensors and three intersection points of the horizontal plane form a right triangle, and the two right-angle sides are respectively an X rotating shaft and a Y rotating shaft in the inclined direction.
21. The inclinometer of claim 15, wherein d is when the three intersection points of the axes of the three level sensors with the horizontal plane form an isosceles right triangle1＝d2。
22. The inclinometer of claim 16, wherein d is when the three intersection points of the axes of the three level sensors with the horizontal plane form an isosceles right triangle1＝d2。
23. The inclinometer of claim 17, wherein d is when the three intersection points of the axes of the three level sensors with the horizontal plane form an isosceles right triangle1＝d2。
24. The inclinometer according to any one of claims 18 to 20, wherein when the three intersections of the axes of the three level sensors with the horizontal plane form an isosceles right triangle, d is1＝d2。
25. The inclinometer according to any one of claims 3 to 6, wherein when the inclinometer comprises N liquid level sensors, N is an integer of 4 or more, and N intersection points of the axes of the N liquid level sensors and the horizontal plane are not on a straight line, the inclinometer can be used as a bidirectional inclinometer without temperature compensation.
CN201822057162.5U 2018-12-07 2018-12-07 Clinometer Active CN209927131U (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111288966A (en) * 2018-12-07 2020-06-16 江苏弘开传感科技有限公司 Clinometer
CN111481023A (en) * 2020-05-08 2020-08-04 郭春燕 Adjustable horizontal wall hanging support for auxiliary picture frame

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111288966A (en) * 2018-12-07 2020-06-16 江苏弘开传感科技有限公司 Clinometer
CN111481023A (en) * 2020-05-08 2020-08-04 郭春燕 Adjustable horizontal wall hanging support for auxiliary picture frame

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