CN204924167U - Two interdigital metal strain gauge of lateral deviation full -bridge of horizontal local derviation but measured surface meets an emergency - Google Patents

Abstract

A full-bridge double-interdigitated metal strain gauge capable of measuring the lateral deviation of the lateral deflection of the surface strain, including a base and four sensitive grids, each of which is connected to a lead wire at both ends, and each sensitive grid includes a sensitive section and the transition section, the axes of all sensitive sections are straight lines, arranged in parallel and in the same plane; in the plane determined by the axis of the sensitive section, the direction along the axis of the sensitive section is the axial direction, and the direction perpendicular to the axial direction is the transverse direction; The four sensitive grids have the same resistance, and the resistance changes under the same strain are the same. They are called the upper and lower sensitive grids, the upper and lower sensitive grids, the lower and upper sensitive grids and the lower and lower sensitive grids, and the upper and lower sensitive grids. There is an interdigitated arrangement between the sensitive grids, and an interdigitated arrangement between the lower upper sensitive grid and the lower lower sensitive grid; the centers of the four sensitive grids have no deviation in the axial direction, but have deviations in the lateral direction. The utility model can not only measure the strain, but also can effectively detect the lateral first-order and second-order partial derivatives of the surface strain.

Description

A full bridge double interdigitated metal strain gauge that can measure the lateral deviation of the lateral deflection of the surface strain

technical field

The utility model relates to the field of sensors, in particular to a metal strain gauge.

Background technique

The working principle of the metal resistance strain gauge is the resistance strain effect, that is, when the metal wire is subjected to strain, its resistance changes correspondingly with the magnitude of the mechanical deformation (stretch or compression). The theoretical formula for the resistance strain effect is as follows:

$\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&rho;</span>}\frac{\mathrm{<span\; class="notranslate">\; L</span>}}{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Where R is its resistance value, ρ is the resistivity of the metal material, L is the length of the metal material, and S is the cross-sectional area of the metal material. During the process of mechanical deformation of the metal wire under strain, ρ, L, and S will all change, which will inevitably cause changes in the resistance value of the metal material. When the metal material is stretched, the length increases, the cross-sectional area decreases, and the resistance value increases; when it is compressed, the length decreases, the cross-sectional area increases, and the resistance value decreases. Therefore, as long as the change of the resistance value can be measured, the strain of the metal wire can be known. The formula for the resistance change rate of metal materials can be derived from formula (1) and related knowledge of material mechanics

$\frac{\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; R</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; K</span>}\frac{\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; L</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; K</span>}\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Among them, ΔR is the change in resistance, ΔL is the change in the length of the metal material in the direction of tension or pressure, ε is the strain in the same direction, often called axial strain, and K is the strain sensitivity coefficient of the metal material.

In practical applications, the metal resistance strain gauge is pasted on the surface of the elastic element of the sensor or the mechanical part to be tested. When the elastic element in the sensor or the mechanical part under test is subjected to force to generate strain, the strain gauge pasted on it will also undergo the same mechanical deformation, causing a corresponding change in the resistance of the strain gauge. At this time, the resistance strain gauge converts the mechanical quantity into the output of the change of resistance.

But sometimes we also need to know the partial derivative of the workpiece strain. For example, there are three occasions below, but not limited to these three. The partial derivative of the workpiece surface strain is required:

First, due to the strain concentration near the sudden change in the shape of the workpiece, it is often the first place where the workpiece is damaged. Monitoring the partial strain derivative near the sudden change in shape can intuitively obtain the degree of strain concentration there.

Second, there are a large number of bending parts in buildings, bridges, and mechanical equipment. The knowledge of material mechanics tells us that the axial strain on the surface of a curved beam is proportional to the section bending moment, and the axial partial derivative of the section bending moment and the section shear strain become Proportional, that is, the cross-sectional shear strain can be obtained through the axial partial derivative of the surface axial strain, and the shear strain cannot be directly measured on the workpiece surface with a strain gauge;

Third, when using elastic mechanics to study workpiece strain, the internal strain is determined by partial differential equations, and the solution of the equation requires boundary conditions, and the partial derivative of workpiece surface strain is one of the boundary conditions, which cannot be provided by general strain gauges.

Contents of the invention

In order to overcome the deficiency that the existing metal strain gauges cannot detect the strain deflection, the utility model provides a lateral deviation of the surface strain lateral deflection that can measure the strain and can effectively detect the lateral first-order and second-order deflection of the surface strain Full bridge double interdigitated metal strain gauge.

The technical scheme that the utility model solves its technical problem adopts is:

A full-bridge double-interdigitated metal strain gauge capable of measuring the lateral deviation of the surface strain lateral deflection, including a base, and the metal strain gauge also includes four sensitive grids, each of which is connected to a lead wire at both ends, The four sensitive grids are fixed on the base;

Each sensitive grid includes a sensitive section and a transition section, the two ends of the sensitive section are transition sections, the sensitive section is in the shape of a long and thin strip, the transition section is in a thick and short shape, and the resistance of the sensitive section is much greater than the The resistance of the transition section, the resistance change value of the sensitive section under the same strain state is much greater than the resistance change value of the transition section, and the resistance change value of the transition section is close to 0;

All the centroids of the cross-sections of each sensitive section constitute the axis of the sensitive section. The axis of the sensitive section is a straight line segment. The axes of the sensitive sections are parallel and located in the same plane. In the plane defined by the axes of the sensitive section, The direction is the axial direction, and the direction perpendicular to the axial direction is the transverse direction; the shape and size of all cross-sections of each sensitive section are consistent; take the midpoint position of the axis of each sensitive section and use the resistance value of the sensitive section to form the nominal mass of the sensitive section The nominal mass point of each sensitive section, the centroid position formed by the nominal mass points of each sensitive section is the center of the sensitive grid;

The total resistances of the sensitive sections of the four sensitive grids are consistent, and the total resistance change values of the sensitive sections of the four sensitive grids are consistent under the same strain. The centers of the four sensitive grids are located on a straight line, and the straight line is perpendicular to the four sensitive grids. For any axis of the sensitive section of the grid, the four sensitive grids are called upper upper sensitive grid, lower upper sensitive grid, lower upper sensitive grid and lower lower sensitive grid from top to bottom along this straight line direction; on the plane determined by the axes of each sensitive section, There is an interdigitated arrangement between the upper and upper sensitive grids and the upper and lower sensitive grids, and an interdigitated arrangement between the lower and upper sensitive grids and the lower and lower sensitive grids;

The centers of the four sensitive grids have no deviation in the axial direction, but have deviations in the lateral direction. The distance between the center of the upper and lower sensitive grids is Δy ₁ ; the distance between the centers of the upper and lower sensitive grids and the center of the lower and upper sensitive grids is Δy ₂ , The distance between the center of the lower and upper sensitive grid and the center of the lower and lower sensitive grid is Δy ₃ , the distance between the center of the upper and upper sensitive grid and the center of the lower and upper sensitive grid is Δy ₄ = Δy ₁ + Δy ₂ , the distance between the center of the upper and lower sensitive grid and the center of the lower and lower sensitive grid Δy ₅ =Δy ₂ +Δy ₃ , the distance between the center of the upper sensitive grid and the center of the lower sensitive grid is Δy ₆ =Δy ₁ +Δy ₂ +Δy ₃ .

In the utility model, the total resistances of the sensitive sections of the four sensitive grids should be the same, and the changes in the total resistances of the sensitive sections of the four sensitive grids should be consistent under the same strain. Since the measurement bridge has four bridge arms, the four sensitive gates can be arranged in the four bridges in a certain order, so this strain gauge is called a full bridge. For example, the cross-sections of the sensitive sections of the four sensitive grids are all the same, the materials are consistent, and the sum of the lengths of the sensitive sections of the four sensitive grids is equal.

The distance Δy ₁ between the upper and lower sensitive grids and the center of the upper and lower sensitive grids is generally smaller than or even much smaller than the length of each sensitive section. The sensitive sections of the two sensitive gates are distributed alternately in the vertical direction, and there is no restriction on the order and times of the sensitive sections of the two sensitive gates appearing in this direction. Similarly, the lower upper sensitive grid and the lower lower sensitive grid are also interdigitated. However, neither the upper upper sensitive grid nor the lower upper sensitive grid nor the lower lower sensitive grid is interdigitated; Neither the sensitive grid nor the upper and lower sensitive grids are interdigitated; neither the lower lower sensitive grid nor the upper upper sensitive grid nor the upper and lower sensitive grids are interdigitated. Since the relative positions of the upper and lower sensitive grids, the upper and lower sensitive grids, the upper and lower sensitive grids and the lower and lower sensitive grids are fairly accurately fixed by the strain gauge production process, this is also one of the keys for the utility model to detect the lateral partial derivative of workpiece strain. one.

Using the linear relationship between the resistance change value and strain of metal materials, first, it can be used to measure strain like ordinary strain gauges; second, the resistance difference between any two of the four sensitive grids and the center of the two sensitive grids The distance ratio reflects the lateral deflection of the strain; third, the difference between the sum of the resistances of the lower and upper sensitive grids minus the sum of the resistances of the upper and lower sensitive grids and the lower and upper sensitive grids and the axial second-order deflection of the strain Proportional.

In the process, care should be taken to keep the total resistance of the transition section of each sensitive gate and the change of the transition section resistance under external strain consistent to increase the measurement accuracy. If the resistance of the transition section and the change of resistance under strain cannot be ignored, it can also be used as a system error. Eliminated during detection.

Further, the upper upper sensitive grid and the lower upper sensitive grid, and the lower upper sensitive grid and the lower lower sensitive grid are mirror-symmetrically arranged around the central x-axis. That is, Δy ₁ =Δy ₃ . Of course, other schemes in which the two are not equal can also be adopted.

Further, the metal strain gauge also includes a cover sheet, and the cover sheet covers the sensitive grid and the base.

Still further, the sensitive grid is a wire-type, foil-type, film-type or thick-film-type sensitive grid.

Furthermore, the base is an adhesive film base, a glass fiber base, an asbestos base, a metal base or a temporary base.

The four sensitive gates are arranged on the substrate from top to bottom. Of course, other arrangements are also possible.

The beneficial effects of the utility model are mainly manifested in that not only the surface strain of the workpiece can be measured, but also the lateral first-order and second-order partial derivatives of the surface strain can be effectively detected.

Description of drawings

Fig. 1 is a schematic diagram of a full-bridge double-interdigitated metal strain gauge capable of measuring the lateral deviation of the lateral deflection of the surface strain.

Fig. 2 is a top view of a full-bridge double-interdigitated metal strain gauge capable of measuring lateral deviation of surface strain lateral deflection.

Figure 3 is a schematic diagram of the measuring bridge.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described.

Referring to Figures 1 to 3, a full-bridge double-interdigitated metal strain gauge that can measure the lateral deviation of the lateral deflection of the surface strain includes a base, and the metal strain gauge also includes four sensitive grids, each of which has two sensitive grids. The terminals are respectively connected to a lead wire, and the four sensitive grids are fixed on the substrate;

Each sensitive grid includes a sensitive section and a transition section, the two ends of the sensitive section are transition sections, the sensitive section is in the shape of a long and thin strip, the transition section is in a thick and short shape, and the resistance of the sensitive section is much greater than the The resistance of the transition section, the resistance change value of the sensitive section under the same strain state is much greater than the resistance change value of the transition section, and the resistance change value of the transition section is close to 0;

All the centroids of the cross-sections of each sensitive section constitute the axis of the sensitive section. The axis of the sensitive section is a straight line segment. The axes of the sensitive sections are parallel and located in the same plane. In the plane defined by the axes of the sensitive section, The direction is the axial direction, and the direction perpendicular to the axial direction is the transverse direction; the shape and size of all cross-sections of each sensitive section are consistent; take the midpoint position of the axis of each sensitive section and use the resistance value of the sensitive section to form the nominal mass of the sensitive section The nominal mass point of each sensitive section, the centroid position formed by the nominal mass points of each sensitive section is the center of the sensitive grid;

The total resistances of the sensitive sections of the four sensitive grids are consistent, and the total resistance change values of the sensitive sections of the four sensitive grids are consistent under the same strain. The centers of the four sensitive grids are located on a straight line, and the straight line is perpendicular to the four sensitive grids. For any axis of the sensitive section of the grid, the four sensitive grids are called upper upper sensitive grid, lower upper sensitive grid, lower upper sensitive grid and lower lower sensitive grid from top to bottom along this straight line direction; on the plane determined by the axes of each sensitive section, There is an interdigitated arrangement between the upper and upper sensitive grids and the upper and lower sensitive grids, and an interdigitated arrangement between the lower and upper sensitive grids and the lower and lower sensitive grids;

The centers of the four sensitive grids have no deviation in the axial direction, but have deviations in the lateral direction. The distance between the center of the upper and lower sensitive grids is Δy ₁ ; the distance between the centers of the upper and lower sensitive grids and the center of the lower and upper sensitive grids is Δy ₂ , The distance between the center of the lower and upper sensitive grid and the center of the lower and lower sensitive grid is Δy ₃ , the distance between the center of the upper and upper sensitive grid and the center of the lower and upper sensitive grid is Δy ₄ = Δy ₁ + Δy ₂ , the distance between the center of the upper and lower sensitive grid and the center of the lower and lower sensitive grid Δy ₅ =Δy ₂ +Δy ₃ , the distance between the center of the upper sensitive grid and the center of the lower sensitive grid is Δy ₆ =Δy ₁ +Δy ₂ +Δy ₃ .

In this embodiment, the lateral deviation of the lateral deflection of the surface strain lateral deflection can be measured, and the full-bridge double-interdigitated metal strain gauge includes a base 1. According to the order of left and right in FIG. Grid 4, lower and lower sensitive grid 5, eight lead wires 6, can also have cover sheet (not shown in each accompanying drawing).

Upper and lower sensitive grids 2, upper and lower sensitive grids 3, lower upper sensitive grids 4 and lower lower sensitive grids 5 can be fixed on the base 1 to keep the fixed shape, position and size of each sensitive grid; the base 1 is very thin, so that the The strain on the surface of the test piece is accurately transferred to the upper and lower sensitive grids 2 , the upper and lower sensitive grids 3 , the upper and lower sensitive grids 4 and the lower and lower sensitive grids 5 . The substrate 1 can be an adhesive film substrate, a fiberglass substrate, an asbestos substrate, a metal substrate, and a temporary substrate. The substrate is usually fixed on the tested part of the test piece by means of bonding, welding, ceramic spraying and the like. Some lines for positioning the strain gauges can also be printed on the substrate 1 .

The cover sheet is made of paper or glue, covering the upper and upper sensitive grids 2, the upper and lower sensitive grids 3, the upper and lower sensitive grids 4, the lower and lower sensitive grids 5 and the base 1, and plays the role of moisture-proof, corrosion-proof, damage-proof, etc. protective layer.

The lead 6 is used to connect the sensitive grid and the measuring circuit. The upper and upper sensitive grid 2, the upper and lower sensitive grid 3, the lower upper sensitive grid 4 and the lower and lower sensitive grid 5 each have two lead wires 6, which are compatible with foil and membrane strain gauges. The lead wire 6 is integrated with the upper and lower sensitive grids 2 , the upper and lower sensitive grids 3 , the upper and lower sensitive grids 4 or the lower and lower sensitive grids 5 connected thereto. The pins of the upper and upper sensitive grid 2 are 6-1 and 6-2, the pins of the upper and lower sensitive grid 3 are 6-3 and 6-4, and the pins of the lower and upper sensitive grid 4 are 6-5 and 6-6, The pins of the lower sensitive grid 5 are 6-7 and 6-8.

The upper and upper sensitive grids 2, the upper and lower sensitive grids 3, the upper and lower sensitive grids 4 and the lower and lower sensitive grids 5 can be wire type, foil type, thin film type, thick film type according to their metal sensitive materials and processing technology. Regardless of the thickness of the upper and lower sensitive grid 2, the upper and lower sensitive grid 3, the upper and lower sensitive grid 4 and the lower and lower sensitive grid 5, the thicknesses are very small, so that the upper and lower sensitive grid 2, the upper and lower sensitive grid 3, the lower upper sensitive grid 4 and the lower sensitive grid The axial length of the lower sensitive grid 5 varies with the deformation of the workpiece to which it is attached. The basic innovation of the utility model lies in the cooperation between the upper and lower sensitive grids 2, the upper and lower sensitive grids 3, the upper and lower sensitive grids 4 and the lower and lower sensitive grids 5. The main points are as follows:

First, four sensitive gates are arranged on the substrate, which are called upper and upper sensitive gates 2 , upper and lower sensitive gates 3 , lower upper sensitive gates 4 and lower and lower sensitive gates 5 .

Second, the upper and lower sensitive grid 2, the upper and lower sensitive grid 3, the upper and lower sensitive grid 4 and the lower and lower sensitive grid 5 can be divided into a plurality of transition sections 7 and a plurality of sensitive sections 8, and each transition section 7 is connected to each sensitive section 8. connected to form a sensitive gate. In comparison, the sensitive section 8 is elongated, has a large resistance and its resistance is more sensitive to strain; the transition section 7 is basically thick and short, so that the resistance of the transition section is small and insensitive to strain, In the working state, the resistance change is close to 0, so the sum of the resistance of the sensitive section is basically the total resistance of a single sensitive grid. Figure 2 marks the sensitive section 8 and the transition section 7 in more detail for a clearer perspective.

Third, the upper and lower sensitive grid 2, the upper and lower sensitive grid 3, the lower upper sensitive grid 4 and the lower lower sensitive grid 5 have the same cross-section of the sensitive section 8, and the upper upper sensitive grid 2, the upper and lower sensitive grid 3, and the lower upper sensitive grid 4 and the sum of the respective sensitive section 8 lengths of the lower and lower sensitive grids 5 are the same. Neglecting the resistance of the transition section 7, the total resistances of the upper and upper sensitive gates 2, the upper and lower sensitive gates 3, the lower and upper sensitive gates 4 and the lower and lower sensitive gates 5 are all equal, and the total resistance of the sensitive sections of the four sensitive gates changes under the same strain The amount should be consistent.

Fourth, the sensitive section 8 of each sensitive grid is in the shape of a long and thin strip, and the centroids of all the cross-sections of each sensitive section 8 form the axis of the sensitive section. The axis of the sensitive section 8 is a straight line segment, and the axes of each sensitive section 8 are parallel. and lie in the same plane. The projection shapes of all cross sections of each sensitive section 8 along the axis direction of the sensitive section are consistent. Take the midpoint position of the axis of each sensitive section and use the resistance value of the sensitive section to form the nominal mass of the sensitive section. The centroid position formed by the nominal mass points of each sensitive section is the center of the sensitive grid.

Fifth, looking down at the upper and lower sensitive grids 2, the upper and lower sensitive grids 3, the upper and lower sensitive grids 4 and the lower and lower sensitive grids 5, each of their sensitive sections has a symmetry axis and the symmetry axes coincide (the y axis in Fig. 2), The sensitive sections 8 of the upper and lower sensitive grids 2 , the upper and lower sensitive grids 3 , the upper and lower sensitive grids 4 and the lower and lower sensitive grids 5 are all perpendicular to the axis of symmetry. Each sensitive segment 8 in the upper and lower sensitive grid 2 , the upper and lower sensitive grid 3 , the lower upper sensitive grid 4 and the lower and lower sensitive grid 5 starts and ends in the same position along the x-axis direction in FIG. 2 . Therefore, it can be said that the upper and upper sensitive grid 2, the upper and lower sensitive grid 3, the lower upper sensitive grid 4 and the lower lower sensitive grid 5 have no axial deviation and only lateral deviation, that is, the upper and upper sensitive grid 2, the upper and lower sensitive grid 3, and the lower and upper sensitive grid 4 and the center positions of the lower and lower sensitive grids 5 are all on the y-axis. According to the top view of the strain gauge in Figure 2, the center of the upper and upper sensitive grid 2 is at the intersection of the y axis and the x _UU axis, the center of the upper and lower sensitive grid 3 is at the intersection of the y axis and the x _UL axis, and the center of the lower and upper sensitive grid 4 is at the intersection of the y axis and the x UL axis. The intersection of the y axis and the x _LU axis, the center of the lower and lower sensitive grid 5 is at the intersection of the y axis and the x _LL axis. The midpoint of the connecting line between the center of the upper and lower sensitive grid 2 and the center of the upper and lower sensitive grid 3 is the intersection of the y axis and the x _U axis, and the midpoint of the connecting line between the center of the upper and lower sensitive grid 4 and the center of the lower and lower sensitive grid 5 is the y axis and the x axis Intersection of the _L axis.

Sixth, the upper and upper sensitive grids 2 are interdigitated with the upper and lower sensitive grids 3, and the upper and lower sensitive grids 4 are interdigitated with the lower and lower sensitive grids 5. The central positions of these sensitive grids are all on the same symmetry axis y-axis. It can be noticed that the direct result of the interdigitation arrangement is that the center of the upper and upper sensitive grid 2 is relatively close to the center of the upper and lower sensitive grid 3, and the distance is Δy ₁ ; the distance between the center of the upper and lower sensitive grid 3 and the center of the lower upper sensitive grid 4 is Δy ₂ , The distance between the center of the lower and upper sensitive grid 4 and the center of the lower and lower sensitive grid 5 is Δy ₃ , the distance between the center of the upper and upper sensitive grid 2 and the center of the lower and upper sensitive grid 4 is Δy ₄ =Δy ₁ +Δy ₂ , the center of the upper and lower sensitive grid 3 and the center of the lower The distance between the center of the lower sensitive grid 5 is Δy ₅ =Δy ₂ +Δy ₃ , and the distance between the center of the upper upper sensitive grid 2 and the center of the lower lower sensitive grid 5 is Δy ₆ =Δy ₁ +Δy ₂ +Δy ₃ , as shown in Figure 2, this All six distances are lateral distances. Since the upper and lower sensitive grids 2, the upper and lower sensitive grids 3, the relative positions of the upper and lower sensitive grids 4 and the lower and lower sensitive grids 5 are guaranteed to be quite accurately fixed by the strain gauge production process, this is why the utility model can detect the lateral deviation of workpiece strain. One of the keys to guidance.

In summary, the upper and lower sensitive grids 2, the upper and lower sensitive grids 3, the upper and lower sensitive grids 4 and the lower and lower sensitive grids 5 of the utility model are equal in size, and there is no axial deviation between the sensitive grids but only lateral deviations. The center forms six different lateral deviations.

The resistance of the upper and upper sensitive grids is marked as R _UU , the resistance of the upper and lower sensitive grids is marked as R _UL , the resistance of the lower and upper sensitive grids is marked as R _LU , and the resistance of the lower and lower sensitive grids is marked as R _LL . In the free state, the resistances of the four sensitive gates are equal to R ₀ . When the strain gage of the present utility model is placed on a certain strained surface, two sensitive grids are taken in it, and the two must have one upper and one lower. The resistance of the upper sensitive grid is recorded as R ₀ +ΔR _u , the resistance of the lower sensitive grid is recorded as R ₀ +ΔR _l , the distance between the two sensitive grids is Δy _i , and i is one of 1 to 6. The difference in the strain at the center of the two sensitive grids causes the difference in the resistance variation between the two. The relationship between the sensitive grid resistance and the surface strain is:

$\frac{<span\; class="notranslate">\; \&part;</span>\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}{<span\; class="notranslate">\; \&part;</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}}{<span\; class="notranslate">\; |</span>}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; =</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; the\; y</span>}}}<span\; class="notranslate">\; =</span>\underset{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Right\; Arrow;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; lim</span>}}\frac{{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}}{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; \&ap;</span>\frac{\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

Where i=1,2,...,6, ε _u is the strain at the center of the upper sensitive grid, ε _l is the strain at the lower sensitive grid, and y is the midpoint of the line connecting the centers of the two sensitive grids. This is the principle of the utility model for measuring the axial deflection of the surface strain. The above formula is actually a numerical calculation of the partial derivative. According to the theory of numerical differentiation, this is to calculate the differential with Δy _i /2 as the step size. The error of the partial derivative calculation is not more than $o\left(\frac{{{\mathrm{\&Delta;y}}_i}^2}{4}\right)$ level, which is The high-order infinitesimal quantity has relatively high precision. Utilize the four strain gauges of the strain gauge of the utility model, limit the Δy ₁ =Δy ₃ of the strain gauge, use the relationship between the sensitive grid resistance and the surface strain and the numerical calculation method of the second order partial derivative as follows:

$\begin{array}{c}\frac{{<span\; class="notranslate">\; \&part;</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}{<span\; class="notranslate">\; \&part;</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{<span\; class="notranslate">\; |</span>}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; =</span>\underset{\underset{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&Right\; Arrow;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Right\; Arrow;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; lim</span>}}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; L</span>}}}{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}\mathrm{<span\; class="notranslate">\; L</span>}}}{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ <span\; class="notranslate">\; =</span>\underset{\underset{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&Right\; Arrow;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Right\; Arrow;</span>\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; lim</span>}}\frac{{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}\mathrm{<span\; class="notranslate">\; L</span>}}}{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}\\ <span\; class="notranslate">\; \&ap;</span>\frac{\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Where _y0 is the midpoint position of the center of the four sensitive grids of the strain gauge, that is, the intersection of the x-axis and the y-axis in Figure 2, ε _UU is the strain at the center of the upper and upper sensitive grids, and ε _UL is the strain at the center of the upper and lower sensitive grids, ε _LU is the strain at the center of the lower and upper sensitive grids, and ε _LL is the strain at the center of the lower and lower sensitive grids.

This embodiment can be used to measure strain and strain transverse deflection by combining this embodiment with an electric bridge. Assuming that the input voltage of the electric bridge is u _i and the output voltage is u _o , the schematic diagram of the measuring electric bridge is shown in FIG. 3 . When there is no workpiece strain, the resistances of the bridge arms of the bridge are respectively marked as R ₁ , R ₂ , R ₃ , and R ₄ in the clockwise direction, and these symbols are also used to mark the bridge where the resistance is located if there is no confusion. Sensitive gates or resistors of strain gauges can be placed on each bridge. Same as the general arrangement of strain gauges, if sensitive grids are installed on multiple bridge arms, there are qualitative requirements for the order and strain of each installation position. When there is no workpiece strain, the output voltage formula of the bridge is

${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; ;</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

At this time, it is required that the bridge balance is u _o = 0, so the so-called bridge balance condition R ₁ R ₃ -R ₂ R ₄ = 0 must be satisfied, and the bridge used further satisfies

R ₁ =R ₂ =R ₃ =R ₄ , (6)

Because, first, when the condition (6) is satisfied, the sensitivity of the strain gauge is the highest according to the relevant theory; second, the method of measuring the strain or the lateral deflection of the strain requires the condition (6) to be established. When the strain gage also strains with the external strain, the above bridge equilibrium condition is generally no longer valid, at this time

$\begin{array}{c}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; )</span>}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; +</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; +</span>}{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; +</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}\mathrm{<span\; class="notranslate">\; +</span>}{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\\ <span\; class="notranslate">\; \&ap;</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; +</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\\ <span\; class="notranslate">\; \&ap;</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;R</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 4</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

Since ΔR _i << R _i (i=1,2,3,4) the first ≈, the second ≈negligible part ΔR ₁ ΔR ₃ -ΔR ₂ ΔR ₄ is also very small, and can be used in engineering It is much smaller than the more reserved part. Generally, the voltage obtained by formula (7) can be used to measure the strain; for the strain transverse deflection, formula (3), formula (4) and formula (7) can be combined to rationally design and arrange the sensitive gates and resistors of each bridge arm to obtain The voltage value u _o with which the first-order partial conduction or the second-order partial conductance is linearly related, and this voltage is a weak signal that needs to be amplified.

Claims (5)

1. one kind can strain the two interdigitated metal foil gauge of lateral deviation full-bridge of horizontal local derviation by measured surface, comprise substrate, it is characterized in that: described metal strain plate also comprises four sensitive grids, the two ends of each sensitive grid connect an extension line respectively, described substrate are fixed described four sensitive grids;

Each sensitive grid comprises sensitive segment and transition section, the two ends of described sensitive segment are transition section, described sensitive segment is elongated strip shaped, described transition section is tubbiness shape, the resistance of described sensitive segment is much larger than the resistance of described transition section, under same strain state, the increased resistance value of described sensitive segment is much larger than the increased resistance value of described transition section, and the increased resistance value of described transition section is close to 0;

All xsect centres of form of each sensitive segment form sensitive segment axis, this sensitive segment axis is straight line section, the axis being parallel of each sensitive segment and be arranged in same plane, and sensitive segment axis is determined in plane, along described sensitive segment axis direction namely axially, be laterally with axially vertical direction; All shape of cross section consistent size of each sensitive segment; Get the axis point midway of each sensitive segment and with this sensitive segment resistance value for nominal mass is formed the nominal particle of place sensitive segment, the centroid position that the nominal particle of each sensitive segment is formed jointly is the center of sensitive grid;

The sensitive segment all-in resistance of four sensitive grids is consistent, described four sensitive grids all-in resistance changing value of sensitive segment under identical strain is consistent, four sensitive grids be centrally located on straight line, this straight line is perpendicular to four any sensitive segment axis of sensitive grid, four sensitive grids are called upper sensitive grid from top to bottom along this rectilinear direction, upper and lower sensitive grid, lower upper sensitive grid and lower sensitive grid; Each sensitive segment axis is determined in plane, in interdigital layout between upper sensitive grid and upper and lower sensitive grid, also in interdigital layout between lower upper sensitive grid and lower sensitive grid;

Four sensitive grid center bias frees in the axial direction, have deviation in the horizontal, and the distance at upper sensitive grid center and upper and lower sensitive grid center is Δ y ₁; The distance at upper and lower sensitive grid center and lower upper sensitive grid center is Δ y ₂, lower upper sensitive grid center and lower sensitive grid centre distance are Δ y ₃, the distance at upper sensitive grid center and lower upper sensitive grid center is Δ y ₄=Δ y ₁+ Δ y ₂, upper and lower sensitive grid center and lower sensitive grid centre distance are Δ y ₅=Δ y ₂+ Δ y ₃, upper sensitive grid center and lower sensitive grid centre distance are Δ y ₆=Δ y ₁+ Δ y ₂+ Δ y ₃.

2. can strain the two interdigitated metal foil gauge of lateral deviation full-bridge of horizontal local derviation by measured surface as claimed in claim 1, it is characterized in that: described metal strain plate also comprises cover plate, described cover plate is covered in described sensitive grid and substrate.

3. can strain the two interdigitated metal foil gauge of lateral deviation full-bridge of horizontal local derviation by measured surface as claimed in claim 1 or 2, it is characterized in that: described sensitive grid is wire form, foil, diaphragm type or thick-film type sensitive grid.

4. can strain the two interdigitated metal foil gauge of lateral deviation full-bridge of horizontal local derviation by measured surface as claimed in claim 1 or 2, it is characterized in that: described substrate is glued membrane substrate, glass fabric substrates, asbestos substrate, metallic substrates or temporary substrate.

5. can strain the two interdigitated metal foil gauge of lateral deviation full-bridge of horizontal local derviation by measured surface as claimed in claim 1 or 2, it is characterized in that: described four sensitive grids are arranged in substrate from top to bottom.