JP5078190B1 - Level - Google Patents

Abstract

An object of the present invention is to provide a level which can measure an inclined state without being affected by a change in the size of bubbles, facilitates measurement work, and suppresses manufacturing costs.
A level 1 includes a measurement base 2 provided with a reference surface 2A that comes into contact with a measurement surface, a pair of liquid levels 8 and a first bubble 10 enclosed therein. The first bubble tube 6 </ b> A and the second bubble tube 6 </ b> B mounted on the measurement base 2 are connected to each other so that the one bubble 10 is movably communicated.
[Selection] Figure 1

Description

  The present invention relates to a spirit level.

  Conventionally, a scale is written on the surface of a level with a single bubble tube, and the amount of movement of the bubble accompanying the inclination of the measurement surface is read on the scale to measure the amount of inclination. This scale is expressed as 0.02 mm / m as the amount of inclination per scale = sensitivity, and the amount of inclination is measured from the amount of movement of bubbles relative to the scale.

  However, if the bubble size changes due to the temperature of the measurement environment, the change becomes a measurement error. That is, in order to accurately measure the amount of inclination, the size of the bubbles at the time of measurement must be a prescribed size. Therefore, in order to perform accurate measurement, JIS B7510 clearly states that the bubble size is adjusted so that the bubble size is the same as the measurement scale described in advance as a measurement preparation work. Therefore, the certified level is also provided with a bubble chamber for adjusting the size of the bubble (see, for example, Patent Document 1).

JP 2004-163381 A

However, the above-described conventional level needs to be checked and adjusted for the bubble size each time measurement is performed, and the bubble chamber for that purpose is an increase factor in manufacturing cost.
The present invention has been made in view of the above circumstances, and provides a level that can measure an inclined state without being affected by a change in the size of bubbles, facilitates measurement work, and suppresses manufacturing costs. The purpose is to do.

The present invention employs the following means in order to solve the above problems.
The spirit level according to the present invention includes a measurement base having a reference surface that is in contact with the measurement surface, a pair of liquids and one first bubble enclosed therein, and the first bubble moves A first bubble tube and a second bubble tube that are connected to each other so as to communicate with each other and placed on the measurement base, and the first bubble tube and the second bubble tube are on the distal side. The base end side is arranged to be inclined with respect to the reference plane in a direction away from the reference plane, and the first bubble is formed to have a dimension extending from the first bubble tube to the second bubble tube . It is characterized by.

In the present invention, when the measurement surface is inclined with respect to the horizontal plane, when the reference surface is brought into contact with the measurement surface, the first bubbles move inside the proximal ends of the first bubble tube and the second bubble tube, The relative position of the bubble end on the first bubble tube side and the bubble end on the second bubble tube side varies. At this time, the degree of inclination of the measurement surface can be measured by measuring the variation in the distance between the bubble ends. In addition, since the first bubbles are always arranged on the base end side of the first bubble tube and the second bubble tube by being inclined, the first bubbles can be moved smoothly while being integrated. The amount of difference between the bubble ends can be suitably measured.

In addition, the level according to the present invention is the level, and includes a sensitivity adjustment unit that varies an inclination angle of the first bubble tube and the second bubble tube with respect to the reference plane.

  In the present invention, when the inclination angle is changed, the contact area between the first bubble and the inner wall of each bubble tube can be changed, and the movement sensitivity of the first bubble can be changed. For example, when the inclination angle is increased, the contact area between the first bubble and the inner wall of each bubble tube is reduced, so that the movement sensitivity of the first bubble can be reduced.

  Moreover, the level according to the present invention is the level, wherein the first bubble tube and the second bubble tube are formed symmetrically with respect to the first central axis.

  According to the present invention, the manufacturing cost can be further suppressed, and the positioning of the first bubble and the reading of the difference amount between the bubble ends can be more easily performed.

  The level according to the present invention is the level, and includes a plurality of scales arranged at regular intervals in the movement region of the bubble end of the first bubble in the first bubble tube and the second bubble tube. It has the scale part which has, It is characterized by the above-mentioned.

  According to the present invention, the distance between the bubble end on the first bubble tube side and the bubble end on the second bubble tube side can be measured more easily and accurately.

  The level according to the present invention is the level, wherein the scale portion is arranged to be movable with respect to the first bubble tube and the second bubble tube.

  According to the present invention, by moving the scale portion, each bubble end of the first bubble can always be on the scale, and the distance between the bubble ends can be measured more suitably.

  Further, the level according to the present invention is the level, which is formed as a pair, in which a liquid and one second bubble are enclosed, and the base ends of the second bubble are movably communicated with each other. A third bubble tube and a fourth bubble tube that are connected to each other and placed on the measurement base; a proximal end side of the first bubble tube and the second bubble tube; and the third bubble tube and the fourth bubble tube. The base end side of the bubble tube is arranged to face each other.

  This invention measures the measurement surface at a position where the distance between the bubble ends of the first bubble tube and the second bubble tube and the distance between the bubble ends of the third bubble tube and the fourth bubble tube are the same. By doing so, the absolute amount of the inclination angle of the measurement surface can be measured.

  The level according to the present invention is the level, wherein the proximal ends of the third bubble tube and the fourth bubble tube communicate with the proximal ends of the first bubble tube and the second bubble tube. And the first bubble and the second bubble are arranged as one bubble.

  According to the present invention, it is not necessary to adjust the first bubble tube and the second bubble tube, and the third bubble tube and the fourth bubble tube, respectively, at the time of manufacturing, and the manufacturing cost can be further suppressed.

  Moreover, the level according to the present invention is the level, wherein the third bubble tube and the fourth bubble tube are formed symmetrically with respect to the second central axis.

  According to the present invention, the manufacturing cost can be further suppressed, and the alignment of the bubbles in the third bubble tube and the fourth bubble tube and the reading of the difference amount between the bubble ends can be more easily performed.

  The spirit level according to the present invention is the spirit level, and is formed in a pair and connected to the base end sides of the first bubble tube and the second bubble tube while the base end sides are connected to each other. And a fifth bubble tube and a sixth bubble tube in which the liquid and the first bubble are sealed, and the fifth bubble tube and the sixth bubble tube are connected to the first bubble tube. And it is arranged symmetrically inside or outside the second bubble tube.

  In this invention, since the bubble moves more sensitively as the distance between the bubble tubes is larger, the distance between the first bubble tube and the second bubble tube is different from the distance between the fifth bubble tube and the sixth bubble tube. In one level, it is possible to measure the inclination state of the measurement surface with different sensitivities.

  Moreover, the level according to the present invention is the level, wherein the first bubble tube and the second bubble tube are arranged and placed on the measurement base, and the body base with respect to the reference plane And a measurement angle correction unit that adjusts the inclination angle.

  According to the present invention, the level of the base of the main body with respect to the reference plane can be adjusted, and measurement can be performed with higher accuracy.

  According to the present invention, it is possible to measure an inclined state without being affected by changes in the size of bubbles, thereby facilitating measurement work and reducing manufacturing costs.

It is a perspective view which shows the spirit level which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the effect | action of the level which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the measuring method by the spirit level which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the spirit level which concerns on the 2nd Embodiment of this invention. It is a principal part schematic diagram which shows the spirit level which concerns on the 3rd Embodiment of this invention. It is a principal part schematic diagram which shows the level which concerns on other embodiment of this invention.

(First embodiment)
A first embodiment according to the present invention will be described with reference to FIGS.
As shown in FIG. 1, the level 1 according to the present embodiment is placed on a measurement base 2 provided with a reference surface 2 </ b> A that is in contact with a measurement surface (not shown) and movably mounted on the measurement base 2. A main body base 3 and a bubble tube main body 5 placed on the main body base 3 are provided.

  The bubble tube main body 5 includes a first bubble tube main body 6 having a first bubble tube 6A and a second bubble tube 6B, and a third bubble tube 7A and a fourth bubble tube 7B. A second bubble tube body 7 having the same shape.

  The first bubble tube 6 </ b> A and the second bubble tube 6 </ b> B are formed as a pair, the liquid 8 and one first bubble 10 are sealed inside, and the base end sides of the first bubble tube 6 </ b> A and the second bubble tube 6 </ b> B are movably communicated with each other. While being connected, it is formed symmetrically with respect to the first central axis C <b> 1 and placed on the main body base 3. The distal ends of the first bubble tube 6A and the second bubble tube 6B extend substantially parallel to the first central axis C1.

  The third bubble tube 7 </ b> A and the fourth bubble tube 7 </ b> B are formed in a pair and enclose therein a liquid 8 and one second bubble 11 having substantially the same size as the first bubble 10. The proximal ends of the second bubbles 11 are connected so as to be movable, and are formed symmetrically with respect to the second central axis C <b> 2 and placed on the main body base 3. The distal ends of the third bubble tube 7A and the fourth bubble tube 7B extend substantially parallel to the second central axis C2.

  The first bubble tube main body 6 and the second bubble tube main body 7 are the proximal end sides of the first bubble tube 6A and the second bubble tube 6B, and the proximal end sides of the third bubble tube 7A and the fourth bubble tube 7B. Are arranged in pairs so that the first central axis C1 and the second central axis C2 are arranged on the same virtual plane (not shown) orthogonal to the reference plane 2A. Yes.

  Here, the base end sides of the first bubble tube 6A and the second bubble tube 6B, and the third bubble tube 7A and the fourth bubble tube 7B are in a direction away from the reference plane 2A than the respective distal ends. Inclined at a predetermined sensitivity setting angle α.

The measurement base 2 is provided with a sensitivity setting angle zero adjustment unit (sensitivity adjustment unit) 12 that varies a sensitivity setting angle that is an inclination angle of the first central axis C1 and the second central axis C2 with respect to the reference plane 2A . The main body base 3 is provided with a measurement angle zero correction unit (measurement angle correction unit) 13 for adjusting the inclination angle of the main body base 3 with respect to the reference surface 2A.

  The first bubble tube body 6 includes a reference scale (scale) 15 and a plurality of measurement scales (scales) 15 </ b> A arranged at regular intervals with respect to the reference scale 15 in the movement region of the bubble end of the first bubble 10. One scale part (scale part) 16 is arranged to be movable with respect to the first bubble tube 6A and the second bubble tube 6B. Further, in the second bubble tube main body 7 in the movement region of the bubble end of the second bubble 11, a plurality of measurement scales arranged at regular intervals with respect to the reference scale 15 and the reference scale 15 in the same manner as the first scale portion 16. A second scale portion 17 having 15A is arranged to be movable with respect to the third bubble tube 7A and the fourth bubble tube 7B.

Next, the operation of the level 1 according to the present embodiment will be described with further reference to FIGS.
First, as a measurement preparation, the sensitivity setting angle zero adjustment unit 12 is operated, the difference amount of the bubble end of the first bubble 10 with respect to the first bubble tube 6A and the second bubble tube 6B, the third bubble tube 7A and the fourth bubble tube 6B. The difference amount at the bubble end of the second bubble 11 with respect to the bubble tube 7B is made to coincide. As a result, the sensitivity setting angle α is an angle from the horizontal plane, and is the sensitivity setting angle set at the time of measurement.

  Here, the difference amount between the bubble ends of the first bubbles 10 of the first bubble tube main body 6 and the difference amount of the bubble ends of the second bubbles 11 of the second bubble tube main body 7 by the correction operation by the sensitivity setting angle zero adjustment unit 12. If the difference between and becomes larger, the direction of the measurement base 2 is changed by 180 degrees. Then, the sensitivity setting angle zero adjustment unit 12 is operated again so that the difference amounts coincide.

  Next, even if the orientation of the main body base 3 with respect to the measurement base 2 is changed by 180 degrees, the difference between the bubble ends of the first bubbles 10 of the first bubble tube main body 6 and the second bubbles 11 of the second bubble tube main body 7 are changed. The measurement angle zero correction unit 13 is operated so that the difference amount at the bubble end is the same. As a result, the angle with respect to the measurement angle of the main body base 3 itself is corrected to zero.

  Here, since both the enclosed bubble and liquid move in each bubble tube, even if the size of the bubble is reduced due to a temperature change or the like, as shown in FIGS. The position of the bubble end is only translated in the upward direction in both the bubble tubes (that is, A> a in the drawing), and the difference amount at the bubble end does not change.

  On the other hand, during tilt measurement, the amount of bubble movement is proportional to the amount of tilt, and the absolute amount of bubble movement is determined solely by the sensitivity setting angle. That is, as shown in FIGS. 2C to 2D, the entire bubble moves upward in the figure, but the difference amount at the bubble end does not change (that is, B = b in the figure). That is, the amount of inclination can be accurately measured without being affected by the change in the size of bubbles due to the temperature.

  When reading the difference amount from the first graduation portion 16 and the second graduation portion 17 at the time of measurement, as shown in FIG. 3A, when both the bubble ends are positioned on the reference graduation 15 when horizontal, As shown in FIG. 3B, a difference D occurs at the bubble end. The amount of difference at this time is equivalent to 3 scales. On the other hand, as shown in FIG. 3 (c), even when both the bubble ends are not positioned on the reference scale 15 when horizontal, as shown in FIG. By moving the second scale portion 17 and aligning one bubble end with the reference scale 15, it is read that the amount of difference from the other bubble end is equal to 3 scales.

  Thus, for example, when the sensitivity setting angle is 1 degree, the inclination amount of 20/1000 is set as one division of the difference amount of the bubble edge, so that the difference between the inclination sensitivity per division and the position of the bubble edge is set. The absolute inclination can be measured from the quantity.

  According to the level 1, when the measurement surface (not shown) is inclined with respect to the horizontal surface (not shown), when the reference surface 2A is brought into contact with the measurement surface, the first bubble 10 is moved to the first bubble tube 6A and the first bubble tube 6A. The relative position between the bubble end on the first bubble tube 6A side and the bubble end on the second bubble tube 6B side is changed by moving inside the base end side of the two bubble tube 6B. At this time, by measuring the distance between the bubble ends by the first scale portion 16 and the second scale portion 17, the degree of inclination of the measurement surface with respect to the horizontal plane can be measured.

  Moreover, since not only the 1st bubble tube main body 6 but the 2nd bubble tube main body 7 is provided, the distance between each bubble end of 6A of 1st bubble tubes and the 2nd bubble tube 6B, 7A of 3rd bubble tubes, By measuring at a position where the distance between the bubble ends of the fourth bubble tube 7B is the same, the absolute amount of the inclination angle of the measurement surface (not shown) can be measured.

  In particular, the sensitivity is such that the base end sides of the first bubble tube 6A and the second bubble tube 6B and the base end sides of the third bubble tube 7A and the fourth bubble tube 7B are respectively separated from the reference surface 2A more than the tip side. Inclined by the set angle. Therefore, the first bubble 10 is always arranged on the proximal end side of the first bubble tube 6A and the second bubble tube 6B, and the second bubble 11 is always proximal to the third bubble tube 7A and the fourth bubble tube 7B. Will be distributed. Accordingly, the first bubble 10 and the second bubble 11 can be smoothly moved in the tube while being integrated.

  At this time, since the sensitivity setting angle zero adjustment unit 12 is provided, by changing the inclination angle with respect to the reference surface 2A, the contact area between the bubble and the inner wall of the bubble tube is changed to change the bubble movement sensitivity. Can do. For example, the larger the angle of inclination with respect to the reference surface 2A, the smaller the contact area between the bubble and the inner wall of the bubble tube, so the bubble movement sensitivity can be reduced.

  Moreover, since the 1st scale part 16 and the 2nd scale part 17 can move with respect to the 1st bubble tube main body 6 and the 2nd bubble tube main body 7, respectively, the 1st scale part 16 and the 2nd scale part 17 are moved. Thus, the bubble ends can always be on the scale, and the distance between the bubble ends can be measured more suitably.

  Further, since the measurement angle zero correction unit 13 is provided, the level of the main body base 3 with respect to the reference surface 2A can be adjusted, and measurement can be performed with higher accuracy.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the component similar to 1st Embodiment mentioned above, and description is abbreviate | omitted.
The difference between the second embodiment and the first embodiment is that the level 20 according to the present embodiment is different from the first bubble tube main body 6 and the second bubble tube main body of the level 1 according to the first embodiment. 7 is provided with a bubble tube main body 21 integrated with 7.

  That is, the base end sides of the third bubble tube 7A and the fourth bubble tube 7B are connected to and integrally connected to the base end sides of the first bubble tube 6A and the second bubble tube 6B. Two bubbles 11 are arranged as one bubble 22.

Next, the operation of the level 20 according to the present embodiment will be described.
The level 20 according to the present embodiment also performs measurement by the same operation as the level 1 according to the first embodiment. First, as a measurement preparation, the sensitivity setting angle zero adjustment unit 12 is operated, the difference amount between the bubble ends of one bubble 22 in the first bubble tube 6A and the second bubble tube 6B, the third bubble tube 7A and the second bubble tube 6A. The difference amount at the bubble end of one bubble 22 in the four-bubble tube 7B is made to coincide. As a result, the sensitivity setting angle α becomes an angle from the horizontal plane and becomes the set sensitivity setting angle.

  Here, if the difference in the amount of difference between the bubble ends of one bubble 22 is further increased by the correction operation by the sensitivity setting angle zero adjustment unit 12, the direction of the measurement base 2 is changed by 180 degrees. Then, the sensitivity setting angle zero adjustment unit 12 is operated again so that the difference amounts coincide.

  Next, even if the orientation of the main body base 3 with respect to the measurement base 2 is changed by 180 degrees, the zero measurement angle correction unit 13 is operated so that the difference amount between the bubble ends of one bubble 22 is the same. Thereby, the angle with respect to the measurement angle which the main body base 3 itself has is corrected. Thereafter, measurement is performed in the same manner as in the first embodiment, and the absolute inclination amount is measured.

  According to this level 20, since one bubble 22 is provided in the entire bubble tube main body 21, the first bubble tube main body 6, the second bubble tube main body 7, The manufacturing cost can be further suppressed.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the component similar to other embodiment mentioned above, and description is abbreviate | omitted.
The difference between the third embodiment and the second embodiment is that the bubble tube body 31 of the level 30 according to this embodiment includes the fifth bubble tube 31A and the sixth bubble tube 31B. It is.

  The fifth bubble tube 31A and the sixth bubble tube 31B are formed as a pair, and the base end sides of the fifth bubble tube 31A and the sixth bubble tube 31B are connected to the base end sides of the first bubble tube 6A and the second bubble tube 6B. The fifth bubble tube 31A and the sixth bubble tube 31B are arranged symmetrically inside the first bubble tube 6A and the second bubble tube 6B with respect to the first central axis C1, and are arranged in a single direction with the liquid 8. Bubbles 22 are enclosed. That is, the first bubble tube 6A and the first bubble tube 6A and the first bubble tube 6B and the first bubble tube 6A and the sixth bubble tube 31B are different from each other in distance to the first central axis C1. The two bubble tubes 6B, the fifth bubble tube 31A and the sixth bubble tube 31B are arranged in a comb shape.

Next, the operation and effect of the level 30 according to the present embodiment will be described.
The level 30 according to the present embodiment also performs measurement by the same operation as the level 20 according to the second embodiment. Here, the first bubble tube 6A and the second bubble tube 6B, the fifth bubble tube 31A and the sixth bubble tube 31B, the first bubble tube 6A and the fifth bubble tube 31A, and the second bubble tube 6B and the sixth bubble. The distance between the bubble tubes is different between the tube 31B and the tube 31B. At this time, since the bubbles move more sensitively as the distance between the bubble tubes is larger, the movement sensitivity of one bubble 22 is set separately between the bubble tubes. Therefore, it is possible to measure the inclination state of a measurement surface (not shown) with different sensitivities with one level 30.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, if only measuring whether or not the measurement surface is inclined with respect to the horizontal plane, only one of the first bubble tube main body 6 and the second bubble tube main body 7 may be provided. The zero adjustment unit 12 and the measurement angle zero correction unit 13 may be omitted.

  Further, since the absolute position of the bubble is not related to the inclination angle, each bubble tube does not need to be formed symmetrically, and the first bubble tube, the second bubble tube, the third bubble tube, and the fourth bubble. Each of the tube, the fifth bubble tube, and the sixth bubble tube may be formed in different shapes, and the sensitivity setting angles may be different from each other. Even in such a case, the inclination angle can be measured by measuring the difference amount between the bubble ends.

  Furthermore, each bubble tube does not need to be connected so as to be formed in a square shape as described in each embodiment, and as shown in FIG. 6A, the first bubble tube main body 41 of the level 40 is used. And the base end side of the 2nd bubble tube main body 42 may be connected in the curved state. In this case, it can be manufactured more easily than when it is bent at a substantially right angle in the middle.

  Moreover, as shown in FIG.6 (b), a spirit level provided with the 1st bubble tube main body 50 and the 2nd bubble tube main body 51 which the 1st bubble tube main body 41 and the 2nd bubble tube main body 42 of the spirit level 40 isolate | separated. 52 is also acceptable. In this case, since there is no connection part of bubble tube main bodies, it can manufacture more easily.

  6C, the first bubble tube 61A and the second bubble tube 61B in the first bubble tube main body 61 of the level 60, and the third bubble tube 62A in the second bubble tube main body 62 and The fourth bubble tube 62B may be formed so as to extend in a direction intersecting the first central axis C1 and the second central axis C2 at a constant angle γ from the connection portion on the base end side. In this case, it can be manufactured easily because there is no curved portion.

  Further, as shown in FIG. 6 (d), the first bubble tube 72A and the second bubble tube 72B of the bubble tube main body 71 of the level 70 and the second bubble tube 72B, as compared with the level 20 according to the second embodiment. The distal end sides of the three bubble tubes 73A and the fourth bubble tube 73B may be further bent and connected to each other. In this case, it can manufacture more easily than the level 20 which the front end side is spaced apart.

  Moreover, as shown in FIG.6 (e), the level 80 is the bubble tube main body 81 without the 3rd bubble tube 7A and the 4th bubble tube 7B of the level 30 which concerns on 3rd Embodiment, and one correction | amendment. And a sensitivity setting zero correction bubble tube (sensitivity adjusting unit) 83 in which bubbles 82 for operation are arranged. In this case, the sensitivity setting angle of the bubble tube main body 81 is adjusted by adjusting the position of the correction bubble 82 of the sensitivity setting zero correction bubble tube 83 by a sensitivity setting angle zero adjustment unit (not shown). According to the level 80, it is possible to reduce the size while having a plurality of sensitivities.

1, 20, 30, 40, 52, 60, 70, 80 Level 2 Measurement base 2A Reference plane 3 Main body base 6A, 61A, 72A First bubble tube 6B, 61B, 72B Second bubble tube 7A, 62A, 73A Three bubble tubes 7B, 62B, 73B Fourth bubble tube 8 Liquid 10 First bubble 11 Second bubble 12 Sensitivity setting angle zero adjustment unit (sensitivity adjustment unit)
13 Measurement angle zero correction unit (Measurement angle correction unit)
15 Reference scale (scale)
15A Measurement scale (scale)
16 First scale part (scale part)
17 Second scale part (scale part)
22 One bubble 31A Fifth bubble tube 31B Sixth bubble tube 83 Sensitivity setting zero correction bubble tube (sensitivity adjustment unit)

Claims (10)

A measurement base with a reference surface that is in contact with the measurement surface;
A first bubble tube which is formed in a pair and has a liquid and one first bubble enclosed therein, and is connected to the base end side so that the first bubble is movably communicated and placed on the measurement base And a second bubble tube,
Equipped with a,
The first bubble tube and the second bubble tube are arranged to be inclined with respect to the reference plane in a direction in which a base end side is separated from the reference plane rather than a distal end side,
The level according to claim 1, wherein the first bubble has a dimension extending from the first bubble tube to the second bubble tube . The level according to claim 1, further comprising a sensitivity adjusting unit that varies an inclination angle of the first bubble tube and the second bubble tube with respect to the reference plane.   The level according to claim 1 or 2, wherein the first bubble tube and the second bubble tube are formed symmetrically with respect to the first central axis.   2. A scale portion having a plurality of scales respectively arranged at regular intervals in a movement region of a bubble end of the first bubble in the first bubble tube and the second bubble tube. The level according to any one of 3 above.   The level according to claim 4, wherein the scale portion is arranged to be movable with respect to the first bubble tube and the second bubble tube. A third bubble tube which is formed in a pair and has a liquid and one second bubble enclosed therein and is connected to the base end side so that the second bubble is movably communicated and placed on the measurement base And a fourth bubble tube,
The proximal end sides of the first bubble tube and the second bubble tube and the proximal end sides of the third bubble tube and the fourth bubble tube are arranged to face each other. The level according to any one of 1 to 5. The base end sides of the third bubble tube and the fourth bubble tube are connected in communication with the base end sides of the first bubble tube and the second bubble tube,
The level according to claim 6, wherein the first bubble and the second bubble are arranged as one bubble.   The level according to claim 6 or 7, wherein the third bubble tube and the fourth bubble tube are formed symmetrically with respect to the second central axis. A pair of base end sides are connected in communication with each other, and are connected in communication with the base end sides of the first bubble tube and the second bubble tube, and the liquid and the first bubble are contained therein. Comprising a fifth bubble tube and a sixth bubble tube,
9. The fifth bubble tube and the sixth bubble tube are arranged inside or outside the first bubble tube and the second bubble tube, respectively. Spirit level. A main body base on which the first bubble tube and the second bubble tube are arranged and placed on the measurement base;
A measurement angle correction unit that adjusts an inclination angle of the main body base with respect to the reference surface;
The level according to any one of claims 1 to 9, characterized by comprising:

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