Relevant points for attention when measuring with a level meter
1. The two V-shaped measuring surfaces of the spirit level are the benchmarks of measuring accuracy, and should not be in contact with or rubbed against the rough surface of the work during measurement. It must be placed with care to avoid damage to the level due to scratches on the measurement surface and cause undue measurement errors. 2. When using a level to measure the vertical surface of the workpiece, do not hold the part opposite to the auxiliary side, but push hard to the vertical plane of the workpiece, which will affect the accuracy of the measurement due to the force deformation of the level. The correct measurement method is to hold the inner side of the auxiliary measuring surface with your hand, make the level stick to the vertical plane of the workpiece stably and vertically (adjust the bubble to the middle position), and then read the number of cells moved by the bubble from the vertical level.
3. When using a spirit level, ensure that the working surface of the spirit level and the surface of the workpiece are clean to prevent dirt from affecting the accuracy of the measurement. When measuring the horizontal plane, at the same measuring position, the level should be adjusted in the opposite direction before measuring. When moving the level, the working surface of the level is not allowed to rub against the surface of the workpiece, and it should be lifted and placed.
4. When measuring a workpiece with a large length, the workpiece can be divided into several size segments on average, and the segment measurement method is used. Then, according to the measurement readings of each segment, an error coordinate diagram is drawn to determine the maximum number of grids of the error. When inspecting the straightness of the bed guide rail in the longitudinal vertical plane, place the frame level on the tool rest close to the front guide rail, and move the tool rest from left to right starting from the limit position where the tool rest is at one end of the headstock. The secondary moving distance should be approximately equal to the border ruler of the spirit level (200mm). Record the readings of the spirit level when the tool holder is at each measuring length position in turn. Arrange these readings in sequence, and draw the straightness error curve of the guide rail in the vertical plane with an appropriate scale. The reading of the level meter is the ordinate. The reading of the level meter when the tool holder is at the initial position is the starting point, and a broken line segment is made from the origin of the coordinates. After each reading, the end point of the previous broken line segment is used as the starting point to draw the line segment that should be broken. The curve composed of line segments is the straightness curve of the guide rail in the vertical plane. The maximum coordinate value of the curve relative to the connecting line at both ends is the straightness error of the full length of the guide rail, and the difference in coordinates between the two ends of the curve relative to the two ends of the curve within any local measurement length is the local error of the guide rail.
5. The flatness inspection method of the worktable of the machine tool, the worktable and the saddle are respectively placed in the middle of the stroke, a bridge is placed on the worktable, a level is placed on it, and the bridge is moved along the measurement directions shown in the figure, each Record the level reading once for the bridge span d. The reference plane is established by the three points A, B, and D on the worktable, and the coordinate values of the planes of each measuring point are obtained according to the readings of the level instrument.
6. When measuring the verticality of large parts, use a spirit level to roughly adjust the reference surface to level. On the reference surface and the surface to be measured, measure step by step with a level meter and determine the reference orientation by graphic method, and then calculate the verticality error of the measured surface relative to the reference.
When measuring small parts, first place the level on the reference surface, read the value at one end of the bubble, and then use one side of the level to stick to the vertical surface to be measured. If the bubble deviates from the first (reference surface) reading value, it is the measured surface verticality error.
