Chinese name: Level mbth: Level Usage: Measuring Small Angle Category: Instrument Application: Testing the temperature of various machine tools: 20 2℃ Category: Universal Level, Cylindrical Level and other fields: Features and classification, characteristics, main types, working principle, instrument inspection, appearance inspection, interaction of components, flatness of working face, zero position inspection, error verification, inspection and adjustment, instrument measurement. Level is a common measuring tool for measuring small angles. In machinery industry and instrument manufacturing, it is used to measure the inclination angle relative to horizontal position, the flatness and straightness of machine tool guide rail, the horizontal position and vertical position of equipment installation, etc. According to the different shapes of level, it can be divided into two types: frame level and ruler level. According to the fixing method of level, it can be divided into adjustable level and non-adjustable level. Level level is mainly used to check the straightness of guide rails of various machine tools and other types of equipment and the horizontal and vertical positions of equipment installation. It can also be used to measure the working face with small angle and V-groove, and can also measure the installation parallelism of cylindrical workpiece and the horizontal and vertical position of installation. Level meter is an indispensable precision measuring tool for measuring levelness and verticality in mechanical equipment installation. The main type of bubble level is a measuring instrument to check whether the installation surface or flat plate of the machine is horizontal and measure the inclination direction and angle. Its shape is made of high-grade steel. After precision machining, the base of the base must be flat. A longitudinal circular glass tube is installed in the center of the base surface, and a transverse small glass tube is attached to the left end. The tube is filled with ether or alcohol, leaving small bubbles, which are always at the highest point in the tube. On the glass tube, there are scales at both ends of the bubble. Usually, when the machine is installed in the factory, the sensitivity of the commonly used bubble level gauge is 0.0 1mm/m, 0.02mm/m, 0.04mm/m, 0.05mm/m, 0. 1mm/m, 0.3mm/m, 0.4mm/m, that is, the level gauge is placed in. If the sensitivity is 0.0 1 mm/m, it means that there is a height difference of 0.0 1 mm at both ends of the ruler or flat plate (equivalent to a difference of 2 seconds at both ends). When the height difference of 1 m is h mm, bubbles will have scale difference. The principle of bubble level is to use the characteristic that bubbles can always be kept in the highest position in the glass tube. For a certain inclination angle, it is necessary to increase the arc radius (r) in order to make bubbles move a lot (so-called good sensitivity). If the distance of each scale of the level is 2 mm and the sensitivity is 0.0 1 mm/m, the difference between the two ends of 1 m is 2 seconds. That is, the radius of the bubble tube is 206. 185 m, and the device is in the frame, so different sensitivities have different radii, which is not directly related to the length of the frame. When using the level gauge, check it first. First, put the liquid level gauge on the flat plate and read the scale size of the bubble. Then put the level gauge in the same position and read the scale size. If the readings are the same, the relationship between the base of the level gauge and the bubble tube is correct. Otherwise, it needs to be adjusted with a fine-tuning screw until the readings are completely consistent, and then the measurement can be carried out. If you want to check the accuracy of the level, you can use a known angle composed of sine ruler and gauge block. At the same time, if you want to measure a large tilt angle, you can also use it with a sine ruler and a level meter. As a substitute for the traditional bubble inclinometer, the new level is more widely used in road engineering, mechanical measurement, construction engineering, industrial platform, oil exploration, military industry, ships and other occasions that need downward inclination or level in gravity reference frame. According to the classification of materials, the grades can be divided into plastic grade and glass grade. The precision of plastic level is low, and that of glass level is high. High-precision liquid level meters with good quality in foreign markets, such as SOLA, Bosch, ECONS, EPOCH and RISUX. Well-known domestic brands include: Oriental Seiko, Great Wall, Hengrui, etc. . . Electronic level is used to measure the bed surface of high-precision machine tools, such as CNC lathes, milling machines, cutting machines and three-dimensional measuring beds. Its sensitivity is very high. If the left-right deviation of 25 scales can be used to calculate the measurement, the measured workpiece can only be measured within a certain tilt range. The main principles of electronic level are inductance and capacitance. According to the different measuring directions, it can also be divided into one-dimensional and two-dimensional electronic level. The measuring part of electronic level is mainly composed of shell, micrometer and electrode bubble sensor. The electronic bubble sensor is similar to the general level, but the structure is different. Induction principle of frame electronic level: When the base of the level is inclined due to the inclination of the measured workpiece, the voltage of the induction coil changes due to the movement of the pendulum inside the level. The measuring principle of capacitance level is that a circular pendulum is freely suspended on a thin line, and the pendulum is suspended without friction under the influence of gravity. There are electrodes on both sides of the pendulum, and the capacitance is equal when the gap is the same. If the level is affected by the workpiece to be measured, the capacitance is different when the distance between the two gaps changes, resulting in an angle difference. Working principle The level tube of the liquid level gauge is made of glass. The inner wall of the leveling tube is a curved surface with a certain radius of curvature, and the tube is filled with liquid. When the level is tilted, the bubbles in the leveling tube move to the rising end of the level, thus determining the position of the horizontal plane. The greater the radius of curvature of the inner wall of the leveling tube, the higher the resolution, and the smaller the radius of curvature, the lower the resolution, so the radius of curvature of the leveling tube determines the accuracy of the level. The level gauge is mainly used to check the flatness, straightness and verticality of various machine tools and workpieces and the horizontal position of equipment installation. Especially when measuring verticality, the magnetic level can be adsorbed on the vertical working surface without manual support, which reduces the labor intensity and avoids the measurement error brought by human thermal radiation to the level. The working principle of the level meter is that the bottom and side of the level meter are right-angled structures, with a length of 2000mm and an accuracy of (0.02-0.025) mm/m/m. If the user has special requirements, it can be customized separately. The zeroing structure of level is unique, compared with the conventional structure: 1. Zero adjustment is easy. 2. After adjustment, the zero position is not easy to change. As shown in figure 1. When the V-groove surface at the bottom of the level rotates five times around the main shaft, if the bubble moves, the requirements can be met by adjusting the screw 2, which has been adjusted at the factory and generally remains unchanged. The structure of the level varies according to the classification. Frame level is generally composed of level body, level, insulated handle, main level, cover plate and zero adjustment device. Ruler level generally consists of level body, cover plate, main level and zero adjustment device. Level is a measuring tool with level as measuring and reading element. The level is a sealed glass tube, and the longitudinal section of the inner surface is an arc surface with a certain radius of curvature. Liquid with small viscosity coefficient, such as alcohol, ether and their mixture, is filled in the glass tube of the liquid level gauge. The part without liquid is usually called liquid level bubble. There is a certain relationship between the curvature radius of the longitudinal section of the inner surface of the glass tube and the calibration value, and the inclination of the measured plane can be measured according to this relationship. The inspection of instrument inspection level must be carried out in accordance with the corresponding standards. The temperature of the inspection room should be 20 2℃, and the inspection should be carried out under the conditions of firmness, no vibration and far away from heat sources. Before inspection, all parts of the level must be scrubbed clean, and then the level should be placed on the metal plate in the inspection room for at least 3h. Visual inspection of level The working surface of the newly manufactured level shall be flat and smooth, and there shall be no defects such as sand holes, air holes, bumps, scratches and rust. No paint stripping, corrosion and obvious defects are allowed on the non-working surface. The level should be clean and transparent, and its scribed lines should be clear and uniform, and there should be no discoloration. The scribe line should be perpendicular to the axis of the level. On the non-working surface of the level gauge, the manufacturer's name, factory number and dividing value shall be marked. The main water level interacting with each part should be installed firmly, and the zero adjustment device should ensure convenient and reliable use. Bubbles should move smoothly, and there should be no visible jumping or stagnation. When the room temperature is 20℃, the bubble length should be equal to the distance between two long scale lines, and the deviation should not exceed 1 grid for the scale of 0.02 ~ 0.05 mm/m; The scale of 0.06 ~ 0.10mm/m shall not exceed 0.5 grid. The movement stability of bubbles and the length of bubbles should be tested on a level meter. The flatness of the level working face is not allowed to protrude on the working face, and its flatness should comply with the provisions of Table 6- 10-54. The working face length is150 ~ 200, 250 ~ 300, with flatness deviation.