The use method and type of the spirit level
How to use the level
The scale value of the level is expressed by angle (second) or slope, and its meaning is expressed by the angle at which the bubble is offset by one grid, or the height of the working surface that is offset by one grid on a length of one meter.
Since the inclination angle of the level is very small, tg, such as tg4 4 radians=0.02mm/1000mm, when measuring, make the working surface of the level close to the surface to be measured, and read after the bubbles are stable.
If you need to measure the actual inclination value with a length of L, you can use the following formula to calculate the actual inclination value of the level instrument = the number of deviation grids of the nominal division value L; for example: the nominal division value is 0.02mm/m, L=200mm, the deviation If the number of grids is 2 grids, the actual tilt value=0.02/1000 200 2=0.008mm.
In order to avoid measurement errors caused by the inaccurate zero position of the level meter, the zero position of the level meter must be checked or adjusted before use.
The method of checking and adjusting the zero position of the level is to place the level to be calibrated on a roughly horizontal plate, close to the positioning block, and after the bubble is stable, take the reading at one end of the bubble as a1, then turn the level 180 degrees, and place it in the original position accurately. According to one side of the first reading, write down the reading at the other end of the bubble as a2,
Half of the difference between the two readings is the zero position error, that is, =(a1-a2)/2 divisions. If the zero error exceeds the allowable range, the zero mechanism needs to be adjusted
main type
bubble level
The bubble level is a measuring instrument to check whether the machine installation surface or plate is level, and to measure the direction and angle of inclination. Its shape is made of steel. There are long and curved glass tubes, and there are also small horizontal glass tubes attached to the left end. The tubes are filled with ether or alcohol, and there is a small bubble, which is always at the highest point in the tube. There are scales on both ends of the bubble on the glass cylinder. Usually, when the machine is installed in the factory, the sensitivity of the commonly used bubble level is 0.01mm/m, 0.02mm/m, 0.04mm/m, 0.05mm/m, 0.1mm/m, 0.3mm/m and 0.4mm/m, etc. That is, place the level on a 1-meter-long straight rule or plate. When one of the endpoints has a sensitivity indicating the difference in size, if the sensitivity is 0.01 mm/m, it means that there is a difference of 0.01 mm between the two ends of the straight rule or plate. The difference in height (equivalent to a difference of 2 seconds between the two ends), when there is a height difference of h mm in length of 1 m, the bubble will have a difference of one scale. The principle of the bubble level is to use the bubble in the glass tube, and the bubble can always be kept at the highest position.
electronic level
Electronic level, it is used to measure high-precision machine tool, such as NC lathe, milling machine, cutting machine, three-dimensional measuring bed and other bed surfaces, its sensitivity is very high, if it can be calculated by shifting 25 scales left and right during measurement, the measurement The workpiece can only be measured within a certain range of inclination. There are two main principles of electronic levels: inductive and capacitive. According to different measurement directions, it can also be divided into one-dimensional and two-dimensional electronic levels.
