Spirit level - how to use it
The scale value of the level is represented by angle (second) or slope, and its meaning is represented by the angle at which the bubble deviates by one grid, or by the height of the bubble offset by one grid on the inclined height of the work surface 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 take a reading after the bubble is stable. If it is necessary to measure the actual inclination value of length L, it can be calculated by the following formula.
The actual inclination value of the level = the nominal division value L and the number of deviation grids; for example: the nominal division is 0.02mm/m, L=200mm, and the deviation division is 2 divisions, then
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, and half of the difference between the two readings is the zero error, that is, = (a1-a2)/2 grid. If the zero error exceeds the allowable range, the zero mechanism needs to be adjusted, and the screw 1 can be adjusted repeatedly to meet the requirements.
