The difference between spirit level, bubble level and electronic spirit level
Levels: Levels are used to measure small angles. They are often used to check and adjust the horizontal or vertical position of machines or parts in the production process, and then to check the straightness or flatness of machines or parts. At present, there are two types of bubble level or electronic level commonly used in the industry. The latter can be connected to a personal computer through an RS-232 adapter card, which is very convenient.
1. Sprit levels
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 to place the level meter on a 1 m long straight rule or plate. When one of the end points has a sensitivity indicating the difference in size, if the sensitivity is 0.01 mm/m, it means that the two ends of the straight rule or plate have a difference of 0.01 mm. The difference in height (equivalent to a difference of 2 seconds between the two ends), when there is a height difference of hmm in the 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
For a certain inclination angle, if you want to increase the movement of the bubble (that is, the so-called good sensitivity), you need to increase the arc radius (R). If the distance per scale of the level meter is 2 mm and the sensitivity is 0.01 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 meters, and it is installed in the frame. Different sensitivities have different radii, and there is no direct relationship with the length of the frame.
When using a level, you should check first. Put the level on the flat plate and read the scale of the bubble, then turn the level upside down and place it in the same position, and then read the scale. If the readings are the same, it means that the base of the level is connected to the bubble tube. The relationship between is correct. Otherwise, it is necessary to use the fine-tuning screw to adjust until the readings are exactly the same before making the measurement. If you want to check the accuracy of the level, you can use the known angle size composed of the sine rod and the gauge block. At the same time, if you want to measure a large inclination angle, you can also use it together with a sine rod and a level.
2. Electronic levels
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. Inductive principle: when the base of the level is tilted due to the tilt of the workpiece to be measured, the voltage of the induction coil caused by the movement of the pendulum inside the level changes. The measurement principle of the capacitive level is that a circular pendulum hangs freely on a thin wire. The pendulum is affected by the gravity of the center of the earth and is suspended in a friction-free state. 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 different distances between the two gaps will produce different capacitances and angle differences.
