Characteristics and classification of level meters


Published:

2023-03-03

The level gauge is a commonly used measuring tool for measuring small angles. In the mechanical industry and instrument manufacturing, it is used to measure the inclination angle relative to the horizontal position, the flatness and straightness of machine tool equipment guide rails, and the horizontal and vertical positions of equipment installation. According to the different appearance of the level, it can be divided into two types: frame level and ruler level; According to the fixing method of the level, it can be divided into adjustable level and non adjustable level.

Characteristics and classification of level meters

characteristic

The level gauge is a commonly used measuring tool for measuring small angles. In the mechanical industry and instrument manufacturing, it is used to measure the inclination angle relative to the horizontal position, the flatness and straightness of machine tool equipment guide rails, and the horizontal and vertical positions of equipment installation. According to the different appearance of the level, it can be divided into two types: frame level and ruler level; According to the fixing method of the level, it can be divided into adjustable level and non adjustable level.

The level gauge is mainly used to inspect the straightness of various machine tools and other types of equipment guide rails, as well as the horizontal and vertical positions of equipment installation. It can also be used for small angle measurements and working surfaces with V-grooves. It can also measure the installation parallelism of cylindrical workpieces, as well as the horizontal and vertical positions of installation. The level gauge is an indispensable precision measuring tool for measuring the levelness and perpendicularity of mechanical equipment installation.

Main types

The bubble level is a measuring instrument that checks whether the mounting surface or flat plate of the machine is horizontal, and measures the inclination direction and angle. Its appearance is made of steel. After precise processing, the base of the frame should be flat, and a glass tube with a longitudinal and circular shape is installed in the middle of the seat surface. There are also small horizontal glass tubes attached to the left end. The tube is filled with ether or alcohol, and there is a small bubble left, which is always at the apex in the tube. The glass cylinder has graduated lines at both ends of the bubble. Generally, when installing a machine in a factory, the sensitivity of commonly used bubble level gauges is 0.01mm/m, 0.02mm/m, 0.04mm/m, 0.05mm/m, 0.1mm/m, 0.3mm/m, and 0.4mm/m, which means that the level gauge is placed on a 1m long straight gauge or flat plate. When there is a difference in the sensitivity indication at one end, such as a sensitivity of 0.01 mm/m, it means that there is a height difference of 0.01 mm between the two ends of the straight gauge or flat plate (equivalent to a difference of 2 seconds between the two ends), When there is a height difference of h mm for a 1 m long bubble, there will be a scale difference. The principle of a bubble level meter is to utilize the characteristics of air bubbles inside a glass tube, which can often be kept at a high position.

For a specific tilt angle, if you want to make the bubble move a large amount (i.e., with good sensitivity), you need to increase the arc radius (R). If the distance between each scale of the level is 2 mm and the sensitivity is 0.01 mm/m, the difference between the two ends of the equivalent 1 m is 2 seconds. That is, the bubble tube has a radius of 206.185 meters, and the device is installed within the frame. Different sensitivities have different radii, which are not directly related to the length of the frame.

When using a level gauge, check it first. First, place the level gauge on a flat plate, read the scale size of the bubble, then invert the level gauge to the same position, and then read its scale size. If the readings are the same, it indicates that the relationship between the level gauge base and the bubble tube is correct. Otherwise, it is necessary to adjust with a fine adjustment screw until the readings are the same before measuring. If you want to check the accuracy of the level, you can use a known angular size consisting of a sinusoidal rod and a gauge block. At the same time, if you want to measure a large inclination angle, you can also use it together with a sinusoidal rod and a level gauge.

As an alternative to traditional bubble type inclinometers, the new level is more widely used in road engineering, mechanical surveying, construction engineering, industrial platforms, petroleum exploration, military industry, ships, and other situations where the inclination or level under the gravity reference system is required.

According to material classification, the level can be divided into plastic level and glass level. The accuracy of the plastic level is low, while the accuracy of the glass level is relatively high.

Electronic level gauge is used to measure the surface of high-precision tool machines, such as NC lathes, milling machines, cutting machines, and three-dimensional measuring machines. Its sensitivity is very high. If measured with a left to right offset of 25 scales, the measured workpiece can only be measured within a specific tilt range. The main principles of an electronic level are inductive and capacitive. According to different measurement directions, it can also be divided into one and two dimensional electronic level meters. The measurement part of the electronic level is mainly composed of a housing, a micrometer device, and an electrode bubble type sensor. The electronic bubble type sensor has a similar function to the level of a general level gauge, but its structure is different.

Inductive principle: When the base of the level meter is tilted due to the inclination of the workpiece to be measured, the movement of the internal pendulum causes the voltage change of the induction coil. The measuring principle of a capacitive level meter is that a circular pendulum is freely suspended on a thin line, and the pendulum is affected by the gravity of the earth's center, and is suspended in a frictionless condition. "There are electrodes on both sides of the pendulum and the capacitance is equal when the gaps are the same. If the level gauge is affected by the workpiece to be measured, changes in the distance between the two gaps will result in differences in capacitance and angle.".