Foreword:Gages are tools used to measure objects of various sizes, shapes, and surface roughness. Proper use of gages can improve measurement accuracy and ensure product quality. Common gauges include tape measures, vernier calipers, micrometers, inner diameter dial gauges, surface roughness comparison blocks, universal angle rulers and depth gauges. When using the measuring tool, the following points should be noted:
1.Check whether the measuring tool is in good condition and whether the scale is clear before use.
2.Handle with care when using to avoid collisions and severe vibrations.
3.When measuring, make the gage fit closely with the object to be measured, but do not use too much force.
4.Keep your eye perpendicular to the gage scale when reading.
5.Clean up the stains on the measuring tool in time after use and keep it properly.
Note: See the end of this article for references.
First, the steel ruler.
The steel ruler is the simplest length gauge and is available in lengths of 150, 300, 500 and 1000 mm. Figure 1-1 shows a commonly used 150 mm steel ruler. The steel ruler is used to measure the length of the part (Fig. 1-2), and its measurement results are less accurate. This is due to the fact that the spacing of the cut lines of the steel ruler is 1mm, and the width of the cut line itself is 01～0.2mm, so the reading error is relatively large when measuring, and only the number of millimeters can be read, that is, its minimum reading value is 1mm, and the value smaller than 1mm can only be estimated.
Second, internal and external calipers.
Figure 1-3 shows two common types of internal and external calipers. Internal and external calipers are the simplest comparison gage. The outer caliper is used to measure the outer diameter and flat surface, and the inner caliper is used to measure the inner diameter and groove. None of them can directly read out the measurement results themselves, but take the measured length dimension (the diameter is also a length dimension) and read it on the steel ruler, or remove the required size from the steel ruler first, and then check whether the diameter of the part matches.
3. Feeler gauge. Feeler gauge is also known as thick gauge or gap piece. It is mainly used to inspect the gap between the two joint surfaces of the machine tool, such as the special fastening surface and the fastening surface, the piston and the cylinder, the piston ring groove and the piston ring, the crosshead slide plate and the guide plate, the top of the intake and exhaust valve and the rocker arm, and the gear meshing clearance. The feeler gauge is composed of many layers of thin steel sheets of different thicknesses (Figure 1-10), which are made one by one according to the group of feeler gauges, and each piece of each feeler gauge has two parallel measuring planes, and each piece has a thickness mark, which can be used in combination.
Fourth, vernier calipers.
Vernier caliper is a commonly used measuring tool, which has the characteristics of simple structure, easy to use, medium accuracy and large size range of measurement, etc., which can be used to measure the outer diameter, inner diameter, length, width, thickness, depth and hole spacing of parts, etc., with a wide range of applications.
5. Spiral measuring micrometer.
The measuring tool made by applying the principle of spiral micrometer is called a spiral micrometer. They have a higher measurement accuracy than vernier calipers and are more flexible in measurement, so they are often used when machining accuracy is required. Commonly used spiral reading quantities have a micrometer and a micrometer. The reading value of the micrometer is 001mm, the reading value of the micrometer is 0001mm。It is customary for factories to refer to the micrometer and micrometer collectively as the centrifle or centicard. At present, a large number of readings are used in the workshop to read the value of 001mm of the Minute Gauge.
Sixth, the level.
The spirit level is a common measuring tool for measuring the change of angle, which is mainly used to measure the horizontal position of the parts of each other and the flatness, straightness and verticality of the equipment installation, and can also measure the small inclination angle of the parts. Commonly used levels include strip level, frame level and digital optical level.
Reference: "How to Use Measuring Tools".
Word version with full table of contents! It covers almost all commonly used measuring tools, including structural composition and use methods, which is convenient for engineers and technicians to use!