How to use the micrometer screw (the structure of the micrometer)

The structure of micrometer

The micrometer screw, also known as a micrometer, is a more precise length measuring instrument than a vernier caliper, with an accuracy of 0.01-0.001mm. It is often used to measure the diameter of filaments and small balls and the thickness of thin sheets.

Micrometer screw How to use
When using a micrometer screw to measure the length of an object, first withdraw the micrometer screw and place the object to be measured between the two measuring surfaces. There is a ratchet handle at the tail end of the micrometer screw. Turning it can move the measuring rod. When the pressure between the measuring rod and the object to be measured (or the anvil) reaches a certain value, the ratchet will slide and produce a click, click sound, the movable sleeve will no longer rotate, and the measuring rod will also stop moving forward. At this time, the reading can be taken. When reading, read the part above 0.5mm from the main scale, read the remaining decimal part from the differential cylinder [estimated to one tenth of the minimum graduation value, that is, (1/1000)], and then add the two together. For example, the reading of Figure 1-6 (a) is 5.155mm, and the reading of (b) is 5.655mm.

When using a micrometer, you should pay attention to the following issues:
1. Check the zero point reading before measurement and make a zero point correction to the measured data.

2. When checking the zero reading and measuring the length, do not turn the micrometer screw and differential cylinder directly, but turn the ratchet handle gently. 3. After the measurement, there should be a gap between the anvil and the micrometer screw to avoid damage to the thread due to thermal expansion.