Table of Contents
Introduction of Micrometer
A micrometer is a precision measuring device used to make very fine measurements. It is also known as micrometer caliper.
It is available in metric and imperial units. Metric micrometers typically measure in 0.01 milimeters increments, while imperial versions measure in 0.001 inches.
The measurements they provide are more accurate than other gauges such as dial calipers and vernier calipers, but much depends on the diligence of the user.
Accuracy of Micrometer
- Micrometer accuracy is verified according to DIN 863.
- Reference temperature – 20°C according to DIN 863.
- Measuring force – The force exerted by the ratchet drive on the measuring surface should be 5-10 N.
Working Principal
Micrometer works on the screw and nut principle. A barrel-shaped structure, also called a thimble, can be rotated axially and is used to measure distance from an object.
The micrometer screw is attached to a thimble, which is a focused cylinder attached to the micrometer. The circumference of the thimble is divided into equal micrometer halves for accurate results. When the screw is adjusted by the nut in a circular motion, its axial movement corresponds to the pitch of the screw used in the particular micrometer.
The screw rotation angle is directly or indirectly correlated with the absolute value of the axial motion. A given axial motion can be amplified in the resulting circumferential direction using the actual diameter of the worm. By reducing the thread pitch, the axial value can be reduced and the accuracy can be increased. Specific types of micrometers are available depend on requirement.
Types of Micrometer
Normally three types of micrometers are used as listed below.
- Outside Micrometer
- Inside Micrometer
- Depth Micrometer
Lets know more about these micrometers in detail.
1. Outside Micrometer
An outside micrometer (or outsider micrometer) is used to measure the outer surface of a component. It provides accurate measurement of components and is a very common type of micrometer used in manufacturing.
2. Internal Micrometer
Internal micrometers are used to measure internal dimensions such as the inner diameter of holes and pipes.
3. Depth Micrometer
Depth Micrometer is used to measure the depth of holes, slots and steps. Comes with a variety of interchangeable rods with different lengths, so it can be used to measure different depths
Closing Thought
Micrometer is a very important device to measure very small distance. It gives very precise reading of small mechanical components.