Micrometer Parts and Their Main Function:
As we know the micrometer has wide application in all fields of science during different scientific experiments and in engineering to measure the values of finest objects up to higher precision and accuracy.
So for better understanding and to ensure the appropriate use of micrometer, first we must have to know its mechanism and basic parts, construction and main function.
So we discuss here all the basic parts of micrometer and the main function of these parts in order to make proper use and avoid measurement errors. The typical micrometer that’s used normally, is called outside micrometer so following are its parts.
It’s a c shaped frame as identified in the picture, is a rigid part that has both holding points for a job or object to be measured. Its size depends on micrometer measuring range so size of c frame increases as range expands to bigger.
Its main function is to provide basic structure of a micrometer in which stationary anvil located at one end and movable spindle slides inward or outward trough other end of c frame.
Zero adjust screw:
It’s a screw located back end of anvil shown in figure. As name shows it is to correct or adjust the zero error of micrometer if there is some error found before the measurement during test.
As discussed above it is a small stationary cylindrical part of micrometer located in far end of c-frame and acts as one holding point for measuring objects. So we can say it’s a one of rigid measuring and holding point of micrometer.
A cylindrical long part which is mounted through all other parts sleeve, lock nut and thimble. It is moveable part and has a connection with ratchet as we rotate the ratchet clockwise or counter clockwise the spindle slides out or inward to adjust it with compare to measuring object size.
Anvil Face and Spindle Face:
Faces of both anvil and spindle which are opposite to each other are the measuring points of micrometer and hold the measuring object collectively.
As we know the mechanism of micrometer based on precision ground threads of spindle so the lock nut works as stationary nut for this mechanism, so rotation of this mechanism into lock nut controls the spindle movement.
It’s a barrel type cylindrical part which mounted on spindle and is main scale of micrometer because main scale is engraved on the sleeve .Thimble rotates around that sleeve and spindle. Its main function is indication of reading in millimeter in case of imperial micrometer.
Thimble is also mounted on spindle and a scale is engraved around it perimeter of thimble. Scale of thimble is to show the measurement value in fraction.
It’s a knurled thumb gripe to rotate the spindle into desired direction for measuring process, provided with ratchet action to avoid over tightening of micrometer across the measuring object and also ensures equal pressure force of each measurement.
Here are some specific parts those are associated with different Types of micrometers.
Digital reading display:
Its a specific part to digital micrometers only, where it displays the measured value directly in digits.The unique feature is its a analog display in terms of mechanism yet called digital because of its number roller system display , same like there was analog fueling machine display in old days petrol pumps and bikes speedometer mileage counter.
Electronic reading display(LCD):
It comes with noways micrometer, mounted on measuring end of its c-frame.
It has made measuring process very easy and accurate because errors due to human readings are eliminated and no need of time taking calculations too. So its very handy to have and use electronic display digital micrometers.
Dial for circular scale:
A dial is provided with bench type micrometer normally to indicate its circular scale reading. Some other micrometre’s types do have dial reading indication facility for their circular scales depending upon their applications.