Before using your micrometer, It is important to check that it is properly zeroed to ensure that your measurements are accurate and reliable.
This means that when both the anvil and spindle measuring surfaces of the micrometer are closed together, the scales will read zero.
The sleeve of the micrometer is adjustable, allowing you to line up the index line with the zero (0) on the thimble.
Before checking the zero position, ensure that the measuring surfaces are clean and free from defect.
Zeroing the micrometer uitilises the same proceedure as when measuring.
To check the zero position, rotate the thimble using the micrometer ratchet speeder until the spindle is close to the anvil.
Carefully turn the ratchet as you approach the anvil and continue turning until the spindle stops rotating. The ratchet will continue to turn, applying the correct amount of force for an accurate measurement of the zero position.
Using the micrometer thimble alone requires a degree of skill and practice to achieve the correct “feel”.
Then check that the zero (0) on the thimble lines up with the index line on the sleeve.
Check several times, by repeatedly backing off the spindle and then re-checking the zero. If the Zero lines up repeatedly, then your micrometer is ready for use.
If the zero fails to line up with the index line, the micrometer will need to be re-zeroed using the adjusting spanner usually provided with the instrument.With the two measuring faces in their correctly zeroed position, use the locking device to lock the spindle so that nothing moves.
Locate the hook of the supplied spanner into the hole at the base of the sleeve. Carefully turn the sleeve until the index line aligns with the zero.
Unlock the spindle then repeat the zeroing procedure until the zero repeatedly lines up with the index line.