In our earlier blogs we have spoken about micrometers and Abbe’s principles, to know more about how to use a micrometer please see the following video:
How to use an adjustable micrometer?
To illustrate how an adjustable micrometer can be used, we shall use the Mitutoyo 104-135A model which has a measuring range of 0 – 150 mm. The micrometer is designed for fast, easy, and precision measuring of large components which have dimensions above 100 mm.
It may be noted that it is impossible to check zero reading by bringing the two measuring faces into contact. When we look into the parts of the adjustable micrometer, generally five standards varying in length in step of 25 mm is provided. All these rods are provided with ebonite pads in order to prevent the transfer of heat from operator’s hand.
We have used a Jafuji micrometer stand to mount the micrometer.
Before using a micrometer wipe off any oil or dust from the measuring face, anvil, and the master setting rod with a soft lint free cloth.
To verify that the micrometer is read correctly, the setting rods are provided. Do not set the nominal value which is on the micrometer setting standards, instead set the calibrated value which is in the certificate.
While fixing the interchangeable anvils make sure that both slots meet each other and tighten the anvil properly using the screw heads.
How to measure a 10 mm component?
- Use a constant force device like a ratchet to apply a constant measuring force
- The thimble scale can be read directly to 10 microns but may be estimated to 1 micron when the lines are coincident because the line thickness is 1/5th of the spacing between them.
- While measuring make sure that the fiducial line is parallel to the eye level, if not, it will lead to parallax error.
- Avoid sudden temperature variation of the micrometer, leave it in a room for sufficient time to adjust to the room temperature.
- The micrometer should be fitted correctly into the stand.
For a step-by-step video on how to use an adjustable micrometer please watch the following video:
