The micrometer caliper is an end-measuring instrument for use in measuring outside dimensions. Although the mike is fairly easy to apply, the accuracy it gives depend upon the application of the proper amount of torque to the thimble . Too much torque is likely to spring the frame and cause error . Thus it is important that personnel using these instruments be trained in their use , and also that they be periodically required to check their measurements against a standard to minimize errors. The indicator to provide a positive indication of measuring pressure applied. The instrument can be used like an indicating snap gage.
A standard metric micrometer is limited to a range of 25mm (1 in. for a micrometer reading in inch units). Thus different micrometers are needed to measure a wide range of dimensions.