Question

in the micrometer screw gauge used for measurement of inner diameter of tube

Answer 1

For circular tubes under, say, 1″, you might use a pin gauge set. Above that an inside micrometer will produce more accurate/repeatable results than a calipers, in the hands of an average user. The calipers will still get you to the right tube/pipe size, just not as repeatable. Another technique is to use pi-tape to measure the OD, and calipers to determine the wall thickness. This can be quite good enough for larger specimens.