ROK Tubular Inside Micrometer Specification and Usage

 

            This kind of micrometer can be long or short to measure different work piece Without buying different micrometers.  The sets come with extension rods and setting stardard.  An inside micrometer is a device designed to precisely measure things such as the inner diameter of holes. Where a standard micrometer might be used to measure the outer diameter of a bolt, an inside micrometer could be used to measure the inner diameter of a nut. There are several designs for the inside micrometer, though they all perform this same basic function. All micrometers are designed to make very precise measurements, but the micrometers themselves can be either small or quite large. Each inside micrometer will have both a minimum and maximum diameter it is able to measure, so its common to find inside micrometer sets.   When taking internal measurements, you may need to use an extension rod if the measuring capacity of your micrometer is not great enough. To select the correct extension rod, insert each of the rods provided with your micrometer into the instrument and hold them inside the space to be measured. otate thimble
Turn the thimble using the  ratchet speeder until the spindle is close to the object. As you approach the edge of the hole, pivot the micrometer, keeping it square. Continue turning until the spindle stops rotating. The blade micrometer ratchet will keep turning, applying the correct amount of force for an accurate measurement. Using the thimble alone requires a degree of skill and practice to achieve the correct "feel".

           The unique feature of inside micrometers is their ability not only to measure small diameters and other distances very accurately, but also to measure very large diameters and distances accurately. To this end, inside micrometers may be found in many sizes. There are also sets that include a single measurement head and a number of tubes in varying lengths that can be attached to the head. This type of set can be used to measure a wide variety of inside diameters and various parallel surfaces without the need for multiple micrometers.