 Welcome to Calibrating a Depth Micrometer. In this video, you'll review the steps for calibrating the length of depth micrometer measuring rods. The depth micrometer extends its range with measuring rods. A typical set measures from 0 to 6 inches using 6 measuring rods, each with a 1 inch range. To change a measuring rod, unscrew the thimble cap and switch to a new rod, removing all dirt or chips as you seat the rod into the thimble. Every time you change a rod, make it a steadfast rule to recalibrate the depth mic against a surface plate or a gauge block. Holding the base down firmly, advance the rod just until it touches the surface plate, but not so much that it moves the instrument up. If you do find that the depth micrometer doesn't zero out, change the length of the rod via its adjusting nut. Clamp the rod in soft jaws in a small vise so it won't bend when you adjust the length. With the small spanner wrench, back the nut off one half turn and then turn it forward again to its new length. Admittedly, this trial and error process can be frustrating. That's the process of recalibrating depth micrometer measuring rods. Congratulations! You have completed the video Calibrating a Depth Micrometer. Thank you for watching. If you liked this video, give us a thumbs up.