VIDEO: Digital Micrometer Use from Mitutoyo

I'm Dan Ben Hart, Product Support Specialist from Mitutoyo America Corporation. In this video, we’ll describe the use of a digital micrometer.

With lint-free paper, wipe any dust from the micrometer. Place a piece of paper between the measuring faces of the micrometer and lightly close them. Without opening the jaws, pull the paper out from between the measuring faces; this will ensure that both of them are free from dust and oil. Once the micrometer is clean, you can set the origin. Close the measuring faces by rotating the thimble using the ratchet stop, friction thimble, or ratchet thimble. Pay close attention to the speed and amount of force used when closing the faces, since this should be the same for every measurement. With measuring faces closed, lock the spindle in place using the spindle clamp. Press and hold the origin button until the display reads zero. You should also check the origin over the course of the day, this is because thermal expansion of the frame can cause the micrometer to give incorrect readings.

Micrometers are typically used in two ways: held in the operator's hand and held by a micrometer stand. Handheld is often viewed as being more convenient and is required in situations when the item to be measured cannot be brought to a measuring station. However, holding the micrometer in your hand introduces more potential sources of error as well as causing the frame to expand as the heat from your hand transfers to the micrometer frame. Micrometer stands provide a stable base and allow the operator to give their full attention to the alignment of the workpiece and to measuring force consistency. Measuring stands also separate the operator from the frame minimizing thermal expansion.

For demonstration purposes, we will use a micrometer stand open the measuring faces to allow ample clearance of the workpiece. With the workpiece situated close the measuring faces until just before they make contact. Using the ratchet stop, friction thimble, or ratchet thimble apply the same amount of force is used when setting the origin. Lock the spindle using a spindle clamp to prevent the spindle from turning while reading the display.