A Micrometer is an instrument used to measure thickness very accurately. It was originally purchased by Chorca to assist the 3D printer members in tuning their printer by allowing them to accurately measure the width of the extrusion.
The tool is very useful if you want to measure thin things that otherwise would be very difficult or impossible to measure with calipers. Things such as the thickness of paper, a hair, foil, wire, etc.
Caution: Take extra care when using it as it is a very precise instrument. Dropping or forcing it will cause it to lose calibration. Only use the small knob at the end to open or close the jaws.
Take the micrometer out of the case. Use the micrometer over a bench at all times to prevent dropping it on the floor. Hold the large part in one hand, turn it on by pressing the On/Off/0 button once. The display will come on. Using the knob at the far back of the micrometer (the small one) tighten the jaws until the knob starts to click (clockwise). Press the On/Off/0 button once. This will zero the reading. Now, using the small knob still, turn it counterclockwise to open the jaws as wide as you need, then have a helper insert the piece to be measured into the jaws. Slowly (using the SMALL KNOB) turn clockwise to tighten the jaws until the knob clicks. The readout on the display is the thickness of the material.
Before putting the micrometer away, close down the jaws ALMOST all the way, do not fully tighten them. Turn the unit off by pressing and holding the On/Off/0 button until the screen shuts off.