Place your Etalon indicating micrometer in a micrometer stand so that you have both hands free to work.
When you close the spindle on the micrometer to read zero on the barrel (the zero on the barrel coincides with the zero on the sleeve), then the dial hand ought to be near zero on the indicator dial.
Set the micrometer spindle to your ideal measurement. Let's say you are making pieces that must be .5000" in diameter: set the micrometer spindle to .5000"
Now tighten the spindle using the lever (don't force the lever or attempt to over-tighten), so that the spindle no longer moves.
Retract the movable anvil (the one above the dial) by pressing the button on the left side of the micrometer. The movable anvil will open slightly so that the gap is a little larger than .5000" This will allow you to insert a piece to be measured.
To verify the accuracy of your setting, insert a master (such as a gage block) between the anvils, resting on the support (which you have adjusted to fit your piece). Release the button, and the anvil will close on the gage block. The hand on the dial should read somewhere near zero. Make sure the block is firmly seated (you may have to wiggle it a bit) and then set the dial so that the hand is exactly on zero. Use the setting knob on top of the dial to make this adjustment.
Repeat several times to make sure you always get zero on the dial.
Now insert your piece to be tested. If it's exactly .5000" in diameter, the hand will also point to zero. If the hand is off, then that's the amount of error in your diameter. If the hand is under by 3 graduations, then your diameter is under by that amount, etc. You are in effect making a comparison measurement.
Repeat this procedure with all the pieces to be tested. Every now and then, reinsert the gage block to make sure the settings haven't changed.
Of course, if you don't see any hand movement on the dial, then something's wrong and we'll have to take a look at it. See page 30 for information on how to get your Etalon micrometer repaired.