No manuals for your model here?
www.mitutoyo.pt
I don't own a digital micronometer but other digital measuring devices I've used that have the abs/Inc feature work as follows. A long press and hold of abs button will set the "absolute" position at 0.000 as in when the micronmeter is closed. A short push of the Inc button will reset the readout out to 0.000 and that gives you "incremental" readings from wherever the point you started from and independent form the absolute position.
That isn't the north America web site. To download files there, I have to make an account at Mitutoyo and it won't let me open that account because I already have a Canada account. The Canada and US sites don't seem to have the downloads.
That said, your suggested methods were most helpful. I tried various varients of your suggestions to see what I could accomplish.
Merely toggling the Abs/Inc button always sets the measurement to 0.00000. Further presses do nothing except maintain that temporary zero. If the measure is changed from that, the Abs/Inc button sets that new point to zero. In other words, a short single press of the Abs/Inc button ALWAYS sets the mic to zero in Incremental mode.
The only way to return to the original setting is to press and hold the Abs/Inc button.
However, pressing and holding the Abs/Inc button does not set the Absolute position to zero. It merely returns the display to whatever the measurement would have been if the Inc button had never been pushed.
In other words, pressing and holding Abs/Inc seems to exit Incremental mode and return to the normal mode.
To actually zero the Micrometer, it looks like you use the Preset button. To change the zero for the absolute position, you press and hold the Preset button until a small P starts flashing in the top right corner. The Micrometer will stop changing as the drum is turned and stays on 0.00000. A single press of the Preset button while the P is flashing zeros the Micrometer and turns off the flashing P. This then becomes the new Absolute position.
Thanks so much for your suggestions. They were most helpful and I think I am all set now.