I just got a LCD Height Gauge (iGaging) for Christmas.

I have no problem using it. It can be reset to zero at any one time.

One of the function key is ABS: absolute measuring and incremental.

Press ABS key to get relative zero. I am not familiar with this ABS.

Especially when I can press the Zero key setting at any position.

Maybe some of the readers have one already and can tell me

what ABS is use for? TIA