Can the T1 Tomahawk Digital Tape Measure perform incremental (relative) measurements?

Yes, the T1 can be "zeroed" from any position regardless of the amount of tape extended.  For example, if a user wanted to measure out a position every 14 5/8", rather than perform the match internally, the T1 can be reset every 14 5/8", with the click of a button, to reset counting at zero.