Thanks for the recommendation of the PLS5 laser level. It is not cheap but it is a quality tool. And it is made in America.
http://www.plslaser.com/First of all, the PLS5 seems to be well within the stated tolerance of 1/8 inch on 100 feet. The manual or the PLS website suggest two ways of checking accuracy.
Second, the unit is shipped with a target–pendulum device. I could not really see or understand much about it by the pictures on their website. But it is a very handy well thought out device. Even after using it for several days I went back and read the instructions and learned more about how the pendulum could be used. Basically it is target that will swing and point down to plumb. Plus it has pins on the backside to transfer the point there if necessary. And the small horizontal tab on the pendulum lets you slide it up a wall and the laser will transfer the plumb point from the floor up to wherever on a wall. It is easier to see and understand in person than for me to explain it. I now see a video on the web site that will show it.
Thirdly, in addition to a stand for setting the unit on the floor, it has a convenient magnetic mount. I had it on one column and easily pivoted it around and marked the same elevation on all the other columns.
Thumbs up from me.