Starting Aug29, took elevation readings of the short HEPI Piers at HAMs 2 & 3; just the far outer corner of the pier as best I could put a ruler rod.  Also shot a few spots on the slab at the PSL Enclosure.

* The difference in the HAM2 and HAM3 average elevations is within 0.2mm of the design heights based on the LIGO Global Frame wrt local gravity.  The grout plates on which these piers reside would have been positioned in 1998 or '99!

* The HAM3 elevations have a runout of just 0.15mm; that is, deviation from the average.

* The HAM2 runout is 0.9mm.

* These runouts are seen as a potato chip or pringle as opposed to a simple tilt; see page 2 of attached notes.

* The PSL readings are a starting baseline, there is nothing previous to compare.

After we vent the vertex, I'll repeat these measurements to look for floor tilt in response.

Attached are my surveying notes.