1. Metrology Issues 9/11/07

2. Metrology Troubleshooting Advertised tolerance: +/-.0027” @40”; typical +/- 0017” @40’. Not sure what these mean. –We fall within +/-.0027” if we ignore outliers in data. –We see a scattering of data – numbers jump +/-.0027” –Our equipment may be working within advertised limits! Backed out of Windows updates- no effect. Tried various versions of VeraSerf- no effect. Changed computers – no effect. Added new wireless network adapters – no effect. May have a combination of problems. Leika checked in RadWaste bldg. This is a low noise environment. Not much difference.

3. Cloud drift over time (30’ away) Approx. 0.007” excursion Approx. 8 mils

4. Other Notes In build mode, the data would shift with time much more than previously. (screen data would change ) Is it real mech. noise? Room may be moving. –Pressure variation effects on wall & floor –Air currents When tested in Rad Waste to eliminate these, there was NO EFFECT. Non mech. noise –Grounding. With battery power, no effect. –EMI/RFI/wireless radio – changed network cards; checked with suppliers; don’t seem to be the problem. Mech. Noise – vibration, etc. –Looked at targets with optics – didn’t observe motion. –Temperature – varies in room 5-6 degrees at times in a shift. 2 effects: thermal growth of parts; parts shifting There is a compensation function in VeraSerf which we need to learn more about. –However, it’s not very sophisticated. Still need to resolve this one. Magnetic effects – Marked checked with manufacturer – they felt their equipment is not sensitive to the stray fields we have in the test cell; their holders have a stronger field. Bottom line: It’s not working far outside of its advertised values. We may have a number of small effects which are adding up to put us at the outer limits of the device accuracy.

5. Possible next steps Getting external experts (BNL? Fermilab?) Plan to go to Farro to check out our serviced laser tracker with our computer. PLAN: proceed with measurements, but with caution. –Develop standard procedures. Steve will call Joe Error at SNL and see if he’s willing to come to PPPL with his laser tracker and spend a few days here to check performance in our environment.