20130224 Chamber Scale Cross Check

A cross check of the encoders for the chamber has never been done. They are industry standard and were supplied calibrated, but best to be sure. Cross check using readily available optical interferometer heads.

• Labview vi for readout reads out garbage about 60% of time so need many samples as there will be heavy filtering.
• 40 samples, 20 steps, 200um range

• Require more samples!
• 60 samples, 20 steps, 200um range
• Realign vertical sensor
• Keyence sensors seem to read negative or positive whilst in working range.

Vertical	Horizontal

The readout from the cross check monitors was quite a problem and the 'duff' numbers weren't always outside the range of the data - and therefore easily filtered out as shown below. The positions outside the displayed range have been filtered out of the data, however, some repeated points remain interspersed with the data - these can be identified as the repeated same value. This affects the average obviously and therefore the fit.

To within the alignment uncertainty of these cross check monitors as well as the resolution of both system, both measurement systems would seem to agree with each other.