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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

Horizontal 20130224_1549_lws.dat
Vertical vertical not aligned properly

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

Axis Filename Gradient
Horizontal 20130224_1651_lws.dat -0.997163 +- 0.000019
Vertical 20130224_1642_lws.dat -0.999152 +- 0.000016

Vertical Horizontal
20130224_1642_lws_xy_fit_plot1.png 20130224_1651_lws_xy_fit_plot.png

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.

Topic attachments
I Attachment History Action Size Date Who Comment
PNGpng 20130224_1642_lws_xy_fit_plot1.png r1 manage 49.6 K 24 Feb 2013 - 08:02 LaurieNevay Vertical
PNGpng 20130224_1651_lws_xy_fit_plot.png r1 manage 50.9 K 24 Feb 2013 - 08:08 LaurieNevay Horizontal
PNGpng readout_problems.png r1 manage 31.7 K 24 Feb 2013 - 08:08 LaurieNevay Readout Problems

Physics WebpagesRHUL WebpagesCampus Connect • Royal Holloway, University of London, Egham, Surrey TW20 0EX; Tel/Fax +44 (0)1784 434455/437520

Topic revision: r1 - 24 Feb 2013 - LaurieNevay

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