Measurement report of Boostec girders Control after receipt. Measurements performed on the 1 st and 2 nd of December 2010 with the Laser Tracker LTD500. Plan. INTRODUCTION Tolerances to be checked Coordinates system Flatness and coaxiality 3079 girder 3069 girder Positioning
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Measurements performed on the 1st and 2nd of December 2010 with the Laser Tracker LTD500
The objective of the measurements is to perform the dimensional control of the 2 Boostec girders after receipt at CERN (building 162). We measured these girders according to Nicolas Chritin plans and tolerances (EDMS n° 1098660) using the Laser Tracker Leica LTD500.
Measurement conditions were correct: temperature stability of 17.3°C to 17.8°C the 1st of December and of 17.1°C to 17.5°C the 2nd of December but lack of space.
We will present measurement results with an accuracy of about 10 µm rms for the flatness and coaxiality and of about 20 µm rms for the positioning.
We have not fully measured again Boostec girders but only checked the important points. The objectives were to check that girders were not damaged during transport and the machining of the side plans was consistent with the measurement report provided by Boostec (EDMS No. 1107158).
General tolerances of ± 0.01 mm, *Tolerances of ± 0.1 mm
The coordinates system is the same that the one defined on site (EDMS n°1103378):
_ Y axis = mean cylinders axis corrected by the offset generate by the cylinder diameter
_ Z axis = perpendicular to the mean plane A
_ System origin O = intersection of Y with the mean plane C
For the two Boostec girders, and with the consent of Nick Gazis, the planes D, H and I were not measured again.
_ Positioning of Bg with respect to the median plane: -64.904 mm instead of -65 mm
Positioning of Bd with respect to the median plane:64.974 mm pour 65 mm
Positioning of Fg with respect to the median plane: -64.976 instead of -65 mm
Positioning of Fd with respect to the median plane: 64.947 mm instead of 65 mm
The Bd and Fd planes have been enough machined to allow the use of shims.
_ Positioning of Bg with respect to the median plane: -65.057 mm instead of -65 mm
Positioning of Bd with respect to the median plane: 64.867 mm instead of 65 mm
Positioning of Fg with respect to the median plane: -64.971 mm instead of -65 mm
Positioning of Fd with respect to the median plane: 64.857 mm instead of 65 mm
The Bg plane seems not to have been machined enough of the order of 60µm, the CMM measurements by Boostec confirm that (EDMSn°1107158).