Emile de Rijk, EE mechanics meeting, 26/08/2004, 1 Alveola Measurements Report on the external...

Emile de Rijk, EE mechanics meeting, 26/08/2004, 1

Alveola MeasurementsReport on the external dimension measurements

Wolfgang Funk and Emile de Rijk

August 2004


Tolerances and measuring points

In total we measured 73 alveolas

tolerances Y

X


Use of the Mandrels– The mandrels were normally used to measure the external dimensions and to

obtain information about the dimension of the crystal holes. – After measurements on the touch-column with and without mandrels we only saw

less then 60 microns of difference after having measured 3 alveolas in both dimensions.

– We came to the conclusion that the mandrels were not required anymore for the external dimensions

– We did not measure the interior dimensions.

8-2-29 8-18 9-2-47

with mandrels

without mandrels

differencewith

mandrelswithout

mandrelsdifference

with mandrels

without mandrels

difference

y1 145,44 145,46 0,02 145,7 145,71 0,01 145,69 145,71 0,02

y2 145,47 145,44 -0,03 145,68 145,7 0,02 145,66 145,61 -0,05

y3 154,07 154,05 -0,02 154,28 154,29 0,01 154,26 154,25 -0,01

y4 154,06 154,08 0,02 154,3 154,3 0 154,3 154,32 0,02

x1 145,5 145,49 -0,01 145,94 145,95 0,01 145,69 145,66 -0,03

x2 145,66 145,64 -0,02 145,78 145,76 -0,02 145,91 145,86 -0,05

x3 154,34 154,29 -0,05 154,23 154,17 -0,06 154,37 154,37 0

x4 154,23 154,19 -0,04 154,44 154,45 0,01 154,26 154,27 0,01


The touch-column (absolute measuring device)– The alveola and the measuring device are placed on a marble table.– The measuring device is a column along which a pin can move vertically and

measure distances– The machine is calibrated so that the needle measures the distance between the

point measured and the table.– The standard deviation of the reproducibility was tested to be better than 20

microns


The relative measurements device

-The alveola is fixed on a bench with a pump

-4 sensors measure front and rear values separately at 1 cm of the edge of the alveola.

-The calibration is made with a reference module which has been measured with the touch-column.

-A zero is set for each sensor. The zero for each sensor is different for front and rear measurements.

-The relative values are added to the external dimensions of the reference module

-The results are directly saved in a file

-The reproducibility is better than 50 microns

-Mechanics : José Mulon -Software : Xavier Pons


Relative measurement device results (in absolute values)

Relative measurements values for Y1 and Y2

0

5

10

15

20

25

30

35

145,0000 145,5000 146,0000 146,5000

values (mm)

cou

nts Y1

Y2

series3series4

Y1Average:145,688 mm Sigma: 0,058 mmY2Average:145,674 mm Sigma: 0,063 mm

Relative measurements values for Y3 and Y4

0

5

10

15

20

25

30

35

153,5000 154,0000 154,5000 155,0000

values (mm)

cou

nts Y3

Y4Series3

Series4


Relative measurements values for X1 and X2

0

5

10

15

20

25

30

35

145,0000 145,5000 146,0000 146,5000

values (mm)

cou

nts X1

X2

Series3Series4

X1Average:145,702 mm Sigma: 0,149 mmX2Average:145,937 mm Sigma: 0,153 mm

Relative measurements values for X3 and X4

0

5

10

15

20

25

30

35

153,5000 154,0000 154,5000 155,0000

values (mm)

cou

nts X3

X4

Series3Series4



Touch column results

Y1 and Y2 absolute values

0

5

10

15

20

25

30

145,0000 145,5000 146,0000 146,5000

Values

co

un

ts

Y1

Y2

Series3

Series4

Y1Average:145.69 mm Sigma: 0,062 mmY2Average:145.66 mm Sigma: 0,067 mm

Y3 and Y4 absolute values

0

5

10

15

20

25

30

153,5000 154,0000 154,5000 155,0000

value

co

un

ts

Y3

Y4

Series3

Series4


X1 and X2 absolute values

0

2

4

6

8

10

12

14

16

18

20

145,0000 145,5000 146,0000 146,5000

value

co

un

ts

X1

X2

Series3

Series4

X1Average:145,74 mm Sigma: 0,144 mmX2Average:145.79 mm Sigma: 0,092 mm

X3 and X4 absolute values

0

5

10

15

20

25

153,5000 154,0000 154,5000 155,0000

value

co

un

ts

X3

X4

Series3

Series4

X3Average:154.30 mm Sigma: 0,107 mmX4Average:154.28 mm Sigma: 0,108 mm


Touch column - relative measurement device

Absolute - Relative values for Y1 and Y2

0,0000

10,0000

20,0000

30,0000

40,0000

50,0000

60,0000

-0,6000 -0,4000 -0,2000 0,0000 0,2000 0,4000 0,6000

difference (mm)

cou

nts Y1

Y2

Y1Average:0,000 mm Sigma: 0,029 mmY2Average:-0,019 mm Sigma: 0,034 mm

Absolute -Relative values for Y3 and Y4

0,0000

5,0000

10,0000

15,0000

20,0000

25,0000

30,0000

35,0000

40,0000

45,0000

50,0000

-0,6000 -0,4000 -0,2000 0,0000 0,2000 0,4000 0,6000

difference (mm)

cou

nts Y3

Y4


Absolute - Relative values for X1 and X2

0,0000

5,0000

10,0000

15,0000

20,0000

25,0000

30,0000

35,0000

40,0000

-0,6000 -0,4000 -0,2000 0,0000 0,2000 0,4000 0,6000

difference (mm)

cou

nts X1

X2

X1Average:0,043 mm Sigma: 0,060 mmX2Average:-0,149 mm Sigma: 0,142 mm

Absolute - Relative values for X3 and X4

0,0000

5,0000

10,0000

15,0000

20,0000

25,0000

30,0000

35,0000

40,0000

-0,6000 -0,4000 -0,2000 0,0000 0,2000 0,4000 0,6000

difference (mm)

cou

nts X3

X4

X3Average:-0,255 mm Sigma: 0,188 mmX4Average:-0,074 mm Sigma: 0,045 mm


Comparison between the Russian and the touch-column results

Russian - Absolute values for Y1 and Y2

0

5

10

15

20

25

30

35

40

-0,6 -0,4 -0,2 0 0,2 0,4 0,6

difference (mm)

counts Y1

Y2

Y1Average:-0,054 mm Sigma: 0,047 mmY2Average:-0,048 mm Sigma: 0,037 mm

Russian - absolute values for Y3 and Y4

0

5

10

15

20

25

30

35

40

-0,6 -0,4 -0,2 0 0,2 0,4 0,6

difference (mm)

cou

nts Y3

Y4


Russian - Absolute values for X1 and X2

0

5

10

15

20

25

30

-0,6 -0,4 -0,2 0 0,2 0,4 0,6

difference (mm)

cou

nts X1

X2

X1Average:-0,126 mm Sigma: 0,075 mmX2Average:0,003 mm Sigma: 1,062 mm

Russian - Absolute values for X3 and X4

0

5

10

15

20

25

30

35

40

45

-0,6 -0,4 -0,2 0 0,2 0,4 0,6

difference (mm)

cou

nts X3

X4



Accepted alveolas (using touch-column results)

• Considering our results we looked at the number of alveolas that were within the tolerances

• We first made a table of refused and accepted alveolas with the standard tolerances. As our reproducibility was of 50 microns we decided to make a new table with enlarged tolerances of 50 microns for lower and upper limit.

With initial tolerances

Accepted Refused

X1 55% 45%

X2 44% 56%

X3 77% 23%

X4 78% 22%

Y1 96% 4%

Y2 96% 4%

Y3 86% 14%

Y4 92% 8%

Combined results: 100% alveola refused

With corrected tolerances

Accepted Refused

X1 63% 37%

X2 59% 41%

X3 92% 8%

X4 86% 14%

Y1 99% 1%

Y2 97% 3%

Y3 96% 4%

Y4 97% 3%

Combined results: 87% alveola refused


Conclusions:

– The mandrels are not needed for external dimension measurements at the edges of the alveola

– The touch column and the Russian measurements are correlated although there is a 125 micron systematic shift observed in X1 and X2

– The relative measurement device gives results that are often uncorrelated with the absolute measurement results, especially in X1 and X2

– The fact that the results of the relative measurement device deviate is partly due to the fact that the faces of the alveola are not flat.

– If we assume that our measurements are correct, we notice that the alveolas have some problems especially in the X1 and X2 dimensions.

– As in the X1 and X2 dimensions a good percentage of the alveolas are too big, all alveolas will probably have to be measured at CERN.

– Should we refuse some of the alveolas?– The polished alveolas will have to be inspected to see if they don’t suffer

from structural problems.

Note: a full report is being written and will be made available

Emile de Rijk, EE mechanics meeting, 26/08/2004, 1 Alveola Measurements Report on the external...

Documents

Transcript of Emile de Rijk, EE mechanics meeting, 26/08/2004, 1 Alveola Measurements Report on the external...