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
Emile de Rijk, EE mechanics meeting, 26/08/2004, 2
Tolerances and measuring points
In total we measured 73 alveolas
tolerances Y
X
Emile de Rijk, EE mechanics meeting, 26/08/2004, 3
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
Emile de Rijk, EE mechanics meeting, 26/08/2004, 4
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
Emile de Rijk, EE mechanics meeting, 26/08/2004, 5
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
Emile de Rijk, EE mechanics meeting, 26/08/2004, 6
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
Y3Average:154,226 mm Sigma: 0,085 mmY4Average:154,248 mm Sigma: 0,063 mm
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
X3Average:154,549 mm Sigma: 0,144 mmX4Average:154,357 mm Sigma: 0,120 mm
Emile de Rijk, EE mechanics meeting, 26/08/2004, 7
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
Y1Average:154,25 mm Sigma: 0,065 mmY2Average:154,28 mm Sigma: 0,063 mm
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
Emile de Rijk, EE mechanics meeting, 26/08/2004, 8
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
Y3Average:0,026 mm Sigma: 0,048 mmY4Average:0,029 mm Sigma: 0,059 mm
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
Emile de Rijk, EE mechanics meeting, 26/08/2004, 9
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
Y3Average:0,009 mm Sigma: 0,037 mmY4Average:0,004 mm Sigma: 0,037 mm
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
X3Average:0,016 mm Sigma: 0,038 mmX4Average:0,002 mm Sigma: 0,053 mm
Emile de Rijk, EE mechanics meeting, 26/08/2004, 10
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
Emile de Rijk, EE mechanics meeting, 26/08/2004, 11
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