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Size: 2025
Comment:
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Size: 2114
Comment:
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| Deletions are marked like this. | Additions are marked like this. |
| Line 21: | Line 21: |
| * Inclinometer installed on the Mambo2 platform | * An inclinometer was installed on the Mambo2 platform (see picture below) to measrue the vibrations during the measurements. |
| Line 25: | Line 25: |
| * On-off measurements on an absorber. The on-off are done w/o the wobbler taking offset in azimuth and elevation to activate the Basic or Cascade controller. The Basic/Cascade limits are (600,400) arcsec in (Azimuth,Elevation). The Basic controller has a smoother behavior than the Cascade controller. | * On-off measurements on an absorber. The on-off are done w/o the wobbler taking offset in azimuth and elevation to activate the Basic or Cascade controller. The Basic/Cascade limits are (600,400) arcsec in (Azimuth,Elevation). |
| Line 27: | Line 27: |
| * An extra weight is added on the bolometer platform to check the effects of a change in the platform response to the vibration. | * An extra weight was added on the bolometer platform to check the effects of a change in the platform response to the vibration. |
| Line 30: | Line 30: |
| * Oscilloscope monitoring directly on Mambo2 are performed during an on-off measurements, | * Oscilloscope monitoring directly on Mambo2 was performed during an on-off measurements. * You can find the list of the absorber on-off scans [: AbsorberTests:here] |
Tests performed during the heavy maintenance (2007.06.20)
Goals
Identify the origin(s) of the "acceleration" problem in MAMBO2. We want to answer the following questions:
- Is the acceleration problem due to a mechanical or electrical process ?
- What is the influence of the driving program on its intensity (Basic/Cascade) ?
People
Pico Veleta: DJ, SL, SN, JP
Methods
- An inclinometer was installed on the Mambo2 platform (see picture below) to measrue the vibrations during the measurements.
attachment:inclinometerPhoto.jpg
- On-off measurements on an absorber. The on-off are done w/o the wobbler taking offset in azimuth and elevation to activate the Basic or Cascade controller. The Basic/Cascade limits are (600,400) arcsec in (Azimuth,Elevation).
- An extra weight was added on the bolometer platform to check the effects of a change in the platform response to the vibration.
- Oscilloscope monitoring directly on Mambo2 was performed during an on-off measurements.
You can find the list of the absorber on-off scans [: AbsorberTests:here]
Results
- Inclinometer measurements for two on-off measurements with the Cascade and the Basic controller.
BR attachment:inclinometerBolo.jpg
- On-off measurements with the offsets in elevation: 360" (scan 47, Cascade) and 440" (scan 50, Basic)
BR Cascade controller attachment:scan47-elev-cascade.jpg
Basic controller attachment:scan50-elev-basic.jpg
- An extra weight was put on the bolometer platform (scan 51)
attachment:scan51.jpg
- Measurements of electrical peak with the oscilloscope during an on-off measurements with the offsets in elevation (scan 53).
No correlation was found between the beginning of the scans where the extra noise peaks appeared and the electric activity. A peak frequency of 5 sec was observed but which may be related to the air conditioned system.