Diff for "testMambo-20070620"

Tests performed during the heavy maintenance (2007.06.20)

TableOfContents

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

• Inclinometer installed on the Mambo2 platform

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). The Basic controller has a smoother behavior than the Cascade controller.
• An extra weight is added on the bolometer platform to check the effects of

a change in the platform response to the vibration.

• Oscilloscope monitoring directly on Mambo2 are performed during an

on-off measurements,

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.

Conclusions