calum.torrie@LIGO.ORG - posted 08:28, Thursday 26 June 2014 - last comment - 12:28, Monday 30 June 2014(12488)
Particle Counts BSC3
Particle Counts were taken in BSC3 before and during work activity on the ITM quad. Counts were very high, see below. Work continued because the ITM will be cleaned again before close and because of pressing needs from other groups. Refer to LIGO-T1400024-v4 (https://dcc.ligo.org/LIGO-T1400024) for guidance on particle counts. Would like to see push and draw cross-flow system setup at BSC3. start of work (2 bodies in chamber, no work) 0.3 um 1020 1.0 um 160 5 minutes after above (same 2 bodies, no work) 0.3 um 964 1.0 um 174 5 minutes after above (same 2 bodies, no work) 0.3 um 560 1.0 um 80 5-10 minutes after above (same 2 bodies, no work) 0.3 um 380 1.0 um 50 5 minutes later (same 2 bodies, with some "walking" in chamber) 0.3 um 540 1.0 um 120 5 minutes later (prep for sleeve removal, now 3 bodies) 0.3 um 780 1.0 um 190 5 minutes later (after sleeve removed, now 3 bodies) 0.3 um 1270 1.0 um 210
On Thursday 26th June (following these counts being raised at the morning LHO meeting Bubba et al set up the draw fan on the BSC3 door (opening) as per the attached picture, DSCN0367.jpg. Following the installation of the draw fan I went back to take readings in and around WBSC3. The readings were as follows: - 1) In clean-room outside WBSC3/1 (in middle of room). 0.3 um 50 1.0 um 20 2) In clean-room outside WBSC3/1 (adjacent to draw fan). 0.3 um 10 1.0 um 0 3) In clean-room (in front of draw fan). 0.3 um 150 1.0 um 30 4) In WBSC3 (at opening). 0.3 um 80 1.0 um 10 5) In WBSC3 (just inside chamber). 0.3 um 170 1.0 um 40 6) In WBSC3 (above open flooring, below ITM). 0.3 um 260 1.0 um 70 Clearly the installation of the draw fan has made a marked improvement. However, more measurements are required to confirm this in the longer term. Refer to alog entry https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=12529 for follow up reading taken on the 30th June 2014. ACTION - At next opportunity i.e. when optic can be protected by lens cap the floor (of the chamber) and the flooring should be wiped and vacuumed. Jeff Bartlett has this on his to do list.