I moved the Guralp box's input terminator from Gur1 to Gur2 a minute or so ago to check the other channels.
Now that the MC is back up and running, I put the Guralp seismometers at the ends of the mode cleaner. Gur1 is near MC2, and Gur2 is near MC1 (yes, it seems backwards....that's how the cable lengths work). Also, the set of 3 MC2 accelerometers are in place under MC2. I can't find the black cube for the other set of accelerometers, so there aren't any around MC1/3.
In order to identify the output adapter of the BNC patch panel used for about 20 PEM channels, I had to disconnect its power and remove the back panel. Channels coming into that panel (seismometers and so forth) was out from 1:36 to 1:56 pm.
I did a quick check of some of the channels and it looks like its working again after putting it all back together.
Kevin sent me an email with top secret info on where one of the other accelerometer cubes was hiding (it was with his shaker setup on the south side of the SP table), so I took it and put the 3 MC1 accelerometers in their 3-axis configuration.
Also, I changed the orientation of both sets of 3 axis accelerometers to reflect a Right Handed configuration, to go along with the new and improved IFO configuration. Previously (including last night), the MC2 accelerometers were together in a Left Handed configuration.
The AC filters will be checked and/or replaced today. This means the AC will be off for sort periods of time. Temperature and particle count will be effected some what.
See 800 days plot
Sanjit discovered that the Gur1 channels are all digital 0. We determined that this began on July8, 04:00 UTC (~9pm on the 7th?).
It's digital zero, so we suspect a software thing. Just to check, we put a sine wave in, and didn't see anything. Gur2 seems totally fine, and the sine wave input showed up nicely on dataviewer. What's going on? Sabotage to prevent this paper from getting done? Dmass trying to get his paper done before me???
Investigations are ongoing.... Joe claims it's not his fault, since his shenanigans near the PEM rack were on days before, and days after this, but not on the 7th.
I just rebooted c0dcu1, which didn't help anything. Joe said he'd try to give me a hand tomorrow.
One of the Guralps [Gur2] has been taken to the atf gyro lab, along with the breakout box.
Edit by Jenne: This means that we have no working seismometers in the 40m lab right now, so don't worry if you're looking for seismo data and you can't find any. The 6 accelerometers should all still be up and running.
The control room temp is warmer than usual. The heat exchanger Office Pro 18 set point was lowered from 70 to 68F yesterday.
The MOPA headtemp is higher also. The Neslab chiller bath temp peaks around 21.6 C daily. This should be rock solid 20.00 C
It did not have any effect.
Now, I have just lowered the thermostat setting of room 101 from 73 to71F I hope Koji can take this.
Little change in the AC set temp can make wonders. Neslab chiller bath temp 19.99C is back to normal and daily variation of PSL are much better.
The lab is at 30,000 and Pasadena air is at 1.1 e+6 particles /cf min of 0.5 micron.
I brought the GUR2 seismometer back from Bridge so I can get some more MC/Seismic data during the next week while we're pumped down, before we start doing things to the PSL table. Both of the Gur Seismometers are connected back up to the breakout box as of ~3:27pm today. Alastair still has the handheld controller thing (which I use for mass centering, on occasion), since he'll want the seismometer back in a week or two when I'm done with it.
Something is wrong with both X channels of the Guralps. Alastair claimed that he and Frank didn't do anything bad when they opened up the breakout box, but I am suspicious.
While I'm at it, a reminder that Jan and his SURF student Greg still have the Ranger, disassembled over in Bridge. They made a note in their elog, but not in the 40m elog when they took it back again.
Whenever you're done with the Mode Cleaner for the next week, please make sure it is locked, nicely aligned and happy before you leave. Also please make a note of what you're doing and when, so that I know what is good data and what is data with unusual conditions.
In other, semi-bad news (but already recovered from), when I was finishing putting the Guralp Breakout Box back in the rack, I bumped the power strip that is on the top back side of the rack, near the corner that the door opens on (not the corner the door hinges on). I turned the power strip back on, and I think everything that is connected to it came back okay. Anyhow, my bad. Sorry.
Today's seismometer diagnosis activities are still underway, this is just an update (since I did some reboots):
Problem 1: X and Z channels on both seismometers were flipped. I unplugged an X cable (East/West on the cable labels) and the Z channel (vert) would go to floating ADC zero. Rana suggested that the ADCs sometimes have random channel hopping, and that a reboot of the c0dcu1 computer which handles the PEM ADCU should fix this problem. I keyed the c0dcu1 / c0daqawg crate, those computers came back just fine, and the channels were no longer flipped. This is a good thing. Although now it's actually the Z channels that were / are bad on both seismometers, not the X's.
While rebooting those computers, c1iovme, c1sosvme, c1susvme1 and c1susvme2 crashed. I rebooted them, although for the first few power cycles c1susvme1&2 couldn't mount /cvs/cds/caltech. Eventually they did, and life is good again. Except that the seismometers are still funny.
Some more progress, but still not complete:
Jan and I looked at all of the Gur channels on a 'scope (battery, so as not to be grounded), and 5 of the 6 looked good. We were looking at the BNCs just as they go into the ADC. The one which still looks bad is Gur1Z. The 'scope just doesn't see any signal on that channel.
In addition, the ADC's BNC input #4 (which normally has Gur2Z) looks totally shot. When it's floating, the signal on dataviewer definitely doesn't look floating. I'm probably going to have to move over to another channel, and just give that one up (this ADC already has several channels which have been declared bad, so maybe it's not a surprise that this can happen?)
Since one of the Gur signals looks bad (Gur1Z) and one of the ADC channels looks bad (usual Gur2Z), I switched the Z channels on the ADC board, so the channel being saved as Gur1Z is in fact Gur2Z. This is valid as of ~1:15am until further elog notice.
During my investigations into why Gur1Z is funny, I also looked at the signal on the BNC octopus cable coming straight from the output of the Guralp Breakout Box (this is the cable which goes from "ADC Out" on the back of the box which is a 37 pin D-sub to 9 differential BNCs), and sometimes I saw zero on the 'scope, but sometimes there was a signal which would coincide with jumping tests. Whenever there was a signal however, it was always a way lower amplitude (at least by a factor of 10?) than the other channels.
All of this craziness led to me pulling the Guralp box to investigate.
Upon opening the box, I recalled that the channels go in order: Vert, NS, EW. The Gur1Z channel is that first vert channel, and it's the one which always had a blue input capacitor rather than a surface mount one. Being suspicious of Frank and Alastair, since they seemed unhappy with my capacitor choices, I wondered if they had wiggled the blue cap, and tore something loose. Just in case, and to make things seem more uniform, I replaced the blue cap with a surface mount 1uF cap. (Actually its 0.909uF, replacing the 0.905uF blue cap, according to the black DMM that measures capacitance.) While I was in there, since it had been a problem in the past (elog 2811), I relflowed the solder on some of the resistors, especially near the output op amp.
Anyhow, none of that may have been necessary. All 6 of the Gur channels were examined on a 'scope, using clip doodles to measure the various Test Points on the circuit. I looked at all of the TPs in Gur1Z, and I didn't find that any particular stage was any noisier than the others. Also, all 6 of the Gur channels seemed totally fine in terms of sending a good signal to the output of the box, including Gur1Z which is currently under investigation. All of the channels passed the "output looks ~20x the input" test, and for approximately equal thumping on the ground all 6 channels seemed to have similar amplitude outputs. The Z channels on both channels one and channels two were a little bigger than the X's or Y's, but the 2 Z channels were about the same. This test was done using Guralp2 and the Gur2 cable on both channels 1 and 2, and then checked with Guralp 1, using the Gur2 cable on channels 1. The Vert1 channel always seemed good.
I now am suspicious of one or more of the cables: either the Gur1 cable from the seismometer to the box, or the Vert1 channel of the octopus cable. I'm satisfied that the BNC cables running through the cable tray are okay (although it might not hurt to check that they all successfully send a sine wave...) I opened up the backshell of the Gur1 cable, on the end that connects to the breakout box. Nothing seemed amiss. I still need to Beep the cable to check its connections, and look at the octopus cable.
Recap / Current Status: Breakout Box is reinstalled, both seismometers hooked up. The Z channels on the seismometers are swapped at the ADC input. The dataviewer channels Gur1_X, Gur1_Y, Gur1_Z (which is actually Z of Gur2 seismometer) and Gur2_X, Gur2_Y are all good. Nancy is going to leave the MC in a happy place, and note the time when she's done. Tomorrow I'll check out the cables for the Gur1Z seismometer channel.
After some cable swapping this morning, I have determined which cable is bad. It's the Gur1 cable between the seismometer and the breakout box. This is a milspec -> 37pin d-sub cable. I'll pull out the cable and have a look at it after lunch.
[Jenne and Koji]
In order to characterize the seismic vibration of the PSL table, we put the accelerometers on and below the PSL table.
On the PSL: MC2 Accelerometers (X, Y, Z) - being connected to CH1-3 of the preamps
East side of the PSL table. X, Y, and Z is directed to North, East, and Up.
On the ground: MC1 Accelerometers (X, Y, Z) - being connected to CH4-6 of the preamps
Beneath the West side of the PSL table. X, Y, and Z is co-aligned to the MC2 ACC.
I found that the C1:PEM-ACC_MC1_Z has large noise in the low freq (~1Hz) region. I tracked down the noise source
and found the noise is still present in the down stream even when the CH17 (C1:PEM-ACC_MC1_Z) of the ADC IF BNC
(@1Y7) was terminated.
I consulted with Jenne and decided to connect this channel to CH14, which is vacant and has name
(for the details of the channel configurations, see /cvs/cds/caltech/chans/daq/C1ADCU_PEM.ini)
I first tried magnetometer channels to steal, but they didn't seem reacting (and the connected to the wrong channels).
I am feeling that we should once entirely check the I/F box.
Note that there looks the difference of the gain by x10 between C1:PEM-ACC_MC* channels and C1:PEM-AUDIO_MIC2.
[From Jenne: The gain difference is because the C1:PEM-ACC_MC* channels have gain=10 in the .ini file, while C1:PEM-AUDIO_MIC2 uses the default gain=1. ]
So, I was wrong about which cable it was, probably in my rush to get some lunch. The actual culprit was the octopus cable that Bob made waaay back in the day (~2 years ago) to go from the "ADC out" of the breakout box (37pin Male Dsub) to 9 BNCs. As it turns out, the Gur1Z channel of that cable was broken on both ends!!!
On one end, we have the 37 pin Dsub. The cable used was so thick (way too thick for this application) that it made a super rigid connection between the wires and the connector, and any bending of the cable stressed this connection, despite the strain-relief of the backshell. The Gur1Z connection snapped off when I was gently wiggling the connections to check them out. Also, since the wires were all so thick, they didn't really fit into the hole in the backshell, so 2 or 3 of them were squished.....straight through the insulation so that several channels were shorted together / potentially shorted to ground. This may explain some of the nasty behavior that Rana and I had seen (although I might have forgotten to elog? My bad.) that even with the inputs of the breakout box all terminated, there was high coherence between the channels. Terminated inputs should give random noise, so this was fishy.
On the other end of the cable we have the 9 BNCs. I had finished redoing the 37pin end of the cable, and was 'beeping' it to check it out, when to my dismay I found that the Gur1Z channels (the inside and the outer shield of the BNC connector) were shorted together. I removed these 2 wires from the Dsub connector to confirm that the BNC was at fault. Koji looked at the BNC with me after I chopped it off of the cable. Bad news strikes again. To get the wires to fit in the inner pin of the BNC connector, the cable-maker had cut off several strands of the wire to make it skinnier. It appears that over the years these cut-off strands wiggled their way to touching the outer shield. This appears to be a danger for all of the BNCs on this cable: a little bit of torque (which one might expect during plugging and unplugging a BNC) and the 2 sides of the differential measurement will be shorted together.
I then decided to start afresh and make my own cable. I found some AWG26 8-twisted-pair cable laying around underneath the Yarm (since this was all I could find, I was just going to do the Gur1 and Gur2 channels, and leave out the Gur3's). The 37 Dsub side was easy, but I seem not able to connect such skinny wire to the BNC connectors in a robust way. Since this bad cable has so far cost me ~2.5 16-hour days of grief, I don't want my new version of it to also be bad. At this point, I await the advice of one wiser than I. I think BNC connectors are designed for something a little closer to ~20AWG, but I could be wrong. Also, they are obviously optimized for coax cable. So what I have now is never going to be great. Maybe tomorrow I can go to the Electronics Shop / Store and buy BNC connectors that are meant to be soldered-to. That would be awesome.
Since I currently have no functional cable to go from Breakout box to ADC, the Guralps are unplugged for tonight.
Conclusions for the day / evening: Frank, Alastair and Jenna are mostly absolved of blame, although the traveling to Bridge and opening and closing the box (which usually involves more plugging and unplugging of cables) probably didn't help this cable out too much. Also, Bob definitely owes me a Sugar Napoleon or something.
In other news, since the Gur2Z ADC channel is totally wacked, I have taken over (but not renamed) the Ranger channel for Gur2Z for now. Jan still has the Ranger hostage over in Bridge, so this is okay for now.
After much hassle, the Guralp cable from the ADC Out of the breakout box to the ADC is fixed, and everything is plugged in and working again. The seismometers are back in their regular positions at the ends of the MC, ready for some excellent seis/MC combo data.
I solidified the change of putting the Gur2Z channel into a different BNC input on the ADC. The C1ADCU_PEM.ini file has been changed so that what used to be the Ranger's channel is now recognized as Gur2Z.
Also, I changed the same .ini file to reflect Koji's move of ACC_MC1_Z to the old AUDIO_MIC2 channel, so now all 6 Accelerometer channels have the same calibrations again.
Another big change is the change from old-left-handed convention to new-right-handed convention. The seismometers are aligned the same way they always have been (with the North-South markers aligned with the MC), but now the North-South output is plugged into the BNC on the ADC that is associated with Gur*_X, and the East-West output is plugged into the ADC channel associated with Gur*_Y. This is true for both Guralp Seismometers.
So, now we have:
Gur1_X = Gur1_NS = ADC#10
Gur1_Y = Gur1_EW = ADC#11
Gur1_Z = Gur1_Vert = ADC#12
Gur2_X = Gur2_NS = ADC#2
Gur2_Y = Gur2_EW = ADC#3
Gur2_Z = Gur2_Vert = ADC#24
SEIS_Ranger_Y = no longer in the .ini file
We wanted to characterize the PSL table before the work before its lifting up.
We put a set of three-axis Wilcoxon accelerometers on the ground and another set on the PSL table through the weekend.
- The data at 9th Aug 00:00(UTC) is used. This was Sunday 5PM in the local time.
- The freq resolution was 0.01Hz. The # of avg was 50.
- The accelerometer signals were calibrated by the value 1.2e-7 V/(m/s^2). We use this absolute value of the spectrum for the comparison purpose.
- The accelerometers were aligned to North(X), East(Y), and Up(Z). There was the coherence observed from 2~20Hz.
The transfer functions are valid only this frequency region although we still can set the lower bound of them.
- The transfer functions in the horizontal directions show huge peaks at around 20Hz. The Q of the peaks are ~30 to ~100.
The vertical transfer function shows somewhat lower peak at around 50Hz with Q of ~10.
- The low resonant freq and the high Q of the horizontal mode comes from the heaviness of the table.
- We are going to raise the table. This will usually mean that we get the lower resonant freq. This is not nice.
- So, the decision to use 6 tripods rather than 4 was right.
- The steel tripods are expected to give both more rigidity and more damping than the chep-looking hollow Newport legs.
- Concrete grouting of the tripods will also lower the effective height and will benefit for us.
Koji, Rana and Steve
The floor preparation continued today. The really messy part of drilling and jack-hammering the concrete were done in controlled manner.
Particle counts peaked at 106K of 0.3 micron and 13 K of 1.0 micron particles/ cfmin at the top of SP table.
Legs were installed with the help of Koji and strongman Rana. Professor Rana was very useful lifting the 85 lbs legs.
Atm1, Drilling holes for ribbed bar reinforcement of concrete
Atm2, Koji and Rana are playing hide and seek while installing legs
Atm3-4, 6 Rigid tripod legs attached by 6x3 of 1/4-20x 7/8 screws. The top plates of the legs were torqued to 108 ft/lbs by Rana
Tuesday, 17 August : fill tunnel, set table height, level table and balance load
Wednesday : grout tripod legs and leave it alone
Thursday : built guide-form for concrete
Friday : pour concrete
Monday, 23 August : remove guide forms and clean up
Rana, Koji, Alberto and Steve, Tuesday afternoon
Atm3, Part of the tunnel under the table was filled with quick drying concrete this morning to give solid support for tripod legs.
PVC tube 6 " ID with TEE will able us to connect AP table, PSL table and Control room if needed
Atm4, Table height set to equal AP at ~32.75 " on copper plates using 5/8-11 x 4.5" set screw-bolt in tripod foot
Rough leveling was done by 4 individual levels at the four corners with 9" long Stanley cast aluminum levels.
Load balancing of the total weight ~ 3000 lbs over 6 legs x3 = ~170 lbs on each jack screw with Snap-On torque wrench at 140 lbs/ft
Atm1, Three crew members at work. Prof. Rana's calibrated right hand was used at jack screws where insufficient space was available for socket head wrench.
Atm2, Table is ready for no shrink grouting now.
The 10' x 6' optical table is seating on 6 tripods. Each tripod leg has 3 feet. They are supported by jack screws against copper plates on the concrete floor. These set screws allowed us to set the height, level and distribute the load of the table.
To lock this position of the table grouting is used around the jack screws and between the concrete floor and the tripod feet.
Once the grout set the load will be carried by the hole feet of 4" x 3.25" x3 = 39 sq inches per tripod leg
These ~4" thick grouted islands of 8-9" OD will be covered by 4" concrete. The area between the legs will be filled with 8" thick concrete.
Cement based grout, early height change 0 - 4%, hardened height change 0 - 0.3%
Atm2-3, pouring grout
Atm4, south west leg is done
Tomorrow: setting up ribbed bars, building frame to hold concrete and pour concrete
The preparation for pouring concrete is continuing. The grout forms were removed. Half inch ribbed steel bars were epoxied into our 4" thick floor.
The concrete holding sides- forms are cut to size. They will be installed on Monday morning and pouring concrete should follow.
We can be planning for cleaning up on Tuesday
Atm1, epoxy used bars
Atm2, south west tripod feet grouted
Atm3, ribbed bars are getting ready
C1: PEM-count channels are dead since August 12, 2010
Bertine Robby, Bertin and Jerry completed the installation by pouring concrete yesterday and cleaning up today.
Atm1-2, steel bars, grouted feet and side forms are ready
Atm3, bounding agent is applied for better bounding
Atm4, pumping concrete
Atm5, shaker is used to fill-all
Atm6, late after noon the forms- sides were removed, NOTE: actual table to concrete distance is 12.75"
Atm7, construction people left and the tile man is on the way
The tile patching should complete today so tomorrow we can remove plastic covers.
The tile work was done yesterday after noon.
This morning Mike Gerfen and me lowered the enclosure frame to normal height.
Keven- janitor and I removed plastic covers from chambers, racks, SP, MC2 and clean tool boxes.
The afternoon Jenne, Kiwamu, Joe and Aiden cleaned the enclosure inside out. The particle count measured zero inside the enclosure with HEPAs on when the covers were
removed. The MOPA and all other components were happy to see us in excellent condition.
This table height is very user friendly!
Safety grounds were reconnected.
Atm1, new tiles around the concrete slab
Atm2, frame lowered with low cross bars reinstalled
Atm3, the enclosure frame's north west foot is connected to ground
Atm4, PSL optical table is connected to ground at the north east corner through 1 Mohm
Atm5, PSL optical table level at a stimulating, back-friendly height
I posted the crane safety document on the 40m wiki, vacuum page as 26 August 2010
Please add your comments and corrections.
The South End Crane will be balanced on Tuesday, 31 August 2010
This will mean that the back door of the south arm will be open on and off. Air quality will bad.
Please plan accordingly.
The PSL -leg concrete was sealed with a single coat of SCOFIELD Cureseal-S to minimize shedding of particles.
The optical table was covered and optics were removed from the shelf. Accelerometers were turned off.
I lowered room 101 thermostat setting from 74F to 72F
Our toilets were replaced by a green Gerber 1.6 gpf ( 6 lpf ) last week.
And I raised it back to 73F. The thermometers on the wall show 74-75F as the actual room temp. The dial on the temperature controller is not calibrated.
Crane balancing at the south end is continuing today.
The crane I -beam now leveled at all degrees of rotation. The lower hinge was moved southward about 1/4 of an inch. Performance was tested at 2000 lbs
Atm1, work in progress
Atm2, load test at 1 Ton
Atm3, service report
I played with the particle counter this morning. Now it's running and reading the correct numbers on the old COCHECKLIST.adl medm screen.
However, it can not be seen with dataviewer.
Koji just rebooted the frame builder and the problem was solved.
I turned off/on the power to the accelerometers in order to re rout their connections. I found cable connector body-nut #3 loose to Accelerometer 2X This connector should be checked for solid performance.
Cleaned up cables on the top and bottom. Vacuumed both areas. We still have some remaining shading from the MOPA umbilical and more unknown BNC cables hanging around.
Accelerometers xyz were moved from IOO-south/west corner to under PSL table. They were turned off for ~20 minutes.
Guralp was also moved eastward about 2 ft. It is not leveled.
This is part of the preparation to remove access connector.
Fire-smoke sensors in the vertex area #2-31, 2-30 east, 2-32 south/MC2 and 2-37 old control room area are turned off to accommodate the welding
activity of folding crane. These sensors will be reactivated at 3:30pm today.
Stay out of the 40m lab: IFO room till 6 pm today.
The new cord wheel was to big. They be back tomorrow?
The lab is open.
Please remember to cover the optical tables !
Joe showed me what was what with adding DAQ channels, and I have begun building a simulink model to acquire the PEM channels.
My models is in: /cvs/cds/rtcds/caltech/c1/core/advLigoRTS/src/epics/simLink/c1pem.mdl
Next on the to do list in this category: test which input connector goes with which channel (hopefully it's linear, exactly as one would think), and give the channels appropriate names.
I have made a little bit of progress on the PEM channels. I have begun writing up detailed instructions in the DAQ Wiki page on how to add a channel to the new DAQ system. I have followed those instructions thus far, and can see my channels in the .ini file (and in the daqconfig gui thing), but I don't have any channels in Dataviewer or DTT.
There are some tricky "gotchas" involved in creating new models and channels. Some examples include: No use of the characters "DUMMY" in any channel name. The makefile is specifically hardcoded to fail if that string of characters is used. Also, you must have at least 2 filter banks in every model. Why? No one knows. You just do. The model won't compile unless you have 2 or more filter banks.
My efforts today included ~3 reboots of the frame builder, and ~2 reboots of c1sus. When Kiwamu and I rebooted c1sus, we burt restored to some time in the last 24 hrs. Some of the SUS filters on some of the optics were not set correctly (things like the bounce roll filter), so we turned all of them on, and reset all of the input and output matricies to be the correct combination of +1 and -1's to make Pit, Pos and Yaw. The tuning seems to happen now-a-days in the gains for each DOF, and the gains were set correctly by the burt restore for every optic except PRM. We made some educated guesses for what the gains should be based on the other optics, and PRM is damping pretty well (these guesses included reducing the SIDE gain by ~10 from the BS SIDE value, since the analog gain of the PRM SIDE sensor is much higher than others). We'll have to fine tune these gains using some Yuta-developed method soon. Or find a burt snapshot that had some non-unity values in there.
The Seismometer channels are once more being recorded. Alastair brought Gur1 back from the ATF the other day, and today I put it in its place below MC2 (yeah, the numbers are backwards. But they always have been.)
I checked the matching between BNC inputs on the breakout box to the ADC channels as labeled in the SimuLink diagram. To do this I had all 32 channels activated, and I put a 1Hz, 1Vpp sine wave into various BNC inputs to see what channel they showed up as. At first things were a bit backwards (BNC channels 1-16 going to ADCs 16-31, and BNCs 17-32 going to ADCs 0-15), but then Joe quickly flipped the cables on the adapter board in the back and things are in the correct order now. Channel 1 on the BNC board corresponds to channel 0 on the ADC, etc.
I checked that jumping near each seismometer made the signals spike, which they did.
I then changed the channel names in the c1pem.mdl SimuLink diagram to match the old channel names for the Guralps and the accelerometers, and deleted all of the other channels that aren't being used. There's a table in the diagram to indicate what goes with what, as of today. If you do anything to the PEM diagram, please update the table so it's easy to look things up.
I recompiled the code, but have not yet restarted the frame builder since Zach and Kiwamu are working on some things in the chamber, and I don't want to be annoying (so the channels aren't actually being recorded quite yet).
Edit, 7:15pm: Just kidding. Something didn't work, and I have to track down what. I'm not getting any data yet.
The crane people are here. The Vertex chambers are covered with plastic. The PSL HEPAs will be running on high during the day.
It is going to be disturbingly noisy and dirty during the day. Please try start working in the evening if it can not wait till next week.
The air condition was off for the south arm. I turned it on.
Ansell AccuTech 91-300 clean room gloves ONLY in the 40m lab.
Cleaning and preparation must be carried out in these gloves also.
I unpacked the STS2 seismometers that we borrowed from LLO. They are sitting underneath the Xarm, in the middle of the mode cleaner, near the other seismometer stuff.