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ID Date Author Type Categoryup Subject
  10948   Wed Jan 28 08:53:01 2015 SteveUpdatePEMSeismometer Vertex is covered

 

Quote:

I have just put the seismometers back into their nominal positions, on the concreted slabs.  The T-240 is in the vertex, and the 2 Guralps are at the end stations.

The vertex location doesn't have a spaghetti pot right now.  There is an aluminum support for cable trays that is welded to the supports under the beam tube that is in the way.  The pot looks like it will fit barely, if it were slid totally horizontally into place.  However we can't do that with the seismometer in place.  I'll chat with Steve this afternoon about our options. 

Since I don't know that we are planning on ever putting a cable tray on the inside of the beamtube, perhaps we can cut ~6 inches of this piece away. 

Aluminum support beam removed and seismometer is covered.

  10976   Wed Feb 4 19:21:45 2015 JenneUpdatePEMSeismometer Vertex is covered

I opened up the spaghetti pot over the vertex seismometer, and taped the cable to the slab.  The way the cable is coiled, it was touching the underside of the seismometer.  Now the only connection is at the cable connector.  There is a ~few inch bit of cable, then it's taped down. 

  10983   Fri Feb 6 10:03:23 2015 SteveUpdatePEMdusty days

 

Quote:

Yesterday morning was dusty. I wonder why?

The PRM sus damping was restored this morning.

Yesterday afternoon at 4 the dust count peaked 70,000 counts

Manasa's alergy was bad at the X-end yesterday. What is going on?

There was no wind and CES neighbors did not do anything.

Attachment 1: duststorm.png
duststorm.png
  11089   Tue Mar 3 02:43:06 2015 JenneOmnistructurePEMNo heat??

It's super cold in the control room and EE bench area tonight.  I'm wondering if, similar to what happened on Dec 29th (http://nodus.ligo.caltech.edu:8080/40m/10846) the campus steam is off?  Or just our heater is broken?  The thermostat is cranked up to 80 over by the bathrooms (this is usually ~74F), but we're still cold.

It's 69F in the control room right now (usually mid-high 70s).

EDIT, JCD, 4am: It's 64.3F in the desk area, 67.8F in the control room.  It also smells in the control room like some heater has been off for a while, and is turning back on - that burned dust smell that happens after you haven't turned on the heater all summer. 

EDIT again: The burn-y smell is getting stronger I think.  Security is sending someone over to come check it out.

  11091   Tue Mar 3 04:43:12 2015 JenneOmnistructurePEMOttavia is dead?

After some searching, including help from 4 security guys (I think they don't have a lot to do at 4:30am :), we found that Ottavia is super warm, and smelled burn-y.  She has been powered down and unplugged.  Security guys may call Steve's desk to follow up later today.sad

  11188   Wed Apr 1 10:50:59 2015 SteveUpdatePEMconstruction ahead

The 40m fenced area will start storing this large ~ 8000 lbs chamber on April 14. The asphalt will be cut, jack hammered the next 2-3 days in order to lay concrete.

Their schedule is from 8 to 5 starting tomorrow.  We are asking them to work from 6 to 3pm

ETMX is about 12-15 ft away

Attachment 1: largeMITchamber.jpg
largeMITchamber.jpg
  11203   Mon Apr 6 09:13:49 2015 SteveUpdatePEMjackhammering at ETMX
Quote:

The 40m fenced area will start storing this large chamber on April 14. The asphalt will be cut, jack hammered the next 2-3 days in order to lay concrete.

Their schedule is from 8 to 5 starting tomorrow.  We are asking them to work from 6 to 3pm

ETMX is about 12-15 ft away

Jackhammering was happening around 7:30am

It looks like it did no harm. It is too early to say what may have moved. Rana's worrisome  email was late.

The ground preparation is completed.

Attachment 1: jackhammerCalb.png
jackhammerCalb.png
Attachment 2: jackHcalETMX.jpg
jackHcalETMX.jpg
Attachment 3: jackHetmx.png
jackHetmx.png
  11204   Mon Apr 6 13:23:40 2015 ranaUpdatePEMjackhammering at ETMX

Unfortunately, this kind of trend plot is not detailed enough to know if something has gone bad in a quantitative way. But at least we can tell that the suspension wire didn't break.

  11205   Tue Apr 7 04:17:42 2015 JenneUpdatePEMjackhammering at ETMX

Q is writing the locking elog for the night, but just to reply to this thread:  The IFO worked well tonight, so things are at least not broken.

Quote:

Unfortunately, this kind of trend plot is not detailed enough to know if something has gone bad in a quantitative way. But at least we can tell that the suspension wire didn't break.

 

  11211   Thu Apr 9 07:41:22 2015 SteveUpdatePEMjackhammering at ETMX

There was a period of short unexpected jackhammering this morning. I asked them to stop.

The good mood of GTRX was not changed.smiley

 

Attachment 1: moreJackHam.png
moreJackHam.png
Attachment 2: GTRX.jpg
GTRX.jpg
  11217   Tue Apr 14 11:19:52 2015 SteveUpdatePEMlarge chamber has arrived

It is here.

Quote:

The 40m fenced area will start storing this large ~ 8000 lbs chamber on April 14. The asphalt will be cut, jack hammered the next 2-3 days in order to lay concrete.

Their schedule is from 8 to 5 starting tomorrow.  We are asking them to work from 6 to 3pm

ETMX is about 12-15 ft away

 

Attachment 1: ETMXfriend.png
ETMXfriend.png
Attachment 2: 8000lbs.png
8000lbs.png
  11259   Mon Apr 27 09:09:15 2015 SteveUpdatePEMair cond filters checked

 

Quote:

 

Quote:

Yesterday morning was dusty. I wonder why?

The PRM sus damping was restored this morning.

Yesterday afternoon at 4 the dust count peaked 70,000 counts

Manasa's alergy was bad at the X-end yesterday. What is going on?

There was no wind and CES neighbors did not do anything.

Air cond filters checked by Chris. The 400 days plot show 3 bad peaks at 1-20, 2-5 & 2-19

Attachment 1: 400d.png
400d.png
  11268   Sun May 3 01:04:19 2015 ranaSummaryPEMSeismo signals are bad

https://ldas-jobs.ligo.caltech.edu/~max.isi/summary/day/20150502/pem/seismic/

Looks like some of our seismometers are oscillating, not mounted well, or something like that. No reason for them to be so different.

Which Guralp is where? And where are our accelerometers mounted?

  11289   Wed May 13 10:07:36 2015 ranaFrogsPEMGuralp breakout paddle

Reward being offered for the safe return of this thing:

  11290   Wed May 13 13:33:34 2015 SteveFrogsPEMGuralp breakout box recovered

COD_Sugar napolion is due to Steve:  Item delivered, model CMG-SCU-0013, sn G9536

Quote:

Reward being offered for the safe return of this thing:

 

  11291   Thu May 14 17:41:10 2015 ranaUpdatePEMweather station and Guralp maintenance

Today Steve and I tried to recenter the Guralps. The breakout box technique didn't work for us, so we just turned the leveling screws until we got the mass position outputs within +/-50 mV for all DoF as read out by the breakout box.

Some points:

  1. GUR1 is at the ETMY (E/W arm) and GUR2 is at the X-end (South arm)
  2. The SS containers are good and make a good seal.
  3. We had to replace the screws on the granite slab interface plate. The heads were too big to allow the connector to snap into place.
  4. The Guralps had been left way, way off level and the brass locking screws were all the way up. We locked them down after leveling today. Steve was blaming Cathy(?).
  5. The GUR1_Z channel now looks good - see the summary pages for the before and after behavior. My mistake; the low frequency is still as bad as before.
  6. GUR2 X/Y still look like there is no whitening or if the masses are stuck or the interface box is broken.
  7. When we first powered them up, a few of the channels of both seismometers showed 100-200 Hz oscillations. This has settled down after several minutes.

 

The attachment shows the 6 channels after our work. You can see that GUR2_X/Y still look deadish. I tried wiggling the cables at the interface box and powering on/off, but no luck. Next, we swap cables.

Tried to bring the weather station back to life, but no luck. The unit on the wall is alive and so is the EPICS IOC (c1pem1). But there is apparently no communication between them. telnet into c1pem and the error message repeating at the prompt is:

Weather Monitor Output: NO COMM

Might be related to the flaky connector situation that Liz and I found there a couple summers ago, but I tried jiggling and reseating that one with no luck. Looks like it stopped working around 8 PM on March 24, 2014. That's the same time as a ~30s power outage, so perhaps we just need some more power cycling? Tried hitting the reset button on the VME card for c1pem1, but didn't change anything.

Let's try power cycling that crate (which has c1pem1, c0daqawg, and some GPS receiver)...nope - no luck.

Also tried power cycling the weather box which is near the BS chamber on the wall. This didn't change the error message at the c1pem1 telnet prompt.

Attachment 1: GurPost_150514.png
GurPost_150514.png
Attachment 2: secretWeatherTrends.png
secretWeatherTrends.png
  11295   Sat May 16 21:40:29 2015 ranaUpdatePEMGuralp maintenance

Tried swapping cables at the Guralp interface box side. It seems that all of our seismic signal problems have to do with the GUR2 cable being flaky (not surprising since it looks like it was patched with Orange Electrical tape!! rather than proper mechanical strain relief).

After swapping the cables today, the GUR2 DAQ channels all look fine: i.e. GUR1 (the one at the Y end) is fine, as is its cable and the GUR2 analog channels inside the interface box.

OTOH, the GUR1 DAQ channels (which have GUR2 (EX) connected into it) are too small by a factor of ~1000. Seems like that end of the cable will need to be remade. Luckily Jenne is still around this week and can point us to the pinout / instructions. Looks like there could be some shorting inside the backshell, so I've left it disconnected rather than risk damaging the seismometer. We should get a GUR1 style backshell to remake this cable. It might also be possible that the end at the seismometer is bad - Steve was supposed to swap the screws on the granite-aluminum plate on Thursday; I'll double check.

Attachment 1: GurPost_150516.png
GurPost_150516.png
  11309   Tue May 19 11:50:52 2015 manasaUpdatePEMNo noticeable effect from M4.0 earthquake

There was an earthquake: M4.0 - 40km SSW of South Dos Palos, California 

No noticeable effects on the IFO. MC did not lose lock; however the arms did unlock.

  11316   Tue May 19 19:24:30 2015 ranaUpdatePEMSeismic BLRMS filters

I was wondering about the design of the BLRMS fitlers for the seismic channels since the STS ones seem to have so little gain compared to the Guralps.

Here are some plots of the Bode magnitude and impulse responses of the bandpass filters (before the low passing). There's a bunch of entries from Masha on this from her SURF summer. Can anyone comment on why they are all so different?

One of the old Masha entries speaks of designing the lowpass filter in an intelligent way: by adjusting the filter order until the power in the stopband is less than 1% of the power in the passband. Seems like we could do that for bandpass too. For now I have made the names reasonable and changed all of the BP filters to 4th order Butterworth.

Also, it turns out that the Vel2Vel (gain ~0.02) filters were mistakenly on in the STS BP filter banks. The GUR inputs have a gain to scale the counts to velocity, but the STS seem to already be in microns/sec (where is this gain?) so I turned off and deleted the Vel2Vel filters; in any case the gain should not be done seperately in each BP bank, but altogether before the BP filtering.

Attachment 1: BLRMS_BP.pdf
BLRMS_BP.pdf
Attachment 2: BLRMS_imp.pdf
BLRMS_imp.pdf
  11324   Tue May 26 11:05:10 2015 SteveUpdatePEMworked around ETMY seism.

The cable tray holder cross beam is removed and cut short for good access to seismometer.

Attachment 1: ETMYseismic.png
ETMYseismic.png
Attachment 2: cut.jpg
cut.jpg
  11329   Thu May 28 10:42:19 2015 SteveUpdatePEMbad Guralp X-cable
Quote:

Tried swapping cables at the Guralp interface box side. It seems that all of our seismic signal problems have to do with the GUR2 cable being flaky (not surprising since it looks like it was patched with Orange Electrical tape!! rather than proper mechanical strain relief).

After swapping the cables today, the GUR2 DAQ channels all look fine: i.e. GUR1 (the one at the Y end) is fine, as is its cable and the GUR2 analog channels inside the interface box.

OTOH, the GUR1 DAQ channels (which have GUR2 (EX) connected into it) are too small by a factor of ~1000. Seems like that end of the cable will need to be remade. Luckily Jenne is still around this week and can point us to the pinout / instructions. Looks like there could be some shorting inside the backshell, so I've left it disconnected rather than risk damaging the seismometer. We should get a GUR1 style backshell to remake this cable. It might also be possible that the end at the seismometer is bad - Steve was supposed to swap the screws on the granite-aluminum plate on Thursday; I'll double check.

The Guralps were swapped.

What I did:   turned DC power off at 1X1,  hand carried them,  centered  each leveling bubbles, gently locked the jack screws and turned power back on.

ETMY at the east end now has CMG-T40-0008, sn T4157 as channel C1:PEM-SEIS_STS_1_Y_OUT_DQ.........

ETMX at south end now has CMG-T40-0053, sn T4Q17 as channel C1:PEM-SEIS_STS_2_Y_OUT_DQ.........

Conclusion:  Guralps are fine.  X  cable is bad. It was bad 6 months ago when it was made.

We can still swap the 3ft short cables at the granite base if Rana has not done it.

 

Attachment 1: Gurs180dXbad.png
Gurs180dXbad.png
Attachment 2: swappedGurs.png
swappedGurs.png
  11330   Thu May 28 15:10:44 2015 ranaUpdatePEMSeismic Confusion

You are plotting the STS channels, not Guralp. These are for the Trillium 240 seismometer.

Also, you cannot tell if the seismometer is working by plotting the MEAN trend. That just gives the average and we need the fluctuations. Better off looking at the spectrum like I did last time.

And....its not good enough to just do the bubble. You have to do the mass centering procedure that you and I did last time with the breakout paddle.

  11331   Thu May 28 16:43:52 2015 SteveUpdatePEMGuralps swapped

Koji and Steve,

The result: bad Guralp x-arm cable.

I will swap the short cables tomorrow at the base.

 

Attachment 1: GursSwapped.png
GursSwapped.png
  11341   Mon Jun 1 15:22:19 2015 SteveUpdatePEMGuralps X- short cable is bad

 

Quote:

Koji and Steve,

The result: bad Guralp x-arm cable.

I will swap the short cables tomorrow at the base.

 

Short 46" long cables at the base plates were swapped. Their solderings looked horrible.

This cable actually worked at 5-5-2015

Bad cable at ETMY station now.  The new cable should be a little bit longer ~52"

Attachment 1: seismGur1-2.png
seismGur1-2.png
  11345   Wed Jun 3 17:04:08 2015 ericqUpdatePEMWilcoxon Accelerometer Huddle Test

I've set up the Wilcoxon accelerometers on the SP table for a huddle test, to estimate their noise levels. 

They're clamped down to the table along the same axis, and their housings are in good contact, in hopes to make them as correlated as possible. 

Steve helped me move the DAQ cables from under the BS/PRM oplev table, to dropping from the cable tray above the POX table, so I could get them plugged in at the SP table. This also helps reduce the rats nest by the access connector, and is a fine location for when the accelerometers are attached at MC1 & MC2. 

A quick glance at DTT shows coherence of >0.9 from about 2-100Hz for all six. A three-corner-hat deal will provide an easy estimate of the noise floor of each one. If we feel like being fancy / accounting for possible gain differences, we could try some MISO wiener action, but that is probably overkill. 

Attachment 1: AccHuddle.jpg
AccHuddle.jpg
  11350   Wed Jun 10 02:50:39 2015 ericqUpdatePEMWilcoxon Accelerometer Huddle Test

Here are some results for the 3-corner hat subtraction for the six accelerometers, from ~1 hour of data that didn't look to have any sharp features/glitches from human activity in the lab. 

I used the python uncertainties package to try and get an estimate of the uncertainty in the subtracted noise floor, by taking into account every possible possible combination of 3 sensors and the fluctuations in the spectrograms of the subtracted signals. I've attached the python code if anyone is interested in the implementation. 

I pulled out the accelerometer data sheets to read their slightly varying V/g calibration (which differs on the order of a few percent from unit to unit). This improved the subtraction factor from ~20 to over 100 at some frequencies. I've edited the filter modules such that the OUT_DQ channels are already calibrated into m/s^2.

Attachment 1: hats2Acc.png
hats2Acc.png
Attachment 2: 3hatcode.zip
  11359   Mon Jun 15 16:55:39 2015 ericqUpdatePEMAccelerometers installed

The accelerometers have been installed at MC1 and MC2. MC2 data is live, I haven't yet run the cables from the MC1 set to the preamp yet, though. 

Attachment 1: MC2.jpg
MC2.jpg
Attachment 2: MC1.jpg
MC1.jpg
Attachment 3: mc2accspectra.png
mc2accspectra.png
  11362   Wed Jun 17 15:31:50 2015 ericqUpdatePEMAccelerometers fully installed

MC1 accelerometer has been plugged in. The modecleaner locking has been intermittent today, but I looked at a 15 minute lock in DTT, looking at the STS1 seismometer and both accelerometer triplets. Plot and DTT xml attached.

For the sake of not cluttering up everything with legends, the coherence plots are organized by direction (x, y, z), and include the coherence of each of the three sensors (sts, acc1, acc2) with the IMC control signal and the IMC transmitted RIN. 

Some remarks:

  • The 1 Hz pendulum motion is about equal amounts of X and Y, which makes sense, as MC1 and 3 are at an angle
  • The ~3 Hz stack motion seems to be entirely in the X direction. Why?
  • The bounce/roll bands are strongly coherent with Z motion at MC2. 
  • The STS does not appear to have any low frequency advantage over the accelerometers, in terms of coherence, contrary to what I would expect even without a thermal enclosure. 
  • The control signal and RIN RMSs are clearly dominated by noise in the 1-3Hz band, where we have reasonable coherence. Good prospects for noise subtraction...

Attachment 1: IMCcoherence_Jun172015.xml.zip
Attachment 2: IMCcoherence.png
IMCcoherence.png
  11367   Sun Jun 21 13:21:03 2015 ranaUpdatePEMWilcoxon Accelerometer Huddle Test

To improve our sensor noise estimate, the ACC cables should be clamped using a rubber pad and a big dog clamp on the SP tabletop before exiting the table. Also the sensors themselves should be covered with a foam box or a double cardboard box. The high-frequency acoustic noise may limit the 10 Hz performance since piezos are not very linear.

Quote:

I've set up the Wilcoxen accelerometers on the SP table for a huddle test, to estimate their noise levels. 

They're clamped down to the table along the same axis, and their housings are in good contact, in hopes to make them as correlated as possible. 

Wilcoxon. Not Wilconox or Wilco or Wilcoxen. Have some pity on future keyword searchers.

  11372   Tue Jun 23 11:18:20 2015 SteveUpdatePEMcleaning around chambers

Keven is our regular janitor is out for a few weeks.

The sub is careful- gentel Mario. We wiped arouind the vertex cambers north side on the floor and east arm racks.

 

  11388   Wed Jul 1 11:45:48 2015 SteveUpdatePEMcleaning around ETMX chamber
Quote:

Keven is our regular janitor is out for a few weeks.

The sub is careful- gentel Mario. We wiped arouind the vertex cambers north side on the floor and east arm racks.

 

Mario wiped the floor around the ETMX chamber today.

  11391   Sun Jul 5 18:14:13 2015 IgnacioUpdatePEMWilcoxon Accelerometer Huddle Test

Updated: On Thursday/Friday (sorry for late elog) I was messing with Eric's Wilcoxon 731A accelerometer huddle test data that was taken without the box and cables being adjusted properly. Anyways, I performed the three cornered hat analysis as he had done but I also performed a six cornered hat method as well instead of permuting around in pairs of three accelerometers. The following plots of the ASD's show the results,

It is interesting to note the improvement at low frequencies when six accelerometers are used instead of six while at higher frequencies we can clearly see how the results are worst than the three hat results.

I decided to take a mean of all six accelerometers measured ground signal as well as that for their computed selfnoises, this is plotted below,

 

Notice the obvious improvement along the entire frequency band of the measurements when all accelerometers are used in the data analysis.

I also performed some Wiener filtering of this data. There was an obvious improvement in the results,

The mean of the signals is also plotted below, just as I did with the cornered hat methods,

 

I also compared the mean self noise of the accelerometers against the manufacturers calculated selfnoise that Rana put up on Github. Both methods are compared against what the manufacturer claims,

As expected the measured noise curves of the Wilcoxon is not as good as what the manufactures stated. This should improve once we redo the huddle test with a better experimental setup. We have some pretty interesting results with the six cornered hat method at around 5 Hz, it is surprisingly accurate given how rough the calculations seemed to be.

I have attached my code for reference: code_accel.zipselfnoise_allsix.png

SEE attachments for better plots of the six accelerometers...

Attachment 5: code_accel.zip
Attachment 6: selfnoise_allsix_miso.png
selfnoise_allsix_miso.png
Attachment 8: selfnoise_allsix.png
selfnoise_allsix.png
  11439   Thu Jul 23 15:41:41 2015 SteveUpdatePEMfitting ants with TERRO

Pasadena got 0.2" of  rain on Saturday. Temperatures were high with high humidity since than.The ants were back in the Control room east side benches.

We have started using TERRO Liquid Ant Baits in January 2015   This worked very well to this point.

Tree new packages were opened  yesterday and the ants are gone.

We can conclude that these baits must be replaced after 6 mounts.

The liquid baits contains BORAX  and it is safe.

 

  11446   Fri Jul 24 23:08:53 2015 IgnacioUpdatePEMMC1 accelerators moved for future huddle test

I have moved the MC1 accelerators and cable to the huddle test set up, in order to see how a six witness huddle test with the improved set up will do. 

Here is a picture of the accelerometer set up,

Our motivation for doing this is to see if more witness signals used in the Wiener filter really does indeed improve subtraction, as it was seen from previous huddle results, specially in the region above 10 Hz.

  11460   Wed Jul 29 17:51:56 2015 IgnacioUpdatePEMAccelerators moved back to MC1 and MC2

We are done taking accelerator huddle test data. So I moved back all six accelerometers and cables to MC1 and MC2. I also relabel each of the accelerometers properly since the labels on them were confusing.

QED

 

Attachment 1: FullSizeRender.jpg
FullSizeRender.jpg
Attachment 2: FullSizeRender_2.jpg
FullSizeRender_2.jpg
  11464   Thu Jul 30 10:38:18 2015 SteveUpdatePEMY sesimostation is back on

Koji soldered new 50" long cable for the Y station.

 

Attachment 1: Guralps_are_back_on.png
Guralps_are_back_on.png
Attachment 2: Ystation.jpg
Ystation.jpg
  11466   Thu Jul 30 13:34:52 2015 KojiUpdatePEMY sesimostation is back on

Please check the spectra. If something is wrong, please swap the cables between X and Y in order to see if the cable is still the issue. I believe the cable was nicely made as I carefully checked the connection twice or more during and after the soldering work.

  11469   Thu Jul 30 15:24:54 2015 SteveUpdatePEMY sesimostation is back on

Atm1,  New short-50" long cable was installed at ETMY end ( Y-station ) between Guralp-B ( MIT ) and granite base.

Interface box input 2 was left connected to cable 1 and input 1 to cable 2. This plot shows no change.

 

Atm2, Than I swapped the two long cables at the interface box

                                                                                                   Now the signal seems to be ok <2 Hz,

                                                                                                                                                       >2 Hz some problem exist.

      Channel Name Location Seismometer 40m long cable

Interfacebox input

 

 50" short cable

C1:PEM-RMS_GUR2X_.... ETMX Guralp -A  2   2                             Jenne's friend                
C1:PEM-RMS_GUR1X_.... ETMY  Guralp-B  1   1  Koji

I will look for more bad soldering tomorrow. How many cables did she make?

 

 

Attachment 1: NewShortCable-Y-B-Gur2.png
NewShortCable-Y-B-Gur2.png
Attachment 2: interfaceInputSwapped.png
interfaceInputSwapped.png
Attachment 3: sameasAtm2.png
sameasAtm2.png
  11473   Fri Jul 31 10:36:22 2015 SteveUpdatePEMX seismo station short cable removed

 

Quote:

Atm1,  New short-50" long cable was installed at ETMY end ( Y-station ) between Guralp-B ( MIT ) and granite base.

Interface box input 2 was left connected to cable 1 and input 1 to cable 2. This plot shows no change.

 

Atm2, Than I swapped the two long cables at the interface box

                                                                                                   Now the signal seems to be ok <2 Hz,

                                                                                                                                                       >2 Hz some problem exist.

      Channel Name Location Seismometer 40m long cable

Interfacebox input

 

 50" short cable

C1:PEM-RMS_GUR2X_.... ETMX Guralp -A  2   2                             Jenne's friend                
C1:PEM-RMS_GUR1X_.... ETMY  Guralp-B  1   1  Koji

I will look for more bad soldering tomorrow. How many cables did she make?

 

 

We have to redo this cable also

Attachment 1: IMG_0009.JPG
IMG_0009.JPG
  11475   Sat Aug 1 20:46:29 2015 KojiUpdatePEMX seismo station short cable removed

OMG

  11487   Mon Aug 10 15:25:05 2015 SteveUpdatePEMwasp nest

The wasp nest will be removed tomorrow from from the out side of the east arm window.

The resonant frequency of the newly arrived gravity bee detector is not known.
 

Attachment 1: waspN.jpg
waspN.jpg
  11493   Tue Aug 11 11:56:36 2015 Ignacio, JessicaUpdatePEMWasps obliterated maybe...

The wasp terminator came in today. He obliterated the known wasp nest.

We discovered a second wasp nest, right next to the previous one...

Jessica wasn't too happy the wasps weren't gone!

  11497   Wed Aug 12 11:44:13 2015 ericqUpdatePEMGur2 Channels still wonky

In previous elogs, we saw that the X and Y spectra out of GUR2 (X end Guralp seismometer) looked strange (i.e. inconsistent with the GUR1 spectra). 

This morning, Steve and I brought the handheld control unit to the Guralp to center the test mass, by adjusting the centering potentiometers inside the unit while monitoring the voltage readout corresponding to the DC mass position (manual has instructions). 

At first glance, this seemed like the likely culprit, as the offsets for the horizontal directions were much larger than the vertical one. We zeroed all three to within a mV or two. Unfortuntately, the spectra look the same as they did 10 hours ago. no

Since we already had the kit out, we checked the offsets for GUR1. Only the "East/West" had an offset over 50mV, so we zeroed that one, but left the others alone. 

Attachment 1: gur2_centered.png
gur2_centered.png
  11505   Fri Aug 14 09:07:45 2015 SteveUpdatePEMGur interface box is wonky

Atm1, Before cable swap

Atm2, The long cables were swapped at the input of the interface box.

We can conclude that the problem is in the interface box

I wonder if interface box input 3 is wired?

Attachment 1: Gur1&2.png
Gur1&2.png
Attachment 2: longCablesSwapped.png
longCablesSwapped.png
  11506   Fri Aug 14 12:10:08 2015 KojiUpdatePEMGur interface box is wonky

Let's dismantle the I/F unit from the rack and connect the cable with the lid open.
We need to trace the signal.
 

  11507   Fri Aug 14 17:20:01 2015 JenneUpdatePEMGur interface box is wonky

IIRC, the Guralp box's 3rd set of channels do not have all of the modifications that were made on channels 1 and 2.

  11512   Mon Aug 17 17:48:12 2015 KojiUpdatePEMWasps obliterated maybe...

We found the same wasp in the 40m. Megan found it walking behind Steve desk!

  11514   Tue Aug 18 11:16:17 2015 SteveUpdatePEMGur interface box is wonky

The Guralp ADC  interface box  D060506 is ready for inspection. It is in front of 1X1 with open top and running.cool

Obviously c7 as 1 miroF cap is missing.blush

Quote:

Let's dismantle the I/F unit from the rack and connect the cable with the lid open.
We need to trace the signal.

 

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  11517   Wed Aug 19 07:58:25 2015 SteveUpdatePEMGur interface box

Koji and Steve,

We took transferfunctions of each channel yesterday. They were identical ?. I will check the cables from ADC to DAQ next.

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  11520   Thu Aug 20 11:31:55 2015 KojiUpdatePEMGur interface box

As reported previously, the transfer functions of the channels look fine. (i.e. All channels almost identical.)
I checked the chain from the unit input to the DAQ BNC connectors. They were all OK.

Today I have been checking the signals on the unit with the long DB37 cables connected.
I could not see anything on the Gur2 channels on the board. I looked at the DB37 for Gur2 and felt something is wrong.

I opened the housing of the cable and realized that all the pins are not fully inserted.
The wires were crimped improperly and prevents them to be fully inserted.

=> We need to redo the crimping to insert them.
=> We need to check the other side too.

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