ID |
Date |
Author |
Type |
Category |
Subject |
3551
|
Thu Sep 9 11:31:54 2010 |
steve | Update | PEM | accelerometer cable connection |
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. |
3585
|
Fri Sep 17 17:35:35 2010 |
steve | Update | PEM | cleaned up at 1Y1 PSL rack |
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. |
3646
|
Tue Oct 5 09:26:04 2010 |
steve | Configuration | PEM | moved accelerometers |
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. |
3752
|
Thu Oct 21 12:15:02 2010 |
rana | Update | PEM | 6.9 Mag EQ in Gulf of California |
Magnitude |
6.9 |
Date-Time |
|
Location |
24.843°N, 109.171°W |
Depth |
10 km (6.2 miles) set by location program |
Region |
GULF OF CALIFORNIA |
Distances |
105 km (65 miles) S of Los Mochis, Sinaloa, Mexico
125 km (75 miles) SW of Guamuchil, Sinaloa, Mexico
140 km (85 miles) NE of La Paz, Baja California Sur, Mexico
1200 km (740 miles) WNW of MEXICO CITY, D.F., Mexico |
Location Uncertainty |
horizontal +/- 6.1 km (3.8 miles); depth fixed by location program |
Parameters |
NST=187, Nph=187, Dmin=843.1 km, Rmss=1.17 sec, Gp=133°,
M-type=teleseismic moment magnitude (Mw), Version=6 |
Source |
|
Event ID |
us2010crbl |
|
3808
|
Thu Oct 28 09:16:17 2010 |
steve | Update | PEM | welding in the vertex area |
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. |
3810
|
Thu Oct 28 13:01:34 2010 |
steve | Update | PEM | crane repair guys left for the day |
Quote: |
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. |
3894
|
Thu Nov 11 11:08:26 2010 |
steve | Bureaucracy | PEM | AP table found open |
Please remember to cover the optical tables ! |
3977
|
Tue Nov 23 14:52:28 2010 |
Jenne | Update | PEM | PEM Model Started |
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. |
3985
|
Wed Nov 24 18:11:26 2010 |
Jenne | Update | PEM | Some progress on getting PEM channels |
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. |
4061
|
Wed Dec 15 18:29:59 2010 |
Jenne | Update | PEM | Seismometer Channels Being Recorded Again |
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. |
4165
|
Tue Jan 18 10:25:23 2011 |
steve | Update | PEM | vertex crane work this week |
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. |
4269
|
Thu Feb 10 11:16:31 2011 |
steve | Update | PEM | south arm AC turned on |
The air condition was off for the south arm. I turned it on. |
4386
|
Tue Mar 8 15:23:16 2011 |
steve | Update | PEM | clean room gloves |
Ansell AccuTech 91-300 clean room gloves ONLY in the 40m lab.
Cleaning and preparation must be carried out in these gloves also. |
4484
|
Mon Apr 4 11:52:13 2011 |
Jenne | Update | PEM | STS2s unpacked |
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. |
4550
|
Thu Apr 21 08:26:42 2011 |
steve | Update | PEM | PSL enclosure work today |
The east side window guides will be replaced by one long U-channel. There will be drilling into 2x2 steel frame. It should be done by 2pm today
This should remove the jerking motion of windows hitting the individual guides. |
4553
|
Thu Apr 21 15:20:46 2011 |
steve | Update | PEM | PSL enclosure work today |
Quote: |
The east side window guides will be replaced by one long U-channel. There will be drilling into 2x2 steel frame. It should be done by 2pm today
This should remove the jerking motion of windows hitting the individual guides.
|
The installation went smoothly. There will be no more banging the doors into guides on the east side.
Atm2 showing the west side as is today |
Attachment 1: P1070558.JPG
|
|
Attachment 2: P1070560.JPG
|
|
4825
|
Wed Jun 15 16:37:56 2011 |
Jenne | Update | PEM | PEM AA Board has been diagnosed and fixed |
[Jenne, Steve]
After talking with Steve, I had a look at the PEM's AA board, to see what the problem was.
Steve said the symptom he had noticed was that the Kepco power supplies which supply the +\- 5 V to the AA board were railing at their current limits as soon as he plugged the board in. Also, he smelled smoke.
I started with the power supplies, and saw that the 2 individual supplies each had a dV=5V, and that the one labeled +5V had the red wire on the + output of the power supply, and the black wire on the - output. The supply labeled -5V had the orange wire on the -output of the power suppy, and the black wire on the + output. Normally, you would expect that the 2 black wires are also connected together, and perhaps also to ground. But at least together, so that they share a common voltage, and you get +\- 5V. However these 2 power supplies are not connected together at all.
This implies that the connection must be made on the AA boards, which I found to be true. It seems a little weird to me to have that common ground set at the board, and not at the power supplies, but whatever. That's how it is.
The problem I found is this: The keyed connectors were made backward, so that if you put them in "correctly" according to the key, you end up shorting the +5V to the -5V, and the 2 black wires are not connected together. You have to put the keyed connectors in *backwards* in order to get the correct wires to the correct pins on the board. See the attached pdf figure.
Since these are internal board connections, and they should not ever be changed now that Steve has put in the adapter thing for the SCSI cable, I'm just leaving them as-is. Steve is going to write in huge letters in sharpie on the board how they're meant to be connected, although since this problem wasn't caught for many many years, maybe it won't ever be an issue again. Also, we're going to move over to the new Cymac system soon-ish. However, whomever made the power cable connector from the box to the board for this AA board was lazy and dumb.
After putting the connectors on the way they needed to be, Steve and I powered up the board, hooked up the SCSI cable in the back, and put a constant voltage (~1.3VDC battery) across various different channels, and confirmed that we could see this voltage offset in Dataviewer. (Kiwamu is hoarding both of our SRS function generators, so we couldn't put in a low freq sine wave like I normally would). Everything looked okie dokie, so I'll check the regular PEM channels tomorrow.
Steve will re-install the board in the rack in the morning. |
Attachment 1: 1X7_AAboard_connector_fix.pdf
|
|
4826
|
Thu Jun 16 00:39:08 2011 |
Koji | Update | PEM | PEM AA Board has been diagnosed and fixed |
As seen in the photo, the board has a strange bulge on the board,
and the color of the internal line around the bulge got darkened.
I don't trust this board any more. We should switch to the alternative one.
Quote: |
Steve will re-install the board in the rack in the morning.
|
|
4937
|
Tue Jul 5 08:32:38 2011 |
steve | Update | PEM | bad air quality in the lab |
The fireworks of yesterday showing up in the lab. Pasadena out side air 6.6 million cfm for 0.3 micron particles and 1.5 million cfm for 0.5 micron size. |
Attachment 1: badaq.jpg
|
|
Attachment 2: july4pem.jpg
|
|
5018
|
Fri Jul 22 14:22:13 2011 |
Ishwita, Manuel | Update | PEM | STS-2 seismometer hardware testing |
We have two STS-2 seismometer boxes... the blue box & the purple box. Initially we used the blue box for the STS-2 seismometer (named Bacardi by Jenne).
- Oscilloscope powered on battery was used to test the blue box by observing the velocity output of the three axes (X, Y, Z). It was found out that the mean value of DC volt of...
X = +10 V
Y = +11 V
Z = -0.1 V
Thus, X and Y axes showed abnormally high DC volt. It was also found out that in AC coupling mode of the oscilloscope... changes were observed in the signal received from Z axis when some seismic wave was generated near the Bacardi by jumping near it. No such changes were observed from signals received from X & Y axes.
- We removed the blue box and used the purple box for the same Bacardi seismometer & used the oscilloscope powered on battery to test it. It was found out that the mean value of DC volt of...
X = +4.4 V
Y = +4.4 V
Z = +4.4 V
In Ac coupling mode of the oscilloscope... changes were observed in the signals from X, Y, Z axes when someone jumped near Bacardi.
- The above voltages from the two STS-2 seismometer boxes are unsuitable for the ADC box since it works with voltages ranging from +2 V to -2 V.... meaning it will consider any voltage signal above +2 V as +2 V and any signal below -2 V as -2 V. Hence we need to find out how to use these STS-2seismometer boxes with the ADC box.
- We also tried measuring the DC volt from the shield and the center of a BNC connector corresponding to Y axis of the purple box (lets call it 'BNC-test') by using BNC-to-banana adaptors and banana wires. Signal from shield of BNC-test was sent to oscilloscope's channel 1 (connected to center of its BNC connector) and signal from center of BNC-test was sent to oscilloscope's channel 2 (connected to center of its BNC connector). On the oscilloscope screen it was observed that both the signals gave the same mean voltage output (-2.2V).
|
5033
|
Mon Jul 25 18:51:38 2011 |
Manuel | Update | PEM | STS-2 seismometer hardware testing with Jan |
[Jan, Manuel, Jenne]
Jenne called Jan to check and figure out why the Streckeisen seismometer (SN #100151) doesn't work, hence we checked the output of the seismometer boxes as we did last friday. (This is the problem of seeing the X and Y channels saturated, when we look at them on a floating 'scope, as in the linked elog entry.)
Jan unplugged and plugged again the orange cable into the seismometer and nothing happened. Well, what Jan was listening for was "clicks" inside the seismometer indicating that it was receiving power. We heard these, and moved on to examining the breakout boxes. Also, we checked that we could hear the "clicks" (one per mass) when we pushed the mass-centering button on the little green companion box.
We weren't sure that the purple box was working properly, so since we had seen the blue box work last time, we changed the purple box with the blue box in rack 1X6.
The Z-channel of the purple box returns a correct signal, that means that all the masses in the seismometer work (because the Z-signal is a linear combination of the three masses U, V, W), the X and Y channel have a DC component of about 10 Volts, Jan said that the recentering of the seismometer masses could need all the night, so we keep the power of the box on. If tomorrow morning the X and Y signal won't both be zero mean, we will open and check the box.
The power of the box is still on so that the masses can recenter overnight.
Edits by JD |
5045
|
Wed Jul 27 12:31:47 2011 |
Manuel, Ishwita | Summary | PEM | Weekly summary |
We kept reading about digital filtering
We tested the seismometer last friday
Jan came and tested again the seismometer last monday
We wrote a simulation of the stacks transfer functions, and of the distance between the mirrors.
|
5059
|
Fri Jul 29 12:25:54 2011 |
Ishwita, Manuel | Update | PEM | STS-2 seismometer box |
The 'Bacardi' STS-2 seismometer was tested with the "purple" breakout box and it was found out that all the three axes gave a voltage of 11 V (as shown on the screen of the oscilloscope) before pressing the auto-zero button and after pressing it the voltage shown was 6 V. We tried again the blue box and it was working perfectly after pushing the auto zero button (the auto zero took a few seconds). The power of the purple box is still on, we will wait a few hours, to see if something changes. |
5063
|
Fri Jul 29 18:43:02 2011 |
Manuel, Ishwita | Update | PEM | plugging seismometers to ADC |
[Manuel, Ishwita, Jenne, Jamie]
We changed the C1PEM model and the names of the C1:PEM channels.
We reinstalled the blue breakout box, since the purple one still didn't work.
So, now the AA board channels are connected as follows...
C1 = C1:PEM-SEIS_GUR1_X
C2 = C1:PEM-SEIS_GUR1_Y
C3 = C1:PEM-SEIS_GUR1_Z
C4 = C1:PEM-SEIS_GUR2_X
C5 = C1:PEM-SEIS_GUR2_Y
C6 = C1:PEM-SEIS_GUR2_Z
C7 = C1:PEM-SEIS_STS_1_X
C8 = C1:PEM-SEIS_STS_1_Y
C9 = C1:PEM-SEIS_STS_1_Z
C11 = C1:PEM-SEIS_STS_2_X
C12 = C1:PEM-SEIS_STS_2_Y
C13 = C1:PEM-SEIS_STS_2_Z
C14 = C1:PEM-SEIS_STS_3_X
C15 = C1:PEM-SEIS_STS_3_Y
C16 = C1:PEM-SEIS_STS_3_Z
C17 = C1:PEM-ACC_MC1_X
C18 = C1:PEM-ACC_MC1_Y
C19 = C1:PEM-ACC_MC1_Z
C20 = C1:PEM-ACC_MC2_X
C21 = C1:PEM-ACC_MC2_Y
C22 = C1:PEM-ACC_MC2_Z
Although the channels for all 3 STS-2 seismometers are made but only one is installed. So only Channels C1 to C9 are now in operation...
We checked the data from the plugged channels with the Dataviewer. We could see the peak whenever someone jumped in the lab. Even Kiwamu jumped and saw his signal. |
5134
|
Sun Aug 7 14:11:53 2011 |
Jenne | Update | PEM | Particle counts through the roof |
[Jenne, Kiwamu]
While Kiwamu was finalizing the X green alignment, I started to prepare to remove the ETMY door, and begin checking out its OSEMs, etc, so we could start moving it to it's new place, and figure out why it's been wonky for a while. I ran the particle counter, and we have a factor of ~5 more particles than normal. Kiwamu and I agreed not to open ETMY. Since we had briefly opened the IOO and Output Optics chambers to check the X green's position on the PSL table, we immediately shut those doors. They were probably open for ~15 minutes or so. (Yes Steve, we should have checked before opening any doors, but at least we remembered to check at all, and the doors were only open for a few minutes rather than for a few hours.)
I attach a 24hrs trend of the particle counts, for reference. It looks like it's been a little high for a while, but today it's really dirty in the air. |
Attachment 1: ParticleCount_High_7Aug2011.png
|
|
5140
|
Mon Aug 8 14:21:03 2011 |
steve | Update | PEM | Particle counts controlled |
Quote: |
[Jenne, Kiwamu]
While Kiwamu was finalizing the X green alignment, I started to prepare to remove the ETMY door, and begin checking out its OSEMs, etc, so we could start moving it to it's new place, and figure out why it's been wonky for a while. I ran the particle counter, and we have a factor of ~5 more particles than normal. Kiwamu and I agreed not to open ETMY. Since we had briefly opened the IOO and Output Optics chambers to check the X green's position on the PSL table, we immediately shut those doors. They were probably open for ~15 minutes or so. (Yes Steve, we should have checked before opening any doors, but at least we remembered to check at all, and the doors were only open for a few minutes rather than for a few hours.)
I attach a 24hrs trend of the particle counts, for reference. It looks like it's been a little high for a while, but today it's really dirty in the air.
|
The east end particle count is 155K for 0.3 micron and 15K for 0.5 micron counts/cf min. In order to minimize diffusion of dirt into the IFO we set up the mobile HEPA with CP Stat 100 tent.
This set up gives us practically ZERO inside the tent |
Attachment 1: P1080149.JPG
|
|
Attachment 2: P1080150.JPG
|
|
5148
|
Tue Aug 9 02:27:54 2011 |
Ishwita , Manuel | Update | PEM | Power spectra and Coherence of Guralps and STS2 |
We did offline wiener filtering on 3rd August (Elog entry) using only Guralps' channels X and Y.
Here we report the Power spectrum of the 3 seismometers (Guralp1, Guralp2, STS1) during that time.
and also the coherence between the data from different channels of the 3 seismometers.
We see that the STS is less correlated with the two Guralps. We think it is due to the wrong alignment of the STS with the interferometer's axes.
We are going to align the STS and move the seismometers closer to the stacks of the X arm.





|
5168
|
Wed Aug 10 12:28:22 2011 |
Ishwita , Manuel | Update | PEM | AA board gain |
We used a function generator, an oscilloscope and the Data Viewer to check the gain of the new AA board (used for the seismometers). Putting a sine wave of 0.3V (using a function generator) to the AA board, we could see about 500 counts in the Data Viewer. The calibration of the ADC is 214 counts/volt, so the AA board gives to the ADC an output of 0.03V. This proves that the AA board has a gain of 0.1. Guralp1 and STS1 (Bacardi), both have a gain of 10 now, that balance the AAboard gain of 0.1. If we consider the gain of AA board in our calibrated power spectrum plot of seismic signals from Guralp1 and STS1 (Bacardi), we get the following plot:

|
5170
|
Wed Aug 10 12:33:34 2011 |
Manuel, Ishwita | Summary | PEM | Weekly summary |
We got the results of the wiener filtering simulations (Elog Entry)
We got the power spectra and coherence of the seismic noise measurements from GURALPs and STS seismometers (Elog Entry)
We tried to whiten the target and the input signal for the computation of the wiener filter for the real data, but the results are unsatisfactory. We should not care about high frequencies in wiener filter computation so we will just filter them off in the filter output with a low pass filter.
We just found the right gain for the system seismometer-AAboard-ADC (Elog Entry) |
5171
|
Wed Aug 10 13:52:23 2011 |
Manuel , Ishwita | Update | PEM | Moving Seismometers |
We turned off the power of the seismometers and moved the Guralp1 close to the STS. Both are now situated below the center of the mode cleaner vacuum tube.
We oriented the X axis of the STS & Guralp1 along the X axis of the interferometer. Then we turned on the power again, but the STS channels don't give any signal. We think this is, because we didn't push the auto zero button. |
5172
|
Wed Aug 10 14:27:39 2011 |
Ishwita , Manuel | Update | PEM | Calibration of Guralp and STS2 |
ADC: 216counts = 4V Hence, calibration of ADC is 214counts/V.
Gain of the AA board, g1 = 0.1
GURALP
Sensitivity = 800 V/ms-1
214 counts/V x 800 V/ms-1 = 13107200 counts/ms-1 -----> 7.6294e-08 ms-1/count
Gain, g2 = 10
Calibration = 7.6294e-08 ms-1/count x g1 x g2 = 7.6294e-08 ms-1/count
STS
Sensitivity = 1500 V/ms-1
214 counts/V x 1500 V/ms-1 = 24576000 counts/ms-1 -----> 4.069e-08 ms-1/count
Gain of the STS electronic breakout box, g3 = 10
Calibration = 4.069e-08 ms-1/count x g1 x g3 = 4.069e-08 ms-1/count |
5174
|
Wed Aug 10 14:35:39 2011 |
rana | Update | PEM | Calibration of Guralp and STS2 |
I'm pretty sure that don't have any ADC's with this gain. It should be +/- 10V for 16 bits. |
5175
|
Wed Aug 10 15:17:39 2011 |
Ishwita, Manuel | Update | PEM | Calibration of Guralp and STS2 |
Quote: |
I'm pretty sure that don't have any ADC's with this gain. It should be +/- 10V for 16 bits.
|
Jenne told us that the ADC was +/- 2V for 16 bits so our calibration is wrong. Since, the ADC is +/- 10V for 16 bits we need to change our calibration and now we can also use the purple STS breakout box. |
5185
|
Thu Aug 11 09:39:25 2011 |
Ishwita, Manuel | Update | PEM | Calibration of Guralp and STS2 |
Quote: |
Quote: |
I'm pretty sure that don't have any ADC's with this gain. It should be +/- 10V for 16 bits.
|
Jenne told us that the ADC was +/- 2V for 16 bits so our calibration is wrong. Since, the ADC is +/- 10V for 16 bits we need to change our calibration and now we can also use the purple STS breakout box.
|
New calibration for Guralp:
ADC: 216counts = 20V Hence, calibration of ADC is (215x0.1) counts/V.
GURALP
Sensitivity = 800 V/ms-1
(215 x 0.1) counts/V x 800 V/ms-1 = 2621440 counts/ms-1 -----> 3.8147e-07 ms-1/count
Calibration = 3.8147e-07 ms-1/count
Using the above calibration we obtain the following plot:

When we compare this plot with the old plot (see here) we see that in our calibration, we have got a factor of 10 less than the old plot. We do not know the gain of the Guralp. If we assume this missing 10 factor to be the gain of Guralp then we can get the same calibration as the old plot. But is it correct to do so? |
5186
|
Thu Aug 11 10:56:08 2011 |
Ishwita, Manuel | Update | PEM | Moving Seismometers |
Quote: |
We turned off the power of the seismometers and moved the Guralp1 close to the STS. Both are now situated below the center of the mode cleaner vacuum tube.
We oriented the X axis of the STS & Guralp1 along the X axis of the interferometer. Then we turned on the power again, but the STS channels don't give any signal. We think this is, because we didn't push the auto zero button.
|
After pressing the auto-zero button (a lot of times) of the STS breakout box & aligning the bubble in the STS, we could finally get data from STS (Bacardi). So, now STS2 (Bacardi - Serial NR. 100151) is working! |
5187
|
Thu Aug 11 11:50:56 2011 |
Manuel , Ishwita | Update | PEM | Calibration of Guralp and STS2 |
We just checked with a function generator the calibration of the ADC. We set a square wave with amplitude 1V. We measured the voltage with the oscilloscope and we found on the data viewer that one volt is 3208 counts. That's what we expected (+/- 10V for 16bits) but now we are more sure.
|
5190
|
Thu Aug 11 13:41:36 2011 |
Ishwita, Manuel | Update | PEM | Coherence of Guralp1 and STS2(Bacardi, Serial NR 100151) |
Following is the coherence plot obtained when Guralp1 and STS2(Bacardi, Serial NR 100151) are placed very close to each other (but they aren't touching each other):

The seismometers were placed as shown in the picture below:

They are placed below the center of the mode cleaner vacuum tube. |
5196
|
Thu Aug 11 16:15:59 2011 |
Ishwita, Manuel | Update | PEM | Calibration of Guralp and STS2 |
Finally, we have found the correct calibration of Guralp and STS2 seismometers.
ADC: 216counts = 20V Hence, calibration of ADC is 3.2768e+03 counts/V.
GURALP
Sensitivity of seismometer = 800 V/ms-1
Gain of the guralp breakout box (reference elog entry) = 20
Calibration = 3.2768e+03 counts/V x 800 V/ms-1 x 20 = 52428800 counts/ms-1 -----> 1.9073e-08 ms-1/count
STS
Sensitivity = 1500 V/ms-1
Gain of the STS electronic breakout box = 10
Calibration = 3.2768e+03 counts/V x 1500 V/ms-1 x 10 = 49152000 counts/ms-1 -----> 2.0345e-08 ms-1/count
|
5197
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Thu Aug 11 16:21:16 2011 |
Ishwita , Manuel | Update | PEM | Power spectra and Coherence of Guralps and STS2 |
Following is the power spectrum plot (with corrected calibration [see here]) of seismometers Guralp1 and STS2(Bacardi, Serial NR 100151):

The seismometers are placed approximately below the center of the mode cleaner vacuum tube. |
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Thu Aug 11 19:14:22 2011 |
Ishwita , Manuel | Update | PEM | Seismometer STS2(Bacardi, Serial NR 100151) moved near ETMX |
We moved the STS2(Bacardi, Serial NR 100151) to his new location and laid his cable from rack 1X7 to ETMX. The seismometer was below the mode cleaner vacuum tube before.
Now, (since 6:05pm PDT) its placed near the ETMX.
 
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Fri Aug 12 00:18:30 2011 |
Ishwita, Manuel | Update | PEM | Coherence of Guralp1 and STS2(Bacardi, Serial NR 100151) |
We moved the seismometer STS2(Bacardi, Serial NR 100151) as we told in this Elog Entry, so the distance between Guralp1 and STS2 is 31.1m. Following is the coherence plot for this case:

then we also moved the Guralp1 under the BS and plugged it with the Guralp2 cable (at 7:35pm PDT), so now the distance between the two seismometers is 38.5m. Following is the coherence plot for this case:

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Fri Aug 12 17:05:22 2011 |
Manuel, Ishwita | Configuration | PEM | STS2 Cable configuration |
The WWF_M connector is the end of the STS2 seismometer orange cable and the S1 connector is the end of the gray 26-pin-cable

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Thu Sep 8 13:20:07 2011 |
steve | Update | PEM | vac envelope at atm for 36 days |
We tried not to open chambers above 10,000 particles of 0.5 micron cf/min
New items going in: 2 rasor beam traps, 5 badly oxidized old silver plated setscrew with spring loaded tips......to be replaced in the future, viton tips for eq screws....some are lose, gold plated allen wrench installed at ITMX bottom, reglued magnet on ITMX
Bad hardware things found: nylon ball "locking elements" on OSEM locking set screws with screwdriver slot, lose 1064 nm filter on OSEM pd |
Attachment 1: vent70.jpg
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Wed Sep 14 15:05:52 2011 |
steve | Update | PEM | air cond maintenance |
Jeff has changed our AC filters inside the lab this morning. Now he is checking on the main filters at CES. He will finish the roof units tomorrow.
Met One #1 counter is on the top of IOO chamber. It is measuring 1 and 0.5 micron size particles. One year of lab condition plot below.
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Attachment 1: ac1y.jpg
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Wed Sep 28 18:39:50 2011 |
Mirko | Update | PEM | BLRM seismic channels in c1pem |
[Mirko,Jenne]
Created 5-band BLRMS for seismometer data (Gur1, Gur2 and STS1 each in x,y,z respectively) and accelerometer 1 through 6.
Bands are:
0.1Hz-0.3Hz
0.3Hz-1Hz
1Hz-3Hz
3Hz-10Hz
10Hz-30Hz
each with a fitting 4th order butterworth bandpass.
Data is recorded at 256Hz as e.g. C1:PEM-ACC1_RMS_RMS_0p3_1_OUT_DQ. For the 75 channels we have that corresponds to the data rate of just 1.2 16kHz channels.
c1pem execution time increased fom 6-7us to 15-16us out of 480us available. |
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Wed Oct 19 15:48:20 2011 |
Mirko | Update | PEM | Moved the STS1 from x-arm end to vortex |
[Jenne, Mirko]
We moved our one STS1 from the x-arm end to the vortex. We record the data as STS1 in c1pem @ 256Hz. x is still north-south.
JD: This is actually an STS-2. We just call it C1:PEM-SEIS_STS1.... to differentiate the 3 STSs that we have from one another (assuming we plug in the other two).
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Wed Nov 23 02:34:28 2011 |
Mirko | Update | PEM | Seismic spectrum & Striptool |
The Striptool for the BLRMS seismic channels is running now. Channels are ( still ) recorded as slow EPICS channels.
A big peak in the 0.1 - 0.3Hz seismic region in both GUR1 and STS1 irritated us for a while. I added an extra LP filter @ 0.05Hz to the RMS_LP modules.

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Thu Dec 1 11:25:10 2011 |
steve | Update | PEM | 40m infrastructure holds up well in strong wind condition |
Santa Anna wind speed was locked around 60 kmph last night on campus. The strongest in 30 years. The lab hold up well. We did not lose AC power either.
Threes and windows were blown out and over on campus.
We have 4 sliding glass windows without "heavy-laser proved" inside protection.
We should plan to upgrade ALL sliding glass windows with metal protection from the inside.The strongest in 30 years. |
Attachment 1: santaannawind.png
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Attachment 2: wind.png
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Tue Dec 20 15:49:21 2011 |
steve | Update | PEM | optical table top |
3/4 " thick colored acrylic material will be used in this air tight design. Surgical tubing for o-ring. We may have to put an o-ring into the bottom to have it really air tight.
Feedtrouhs: www.roxtec.com
The top drawing is not ready. It will have handle and industrial grade L-handle lock pin to hold cover down. There will be 2 one inch od post in the midle of the table to hold the cover and lock the ball pin.
I'm waiting for your inputs, so I can send this preliminary design out for quote.
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Attachment 1: 05150901.PDF
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Thu Jan 12 10:11:59 2012 |
steve | Update | PEM | optical table top with 1" wall |
Quote: |
3/4 " thick colored acrylic material will be used in this air tight design. Surgical tubing for o-ring. We may have to put an o-ring into the bottom to have it really air tight.
Feedtrouhs: www.roxtec.com
The top drawing is not ready. It will have handle and industrial grade L-handle lock pin to hold cover down. There will be 2 one inch od post in the midle of the table to hold the cover and lock the ball pin.
I'm waiting for your inputs, so I can send this preliminary design out for quote.
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The present plan to go with clear cast acrylic plexiglass 1" thick side wall and two clear 1/2 thick top cover.
The inside would be lined with light braun YAG safety window sheets 0.14" VLT ~25% OD 4 @ 532nm & OD 5 @ 1064nm
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Attachment 1: 101122012atc.PDF
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