ID |
Date |
Author |
Type |
Category |
Subject |
480
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Thu May 15 14:39:33 2008 |
Caryn | Summary | PEM | filtering mode cleaner with mic |
Tried filtering for mode cleaner data(C1:IOO-MC_L) using a siso-firwiener filter and microphone data(C1:PEM-AS_MIC) for noise input. The noise reduction in mode cleaner data using the microphone-filter is comparable to the noise reduction when an accelerometer(C1:PEM-ACC_MC1_X) filter is used. See attached graphs. |
Attachment 1: MC_L_with_PEM-AS_MIC_filter.pdf
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Attachment 2: MC_L_with_PEM-ACC_MC1_X_filter.pdf
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518
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Wed Jun 4 16:25:06 2008 |
Caryn | Summary | PEM | microphone moved |
The microphone 'C1:PEM-AS_MIC' has been moved right a bit. This change didn't seem to have much effect on filtering the 'C1:IOO-MC_L' signal, at least not compared to how the filter changes with time. Also used microphone data to filter MC_L data using firwiener filter/levinson. The N(order) and sample rate were varied to see how the filter changed. Attached are graphs of the max(rms(noise_estimate)) vs N or IR for varying srate. Note that filtered_signal=signal-noise_estimate. So, the larger the noise_estimate, the more the filter subtracts from the signal.
Green-filtered signal
blue-noise estimate
red-MC_L signal
note decreasing sample rate is more effective than increasing N (higher N takes more time to compute)
note sample rate doesn't change the max(rms(noise_estimate)) very much if impulse response time remains constant
note the 64hz, N=7000 (impulse response about 110s) filter is a better filter than the 512Hz, N=7000(impulse response about 14s) |
Attachment 1: 1_MC_L.pdf
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522
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Fri Jun 6 11:19:13 2008 |
Caryn | Summary | PEM | Filtering MC_L and MC_F with PEM:ACC and microphone |
Tried to filter MC_L and MC_F with acc/seis data and microphone data using wiener filter (levinson)
-Used get_mic_data.m and miso_filter_lev.m to make SISO filter for 2 minutes of IOO-MC_F data. Used PEM-AS_MIC signal as noise input data. Filters calculated at initial time were applied to later data in 1 hour intervals.
-microphone filter did not seem to filter MC_F very well in high frequency range using this filtering procedure.
-residual is larger than est (see MC_F pdf)
-Used do_all_time_lev.m to make graph of max(rms(residual)) to N(order) for different times.(note for each N, filter was calculated for initial time and then applied to data at other times).
-relation of max(rms(residual)) to N(order) is time sensitive (note-on graph, time interval is 1hour) (see MC_F pdf)
-Presumably, max(rms(residual)) should decrease as N increases and increase as time increases since the filter probably becomes worse with time. I think the reason this isn't always true in this case is that the max(rms(residual)) corresponds to a peak (possibly a 60Hz multiple) and the wiener filter isn't filtering out that peak very well.
-Used get_z_data.m and miso_filter_lev.m to make MISO filter for 2 minutes of IOO-MC_L used the following signals as noise input data
PEM-ACC_MC1_X
PEM-ACC_MC2_X
PEM-ACC_MC1_Y
PEM-ACC_MC2_Y
PEM-ACC_MC1_Z
PEM-ACC_MC2_Z
PEM-SEIS_MC1_Y
-Filter was applied to later data in 2hour intervals.
-Used do_all_time_lev.m to make graph of max(rms(residual)) to N(order) for different times.(note for each N, filter was calculated for initial time and then applied to data at other times).
-acc/seis filter seemed to filter MC_L OK for 128,256,512Hz srates. 64 Hz wasn't ok for certain N's after a period of time.
-residual is smaller than est for srates not 64Hz (see MC_L pdf)
-residual is larger than est for 64Hz at N=1448 for later times (see MC_L pdf)
-relation of max(rms(residual)) to N is not as time sensitive for higher sample rates (note-on graph, time interval is 2hours) (see MC_L pdf). Perhaps the levinson 64Hz sample rate filter doesn't do as well as time passes for these signals. When the filter didn't do well, the max(rms(residual)) seemed to increase with N.
-For 512Hz sample rate filter the max(rms(residual)) decreased with time. If the max(rms(residual)) were an indication of filter performance, it would mean that the 512Hz filter calculated at the initial time was performing better later as hours passed by! Perhaps max(rms(residual)) isn't always great at indicating filter performance.
Programming notes
-I had to modify values in do_all_time_lev.m to get the program to loop over the srates,N's,times I wanted
-do_all_time_lev.m is not as clean as do_all_lev.m
-for making the plots do_all_lev.m (which isn't really a procedure and is messy) has some examples of how to plot things from do_all_time_lev.m. |
Attachment 1: MC_F.pdf
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Attachment 2: MC_L.pdf
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Attachment 3: miso_filter_lev.m
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function [s] = miso_filter_lev(N,srate,rat,z)
%MISO_FILTER_LEV(N,srate,z) uses miso_firlev to get levinson
% FIR Wiener filter of order N-1, using impulse response of
% N/srate. z is a structure gotten from the get_data function.
% z(end) is the signal which is filtered using z(i) for all i.
% 'rat' is the fraction of z which will be put into filter
% funtion. The data from z is downsampled using srate and
% detrended. Let rat=1. I don't have that part working yet.
... 107 more lines ...
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Attachment 4: get_mic_data.m
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function[z,t0,duration]=get_mic_data(t,d_t,d)
%get_mic_data gets data for'C1:IOO-MC_F', 'C1:PEM-AS_MIC,
% Example: z = get_mic_data('now',120,60)
% start time is 't- d_t' so d_t should be given in seconds. t should be given
% as a number like 893714452. d is duration in seconds. get_mic_data saves
% data to a file in current directory named 'temp_mic'. You will be asked to
% save file as 'mic_(start_time)_(duration)'.
duration = d;
... 32 more lines ...
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Attachment 5: do_all_time_lev.m
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function[r] = do_all_time_lev(n,t0,int,duration,N,srate,rat,order,time,MC_L,MC_F,sample_rate)
%do_all_time explores how filter performance changes with time, sample rate,
%and order of filter. Outputs data,noise estimate, structure of max
%rms error and other info. It uses get_data, miso_filter_lev, and miso_filter_int and retrives
%MC_Ldata or MC_Fdata for multiple times, calculates a miso_filter for initial-time data
%file, applies filter to the other data files, and keeps track of the...
%max(rms(residual)) for each filter. n+1 is number of data files. int is time interval between
%data files, t0 is start time, duration is duration of each data file, srate
%is the sample rate for which filter is calculated, n_N is number of orders
%of the filter you want the program to calculate,int_N is interval by which N
... 215 more lines ...
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Attachment 6: do_all_lev.m
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function[r] = do_all_lev(n,t0,int,duration,n_N,int_N,n_srate,int_srate,rat,MC_L,MC_F)
%do_all_lev explores how filter performance changes with time, sample rate,
%and order of filter. Outputs data,noise estimate, structure of max
%rms error and other info. It uses get_data, miso_filter_lev, and miso_filter_int and retrives
%MC_Ldata or MC_Fdata for multiple times, calculates a miso_filter for initial-time data
%file, applies filter to the other data files, and graphs the rms of the cost
%function vs time. n+1 is number of data files. int is time interval between
%data files, t0 is start time, duration is duration of each data file, srate
%is the sample rate for which filter is calculated, n_N is number of orders
%of the filter you want the program to calculate,int_N is interval by which N
... 283 more lines ...
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Attachment 7: do_all_plot.m
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function[r] = do_all_plot(r,x,v)
%do_all_plot plots variables contained in r(structure from
%do_all_time_lev).Plots error(r.B.y) vs x. x can be
%'s'(srate),'N'(order),'t'(time),'p'(impulse response). v can be 's','N','t'.
%example: do_all_plot(r,'s','t') makes a plot of error vs srate for
%different times.
kk=1
err_N_srate=0
... 388 more lines ...
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Attachment 8: miso_filter_int.m
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function [s] = miso_filter_int(s,y)
%miso_filter_int inputs a filter and a structure array of data sets y, applies filter to data, and
%outputs a structure with fields: ppos(signal frequ spectrum),perr(cost
%function frequ spectrum),pest(signal estimate frequency
%spectrum),f(frequency),target(signal),est_darm(noise estimate),t(time).
%data file for which filter has been calculated is s (obtained using miso_filter).
%y consists of data structures which will be filtered using
%filter from s. Then the power spectrum of the difference between signal and filtered-data is
%graphed for all the data files of y for comparison too see how well filter performs
%over time. Note if you want to create a y, take z1,z2,z3,etc. structures
... 120 more lines ...
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547
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Fri Jun 20 01:38:55 2008 |
rana | Update | PEM | 20 day Weather |
Yoichi showed me that its possible to make PNG images from PS using GS:
gs -sDEVICE=png16m -sOutputFile=foo.png bar.ps |
Attachment 1: test.png
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571
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Thu Jun 26 01:10:18 2008 |
rana | Update | PEM | Alarm Handler indicates that dust level is high |
In its first useful act, the Alarm Handler started beeping indicating that the dust particle
counts for particles of diameter less than 0.5 micron had exceeded 5000 /cu. ft. Here's the
80 day trend of particles, temperature and humidity: |
Attachment 1: Untitled.png
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572
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Thu Jun 26 10:56:15 2008 |
Max Jones | Update | PEM | Removed Magnetometer |
I removed the Bartington Magnetometer on the x arm to one of the outside benches. I'll be trying to determine if and how it works today. It makes a horrible high pitched sound which is due to the fact that the battery is probably 16 yrs old. It still works with ac power though and I want to see if it is still operating correctly before I ask to buy a new battery. Sorry for the bother. |
581
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Fri Jun 27 09:20:15 2008 |
steve | Frogs | PEM | dust particle count is up & alarm handler is on |
This 3 years plot show the trend of seasons.
When outside air quality goes bad ( 0.5 micron > 1 million ) the lab follows.
I will demonstrate this effect with a 4th of July fire works calibration.
Let's do not forget the construction activity next door either.
The alarm handler is busy:
It's sound level were reset to a modest level yesterday.
It would be nice to change the alarm sound so it can play Wagner:Der Ring des Nibelungen:
Das Rheingold, Die Walkure & Siegfried and Gotterdammerung
or something more appropriate than the present frog call
1, half micron count is climbing ( it's close to 16k now )
2, MZ refl signal is too high
3, MC lenght servo LO is too |
Attachment 1: dust3y.jpg
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640
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Mon Jul 7 13:58:37 2008 |
Eric, josephb | DAQ | PEM | Using unused PEM channels to test camera code |
Joe and I have taken control of the EPICS channels C1:PEM-Stacis_EEEX_geo and C1:PEM-Stacis_EEEY_geo since we heard that they are no longer in use. We are currently
using them to test the ability for the Snap camera code to read and write from EPICS channels. Thus, the information being written to these channels is completely unrelated
to their names or previous use. This is only temporary; we'll create our own channels for the camera code shortly (probably within the next couple of days).
- Eric |
646
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Tue Jul 8 10:20:10 2008 |
steve | Update | PEM | HEPA turned on |
It is specially important to run the PSL-HEPA filters when inside counts is peaking at 30,000 counts
There is a small label at the hepa on/off switch:
enclosure open 100%,
low noise off,
normal 60% of Variac voltage setting on the top of the enclosure
Not running the HEPAs will lower the temp fluctuations from 1.5 to o.5 degree C
at the cost of particle counts from 0 to immidiate room counts. |
Attachment 1: hepa.jpg
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670
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Tue Jul 15 09:47:09 2008 |
steve | Update | PEM | lab temps and particles |
All air condtion units were serviced last Friday.
AC filters are trying to control our particle counts but they have no capacity to match bad Pasadena conditions.
IFO room filters at CES were really clean.
Air make up filters inside and outside were dirty.
They showed the construction effect.
Control room and clean assembly units needed all filters replaced.
Note: the PSL-FSS_RCTEMP droped o.1C when enclouser HEPAs were turned back on
The RC temp controller should be better than that! |
Attachment 1: temps24d.jpg
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673
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Tue Jul 15 11:47:56 2008 |
Jenne | DAQ | PEM | Accelerometer channels in ASS Adapt MEDM screen |
Jenne, Sharon
We have traced which accelerometers correspond to which channels in the C1ASS_TOP MEDM screen.
Accelerometer Channel
------------- --------------------------
MC1-X C1:ASS-TOP_PEM_2_ADAPT_IN1
MC1-Y C1:ASS-TOP_PEM_3_ADAPT_IN1
MC1-Z C1:ASS-TOP_PEM_4_ADAPT_IN1
MC2-X C1:ASS-TOP_PEM_5_ADAPT_IN1
MC2-Y C1:ASS-TOP_PEM_6_ADAPT_IN1
MC2-Z C1:ASS-TOP_PEM_7_ADAPT_IN1
SEISMOMETER C1:ASS-TOP_PEM_1_ADAPT_IN1 |
705
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Mon Jul 21 10:00:42 2008 |
steve | Update | PEM | ifo room temp |
Five years of temp trend with 5 C fluctuation. The campus chilled water supply was upgraded ~ 1 year ago.
I requested our thermostats to be calibrated. |
Attachment 1: temp5y.jpg
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707
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Mon Jul 21 14:26:11 2008 |
Max | Summary | PEM | Added Channels |
The following channels have been added.
Channel Name DAQ port
C1 : PEM-MAG_BSC_X 27
C1 : PEM-MAG_BSC_Y 28
C1 : PEM-MAG_BSC_Z 29
Jenne and I ran the wires from near the beam splitter chamber (as described in a previous elog) to the rack Y7 and plugged the labeled BNC's into ports 27-29. The computer was c0dcu1. John then restarted the frame builder and Alberto and I restarted the front end of c0dcu1 as per the wiki's instructions. The channels seem to be working. - Max. |
786
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Sun Aug 3 20:53:54 2008 |
rana | Configuration | PEM | Guralp |
We got our repaired Guralp back in the mail from England (s/n T4157). I plugged it in
to Ben's 3-Guralp breakout box (http://www.ligo.caltech.edu/docs/D/D060506-00.pdf) and
verified that it is not oscillating (like it was before) and that it responds to us
jumping around.
The breakout box has way too much gain, however. The ADC wants +/-2 V and the box puts out
~5 Vpk in the night time.
Looking at the schematic, it has a DC gain of 200 and a double whitener (50,50:10,10) so that
there's a gain of 5000 from 50-2000 Hz. The Guralp has a transduction gain of 800 V/(m/s) and
so we can just calculate what the frequency dependent noise figure of the box has to be. I've
pulled it out, put it on the bench, and started reworking it. I am looking for a soldering/
testing volunteer.
The other kink in the problem is that since we want to use this for the adaptive noise cancellation,
we have to make the noise floor of the readout better than the ambient noise by the same factor
with which we want to cancel the noise. |
820
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Mon Aug 11 00:58:31 2008 |
rana | Update | PEM | 2 years of temperature trend |
The PSL RMTEMP alarmed again because it says the room temperature is 19.5 C. Steve said in
an earlier log entry that this is a false alarm but he didn't say why he thought so...
I say that either the calibration of the RMTEMP channel has drifted, the setpoint of the HVAC
has shifted, or there's a drift in the RMTEMP channel. I don't know what electronics exactly
are used for this channel so not sure if its susceptible to so much drift.
However, since the Dust Monitor (count_temp) shows a similar temperature decline in the
last two years I am inclined to blame the HVAC system.
The attached plot shows 2 years of hour-mean trend. |
Attachment 1: Untitled.png
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821
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Mon Aug 11 09:39:29 2008 |
rana | Update | PEM | 2 years of temperature trend |
Steve and I went around and inspected and then adjusted the thermostats and humidostats.
All the thermostats were set at 70F in 2005 by Steve. We adjusted the ones on the arms up to 72F
and set the one on the wall west of the framebuilder up to 74F (this area was consistently colder
than all the others and so we're over-correcting intentionally). |
826
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Mon Aug 11 19:09:28 2008 |
Jenne | DAQ | PEM | Seismometer DAQ is being funny |
While looking at the Ranger seismometer's output to figure out what our max typical ground motion is, Rana and I saw that the DAQ output is at a weird level. It looks like even though the input to the DAQ channel is being saturated, the channel isn't outputing as many counts as expected to Dataviewer.
Sharon and I checked that the output of the seismometer looks reasonable - sinusoidal when I tap on the seismometer, and the the output of the SR560 (preamp) is also fine, and not clipping. If I stomp on the floor, the output of the SR560 goes above 2V (to about 3V ish), so we should be saturating the DAQ, and getting the max number of counts out. However, as you can see in the first figure, taken when I was tapping the seismometer, the number of counts at saturation is well beneath 32768counts. (16 bit machine, so the +-2V of the DAQ should have a total range of 65536. +2V should correspond to +32768counts.) The second figure shows 40 days of seismometer data. It looks like we saturate the DAQ regularly.
I did a check of the DAQ using an HP6236B power supply. I sent in 1V, 2V and 2.2V (measuring the output of the power supply with a 'scope), and measured the number of counts output on the DAQ.
Input Voltage [V] | Counts on Dataviewer | Expected counts from 16 bit machine
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1 | 18983 | 16384
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2 | 29331 | 32768
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2.2 | 29347 | 32768
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I'm not sure why the +1V output more than the expected number of counts (unless I mis-measured the output from the power supply).
Moral of the story is...when the DAQ is saturated, it is not outputting the expected number of counts. To be explored further tomorrow... |
Attachment 1: SeisDAQ.png
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Attachment 2: SeisData.png
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834
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Thu Aug 14 11:39:06 2008 |
steve | Update | PEM | particle counter is out of order |
The 40m ifo paricle counter sensor failed last night. |
853
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Tue Aug 19 14:25:38 2008 |
Sharon | Update | PEM | Accelerometer's calibration - update |
Goal - Make sure the accelerometers are calibrated among themselves (have the same power spectrum when they are all together reading the same movements).
What I did - took the accelerometers off their usual X Y Z setting and set the 3 MC2's and 3 MC1's next to each other covered by a box.
Then I brought MC2 X to MC1 X and placed them in a box so I have a referance between the 2 groups.
Result - Seems MC1 accelerometers are much alike and have the same power spectrum when placed together for all frequencies. MC2 accelerometers seem to do the same until approximately 30 Hz. (decided not to correct for that since we don't really care about the accelerometers in such high frequencies).
When comparing the 2 X's, they also seemed to be almost perfectly correlated. I chose the gain by dividing the two and finding the mean of that in the range of 2 to 30 Hz. After correcting for all the accelerometers, I matched the gains of each group to its X accelerometer.
You can see the plots, taking into consideration that the groups were never together (pretty messy getting the cables all around).
Here are the numbers, when the MC2 and MC1 gains are calculated by comparing them to their X direction.
gain MC1 X_over_MC2 X=
1.0870
gain_MC2_Y =
0.9944
gain_MC2_Z =
0.9479
gain_MC1_Y =
1.0394
gain_MC1_Z =
0.9149 |
Attachment 1: acccalibafter.png
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Attachment 2: acccalibbefore.png
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871
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Fri Aug 22 16:06:29 2008 |
steve | Update | PEM | particle counter replaced, flowbenches & HEPAs checked |
MetOne #2 counter was swapped in (on the top of IOC, facing SW direction, at ~75 deg upwards)
with channel one size 0.3 micron and channel two size 1.0 micron.
Sampling time was reduced from 60s to 6 sec at 0.1 cf/min at 25 min rate.
This means that displayed number needs to be multiplied by x100 to get particles/cf/min
HEPA filters and flow benches were checked:
PSL enclosure closed, HEPA speed at 60% 0-0 particles on optical table NW corner
AP covered optical table 1,000 particles of 0.3micron and 10 of 1.0 micron at NE corner
Flow bench at SE 0-0 particle (p)
on the top of SP cover at SE corner 60,000 p of 0.3 micron and 530 p of 1.0 micron
Mobile HEPAs 10cm from output screen in the center 800 p of 0.3 micron and 0 p of 1 micron
These filters will be replaced.
Clean assembly room:
both flow benches 0-0 p for 0.3-1.0 micron
east side bench 520 p of 0.3 micron and 210 p of 1.0 micron
Large hood in baking room with fan on 1.7 million p of 0.3 micron
and 16,000 p of 1.0 micron
Pasadena air just outside of main entrance:
3 million p of 0.3 micron and 30,000 p of 1.0 micron
My desk 743,000 p of 0.3micron, 63,000 p of 0.5 micron and 5,500 p of 1.0 micron cf/min
NOTE: existing COCHECKLIST.adl PEM displays needs to be corrected so it shows the 10 fold increase
and change particle size on this screen to 0.3 micron |
881
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Mon Aug 25 15:50:18 2008 |
rana | Summary | PEM | Ranger SS-1 |
The manual for the Ranger SS-1 seismometer can be found on line here:
ftp://ftp.kmi.com/pub/software_manuals/300190/300190nc.pdf
and now in our 40m PEM Wiki page:
Ranger_SS-1
To calibrate it, we use the formula from the manual:
R_x
G_L = G_0 * ------------ = 149 +/- 3 V/(m/s)
R_x + R_c
where
G_0 = 340 V/(m/s) (generator constant)
R_x = 4300 Ohms (external damping resistor in Pomona box)
R_c = 5500 Ohms (internal coil resistance)
Then we have a gain of 200 in the SR560 so that gets us to ~30000 V/(m/s).
And then there's a DAQ conversion factor of the usual 2^16 cts / 4 V.
so the calibration constant is
G = 488 counts / (micron/sec)
in the ~1-50 Hz band |
882
|
Mon Aug 25 17:45:34 2008 |
rana, josephb, rob | HowTo | PEM | Accelerometer range |
Joe shows us by jumping up ~15" in the control rom that the accelerometers are set with not enough gain.
Since this is taken around 5:30 in the evening, so we can take the nearby time series to represent what a
high noise level is. I recommend we up the gain using the ICS-110B .ini file. |
Attachment 1: Screenshot-4.png
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886
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Tue Aug 26 12:00:45 2008 |
Jenne | Summary | PEM | Transfer function of Ranger seismometer |
This finishes up the calibration that Rana started in elog # 881.
The calibration of the Ranger seismometer should also include:
2 zeros at 0 Hz
2 poles at 1.02 Hz
This comes from finding the transfer function between the mass's motion and the motion of the ground.
..
m * x = (x_G - x) * k + d(x_G - x) * b
dt
where
- m = mass
- x = displacement of the mass
- x_G = displacement of the ground
- k = spring constant
- b = damping constant
This gives
x w0^2 + i*w*w0/Q
---- = -----------------------
x_G w0^2 + i*w*w0/Q - w^2
where
- w0 = sqrt(k/m) = natural frequency of spring + mass
- w = frequency of ground motion
- Q = q-factor of spring + mass system = 1/2 for critically damped system
The readout of the system is proportional to
d (x - x_G) ( w0^2 + i*w*w0/Q ) . w^2 .
dt = ( ----------------------- - 1 ) * x_G = ----------------------- * x_G
( w0^2 + i*w*w0/Q - w^2 ) w0^2 + i*w*w0/Q - w^2
Since we read out the signal that is proportional to velocity, this is precisely the transfer function we're looking for. With w0 = 1.02 Hz and Q = 1/2 for the critically damped system, we have 2 zeros at 0 and 2 poles at 1.02. |
930
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Thu Sep 4 18:02:34 2008 |
rana, josephb | Configuration | PEM | Accelerometer gains increased by 10 |
We increased the Accelerometer gains by 10 by modifying the C1ADCU_PEM.ini file.
[C1:PEM-ACC_MC1_X]
chnnum=15014
gain = 10
etc.
The plot shows the before and after for one channel. The ADC noise floor is ~10^-2 counts/rHz in this plot so now
we can do much better noise subtraction. |
Attachment 1: acc.png
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933
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Fri Sep 5 10:36:34 2008 |
steve | Update | PEM | thermostate setting changed |
Some one changed the thermostat (old control room ) setting behind 1Y6 from 73 to 79F
It should be in the elog.
The temp changed from freezing 20 to sunny 25 C |
934
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Fri Sep 5 15:09:50 2008 |
rana | Update | PEM | thermostate setting changed |
Quote: | Some one changed the thermostat (old control room ) setting behind 1Y6 from 73 to 79F
It should be in the elog. |
In fact, it is. I demand satisfaction for the injury to my elogging reputation! |
936
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Mon Sep 8 13:47:35 2008 |
steve | Update | PEM | thermostate setting changed |
Quote: |
Quote: | Some one changed the thermostat (old control room ) setting behind 1Y6 from 73 to 79F
It should be in the elog. |
In fact, it is. I demand satisfaction for the injury to my elogging reputation! |
Thermostate setting was changed from 79F to 77F behind 1Y6 |
949
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Tue Sep 16 10:57:45 2008 |
Yoichi | Configuration | PEM | Particle counter gain |
Summary:
Since we reduced the integration time of the particle counter by a factor of 10, we had to add a gain of 10
to the EPICS channels C1:PEM-count_full and C1:PEM-count_half.
I asked Alex to change it and he did it. I forgot to ask him to change the gain of C1:PEM-count_half. So now only
C1:PEM-count_full has x10 gain.
Detail:
C1:PEM-count_full and C1:PEM-count_half are 'Soft Channel' records in the database (Pcount.db). The values are actually
written into the VAL fields directly by an SNL code Particle.o.
Particle.o reads data from the RS-232C port, to which the particle counter is connected. Then it parses the data and put values
into relevant EPICS channels using channel access. This means we cannot change the gain of the channels by modifying the
database file. For example, ASLO field does not have any effect when the value is directly written into the VAL field.
We had to modify the SNL code. Alex modified Particle.st and the new SNL object file is Particle_x10.o sitting in
/cvs/cds/caltech/target/c1psl/. I modified seq.load so that c1psl loads Particle_x10.o when rebooted.
The source code for the old Particle.st can be found on lesath.ligo.caltech.edu in
/export/CDS/d/epics/apple/Caltech/40mVac/40mVacScipe/dev/src
I asked Alex to disclose the location of the source of the new code.
In order to compile the SNL code into an object file for Motorola CPU by ourselves, we have to call Dave Barker at LHO. |
950
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Tue Sep 16 13:04:22 2008 |
Yoichi | Configuration | PEM | C1:PSL-FSS_RMTEMP alarm level changed |
At the request of Steve, I modified the HIGH value of C1:PSL-FSS_RMTEMP from 21.27 to 23.0.
The HIHI is set to 23.50. |
1057
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Mon Oct 20 09:45:56 2008 |
steve | Update | PEM | PSL HEPA on |
The PSL HEPA filter was turned on.
It should be running all times.
The 0.5 micron particle count is up to 20,000 this morning. |
1089
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Fri Oct 24 21:49:15 2008 |
Jenne | Configuration | PEM | Short Seismometer Cable |
Bad news regarding the cable that goes between the Guralp seismometer and the box that I've been working on: it's too short by about a factor of 2. Dang it. I've placed the seismometer underneath the Beam Splitter Chamber (where it needs to go), and started running the cable toward the ADC rack where box was planned to go, and as Rana guessed earlier tonight, the cable isn't nearly long enough. We have some options: the seismometer can go back into the half-height rack near the BS, SRM, PRM oplev's optical table where I think it used to be, or it can go into the rack with the Kepco high voltage power supplies and the laser's supply. The cable won't reach any farther than that.
I think that we can just add BNC extensions onto the octopus cable that Bob made for the Guralp box, so all we need to figure out after we decide on a rack is the power for the box. |
1090
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Fri Oct 24 22:30:38 2008 |
Jenne,rana | Update | PEM | Noise from Guralp Seismometer |
Attached is a Power Spectrum of the noise on the Vert1 channel of the Guralp seismometer. The noise is in the several hundreds of nV/rtHz up near 50Hz and higher, but is in the several microV/rtHz range at lower frequencies. Our high frequency noise is almost definitely below the noise of the ADC, but the lower frequencies, where we actually care, it's not as clear.
To Do list:
- Measure the noise of the ADC - is the Guralp Box lower for all frequencies?
- Use conversion factors to convert this measured noise into the minimum ground motion that we can measure. Is this at least a factor of 100 lower than our regular ground motion?
** UPDATE: This is actually the noise of the Guralp breakout box, not the Guralp itself. It is the noise measured on the output of the box
with the input shorted. The board is configured to have a gain of 20 (10 from the AD620 and 2x for differential drive). We also measured
directly at the AD620 output and all of this noise comes directly from that chip. If Jenne calculates that this noise is too high we would
have to find a replacement with a better low frequency floor (e.g. LT1012 or LT1007 depending on the Guralps source impedance). |
Attachment 1: Vert1_Noise_24Oct2008.png
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1100
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Wed Oct 29 12:54:28 2008 |
Jenne | Update | PEM | Calibrated Guralp Noise compared to average ground motion |
Here is a calibrated noise plot of the Guralp seismometer box. This is the same noise measured on Friday, measured at TP3 (just after the first gain stage), with the inputs shorted.
The Guralp calibration is:
TP3 noise
noise in m/s = -------------------
10 * 802(V/(m/s))
The 10 is from the gain of 10 between the output of the seismometer and the input of the breakout box, and the 802 V/(m/s) is from the calibration data that came with the seismometer.
From elog 881 by Rana, in the ~1-50Hz band, the calibration of the Ranger seismometer is 488*10^6 counts/(m/s). Using DataViewer, I estimated that the nighttime ground motion measured by the Ranger is ~3500 counts, and the max daytime ground motion is ~8000 counts. This is what was used for the nighttime/daytime lines in this plot.
It seems like the noise of the Guralp box is fine just as it is, and we don't need to worry about replacing the first gain stage (differential instrumentation amp) with a lower-noise op-amp, since at even the lowest freqs, we have almost a factor of 100 at night, and better than that at higher freqs.
NOTE about the plot: the legend isn't showing the correct colors for the night and day motion - obviously the nighttime motion is the lower RED line, and the day is the higher GREEN line.
Yet another note: When I was measuring the counts on the Ranger, I forgot to subtract the mean, so these numbers are overestimating the ambient ground motion. The blue curve is correct however. |
Attachment 1: GuralpVert1Noise_mPERs_Ranger.png
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1102
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Thu Oct 30 20:39:47 2008 |
caryn | Configuration | PEM | temperature sensor |
We attached the temperature sensor box to the MC1/MC3 chamber with a C-clamp. We connected the temp sensor to a 2nd box with a short BNC. Bob set up a power cable coming from the X-end towards the MC1/MC3 chamber(Thanks, Bob!) We soldered the end of Bob's power cable to a plug and attached it to the 2nd box (The power supply enters through the 2nd box). A ~20ft BNC cable connects the output signal of the 2nd box to the tall thing by the PSL where all the signals go labeled 1Y2. Once we had everything connected, we put in the fuses for the power supply. So, now the temperature sensor is receiving power. We checked that the power supply was working (we measured +15.08V and -14.95V, and we wanted 15V and -15V so it's OK for now). Tomorrow we will modify C1IOOF.INI file and reboot the frame builder.
About sensor-
There is an LM34 (looks like a transistor) glued w/ epoxy and thermal paste to the inside of a Pomona box ~1"x"1.5"x2". The lid to the box is covered with a 1-2mm thick piece of copper and a little thermal paste is sandwiched between the Pomona lid and the copper piece. A C-clamp attaches the copper piece to the chamber. A BNC is connected to one side of the box (the side with less copper)
About power supply box-
There is a power regulator and an op-amp inside a Pomona box ~2.5"x4"x2". The power regulator is attached to the center of lid of the pomona box with a screw and washer. There's a power plug on the front of the box
Left:+15V:red wire
Center:GND:white wire
Right:-15V:black wire
There are 2 BNC connections on the sides of the box. The left BNC connection is for the output signal and the right BNC connection is for the temperature sensor (if the power plug is coming out of the box towards you).
Sensor location-
Chamber which contains MC1/MC3. On the door facing towards the Y-end. On the bottom-left side. Behind the door. Attached with a C-clamp.
Power supply box location-
Chamber which contains MC1/MC3. On some metal leg thing near the floor facing towards the Y-end. Attached with a zip-tie
Power supply-
Coming from the X-end from a tall thing with all the fuses labeled 1X1
Fuse 160:+15V:red wire
Fuse 171:GND:white wire
Fuse 172:-15V:black wire
Signal-
Going towards the PSL to the tall thing labeled 1Y1 on the rack labeled SN208
ICS-110B
J12 (which we believe corresponds to 50-51 and channel number 13650)
Temperature sensor is connected to J12 with a ~20ft BNC attached to a BNC2LEMO connector we found lying around |
1106
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Sun Nov 2 21:37:22 2008 |
rana | Update | PEM | Ranger recovery |
The ranger signal has been bad since around 11 AM on Oct 25 (last Saturday). There are no elog
entries from that day, but I am quite sure that someone must have been working around the PSL
rack area.
It looks like what happened is that someone moved the chair with the monitor on it and/or the wooden
stool next to it. That put tension on the cable connecting the SR560 and the seismometer. The SR560
connector now seems loose and I think probably the cable ground wasn't connected. I swapped the
cable over to the "B" side of the SR560 and the ranger signal is now reasonable (very small offset
and normal seismic signal).
Please be careful when working around there. Everyone always says "I didn't do anything" or "it doesn't
effect anything".
We need to clean up the cabling around there in addition to running a new power cable for the RF amplifier
on the POY table.
I have also reduced its sample rate from 2048 to 512 Hz. The data are OK after 909640694.
I also increased the sample rate of AS_MIC from 2048 to 16384 Hz but that one seems to be broken
---->> the microphone seems to be either disconnected or broken. |
1113
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Tue Nov 4 01:03:01 2008 |
rana | Summary | PEM | periodic thump noise in MC1_ACC |
There seems to be a periodic thump seen by the MC1 Accelerometers as well as the surrounding optics.
The first 5 hour minute-trend plot shows the periodic thumping as well as the one large saturating event which ruins the
Wiener noise subtraction.
The second plot is a 30 minute second-trend zoom in. |
Attachment 1: Untitled.png
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Attachment 2: Untitled2.png
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1120
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Fri Nov 7 08:08:00 2008 |
steve | Update | PEM | AC turned off in IFO room |
All tree AC units in IFO room 104 switched off at 7:45am
I'm looking for the periodic thump signal in the Vertex area
noted in entry 1113 of PEM-ACC_MC1 |
1121
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Fri Nov 7 10:52:57 2008 |
steve | Update | PEM | AC is back on |
The 20 minutes and 6 sec thumps are not related to the 40m ac units
This period is precisely right on so it is not likely mechanical as a source.
The time and frequency domain of this signal at attachment 2&3
First I had the chilling water cut off and later I turned off the fans
as 5 hrs temp plot shows |
Attachment 1: acf.jpg
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Attachment 2: acc_mc1.jpg
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Attachment 3: test.jpg
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1122
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Fri Nov 7 15:58:10 2008 |
rana | Update | PEM | AC is back on |
I'll bet Steve a dollar that it is mechanical. The attached PDF compares all of the accelerometers from right now.
You can see that the RMS in MC2 is way bigger than MC1.
In the second PDF file you can see the time series. I had to play around a lot with DTT to get it to work. The DTT/Foton
combo on Allegra is not stable, so make sure your work early and often.
In the plots shown, I am bandpassing the time series from 600-700 Hz. I found that doing so allowed the burp in MC1 to remain
large and reduce the extraneous fuzz in MC2. As you can see there is no such noise in MC2.
So its a noise around 600-700 Hz that comes on quickly and then shuts off after several seconds. Its also very periodic in that
it comes on around every 20 minutes. Steve also tells me (although he refuses to put in the elog) that it started up around
August 20th (?). I feel like someone in the 40m lab ought to be able to guess what this is at this point.
Please convince Steve to elog his findings about when the noise started.
If one goes out there and stands next to it when the trend predicts its happening it becomes clear what it is. |
Attachment 1: mc-acc.pdf
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Attachment 2: mc-acc-quad.pdf
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1127
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Mon Nov 10 16:44:14 2008 |
steve | Update | PEM | particle counter at MC2 |
The particle counter was moved to MC2 table temporarily.
It is clamped to the table at the south west corner.
It is pumping for 20s and waiting for 2 minutes now. |
1129
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Mon Nov 10 19:39:40 2008 |
steve | Update | PEM | thump noise from particle counter |
The particle counter is back on the IOOC location on a piece of FOAM
It needs this isolation, so when the pump is running, it's not shaking things.
The counter was counting for 6 sec and it was on holding for 20 mins.
Now I set the counter for 20 sec so it is easy to recognise it's signal and it holds for 2min only.
This will set the alarm handler in action.
Atm1: 40 mins plot
PEM-ACC_MC2_x,y,z up to 13 mins: pcounter at MC2 table, clamped, counting for 20s and holds for 2 mins
PEM-ACC_MC2_x,y,z from 13 to 26 mins: pcounter at MC2 table, not clamped, seated on 2" foam, counting 20s and holds for 2 mins
PEM-ACC_MC1_x,y,z from 26 to 40 mins: pcounter at MC1_IOOC location, not clamped, seated on 2" foam, counting 20s and holds for 2 mins
Rana won the bet
Quote: | I'll bet Steve a dollar that it is mechanical. The attached PDF compares all of the accelerometers from right now.
You can see that the RMS in MC2 is way bigger than MC1.
In the second PDF file you can see the time series. I had to play around a lot with DTT to get it to work. The DTT/Foton
combo on Allegra is not stable, so make sure your work early and often.
In the plots shown, I am bandpassing the time series from 600-700 Hz. I found that doing so allowed the burp in MC1 to remain
large and reduce the extraneous fuzz in MC2. As you can see there is no such noise in MC2.
So its a noise around 600-700 Hz that comes on quickly and then shuts off after several seconds. Its also very periodic in that
it comes on around every 20 minutes. Steve also tells me (although he refuses to put in the elog) that it started up around
August 20th (?). I feel like someone in the 40m lab ought to be able to guess what this is at this point.
Please convince Steve to elog his findings about when the noise started.
If one goes out there and stands next to it when the trend predicts its happening it becomes clear what it is. |
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Attachment 1: partcfm.jpg
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1131
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Wed Nov 12 11:36:13 2008 |
Jenne | Update | PEM | Guralp Breakout Box is ~50% hooked up |
The Guralp box is about halfway hooked up now. The seismometer is under the BSC, and the long cable from the seismometer to the breakout box is connected to "Guralps 1 Input" on the front panel. This corresponds to the set of 3 channels that Caryn stuffed with the new fancy-pants resistors few weeks ago. (When we finally get the other Guralp back from the company, we'll have to stuff the next set of 3 channels).
The Breakout Box is on the very top of 1Y1, sitting on top of the black power supplies. This should be fine, but it's pretty toasty hot up there, so if we find that there are problems with running the box at higher-than-room-temperature, step 1 will be to find a new spot for the box. (I'm not at this time anticipating a problem, but you never know....) Steve put a little foot between the Guralp box and the power supply to get some air circulation.
The ADC Octopus cable that Bob made is connected, and going up through the top of the rack. I am now going on a BNC cable hunt to extend this cable over to the PEM ADC. The PEM ADC is in 1Y7, so I'll need some medium-long BNC cable to get there.
The power cable is also ready to be connected to the rack's +/- 15VDC. I'll talk to Bob about getting this done.
Next step: pick some channels on the PEM ADC, and create them in the .ini files |
1141
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Mon Nov 17 16:59:22 2008 |
Jenne | Update | PEM | Seismometer hooked up, reading channels on DataViewer |
Alberto, Jenne
The Guralp Seismometer is (finally) hooked up to the PEM ADCU. Alberto helped me make channels in the c1pem1 .ini file, which correspond to:
Guralp1 VERT = channel 9 on PEM ADCU = C1:PEM-SEIS_MC1_VERT
Guralp1 NS = channel 10 on PEM ADCU = C1:PEM-SEIS_MC1_NS
Guralp1 EW = channel 11 on PEM ADCU = C1:PEM-SEIS_MC1_EW
We also renamed the Ranger seismometer's channel to C1:PEM-SEIS_MC2_Y from C1:PEM-SEIS_MC1_Y, since tomorrow I'll move the Ranger Seismometer to be underneath MC2's chamber (it's currently sitting somewhere in the middle of the Mode Cleaner).
I can see the VERT and NS channels with dataviewer, but EW looks dead. I need to figure out if this is a bad cable thing, or if the ADC channel is no good, or if something in the box on that channel is no good. All 3 channels were tested and working after all the soldering was completed by Caryn, but something may have come undone while putting the box into its new place in the top of 1Y1. (In dataviewer, it looks like the EW channel is just floating, and not connected to anything.)
Plan of Attack:
* figure out why EW looks dead on Dataviewer
* redo Rana's static Wiener filter analysis, now that we have 2 seismometers (1 Ranger and 1 Guralp)
* work on adaptive Wiener filtering with the Guralp |
1152
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Fri Nov 21 16:52:48 2008 |
Jenne | Update | PEM | Guralp seismometer's Channel Problems are solved |
PROBLEM noticed earlier this week: It looked like one of the seismometer channels (VERT-1) wasn't working, no matter how I put which channel into which input of the PEM ADCU. Watching the channel on Dataviewer, it looked like the ADC was measuring VERT-1 to be zero (actually measuring zero, not digital noise-type zero). I had checked the ADC by putting in a sine wave with a function generator, and saw on Dataviewer the wave I expected, so I knew that I had the correct channel, and that the channel was good.
SOLUTION: This afternoon I took the box out of the rack and opened it up. As soon as I opened it, I saw that I had left something inside the box which was causing the problem. Back when we were measuring the noise of the box, to ensure that it is lower than the ADC's noise, Rana and I had shorted the test points on the input of the VERT-1 channel with a little piece of wire. It turns out that I had closed up the box without remembering to remove the wire.
CONCLUSION of the story: I took out the piece of wire, and now all three seismometer channels (VERT-1, N/S-1, E/W-1) all work, and all detect me jumping around near the BSC. Since the seismometer breakout box reads a differential measurement, and since the input test points were connected, it was indeed measuring zero. Zero equals zero is all well and good, but it's even better now that it's measuring actual seismic motion. |
1153
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Fri Nov 21 17:27:47 2008 |
Jenne | Update | PEM | Guralp noise measurement |
Here is the data from the Guralp Seismometer for the past day or so, before I fixed the VERT-1 channel. The NS and EW show what's going on in the world, and VERT is measuring essentially the noise of the box, through the ADC, in counts. |
Attachment 1: guralp_vert_shorted.jpg
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1154
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Fri Nov 21 19:47:26 2008 |
rana | Update | PEM | Guralp noise measurement |
and here's the spectra with them connected - from the coherences, it looks like it needs to be rotated by 90 deg.
I'll next rename the channels to fix this so that we get good seismic data over the weekend with the MC. |
Attachment 1: a.png
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1156
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Fri Nov 21 21:20:24 2008 |
rana | Update | PEM | Guralp noise measurement |
This is the spectra and time series of the Guralp channels along with the Ranger (MC2). Looks like we could reduce the gain
on the ranger. The Guralp channels run into ADC noise around 40 Hz (which is OK). We'll have to look at the weekday trends
to see if they saturate. |
Attachment 1: a.png
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1165
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Mon Dec 1 15:09:27 2008 |
rob | Update | PEM | half-micron particle count is alarming |
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1167
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Tue Dec 2 19:18:10 2008 |
rana | Summary | PEM | Ranger SS-1 |
In entry http://dziban.ligo.caltech.edu:40/40m/881 and a follow up from Jenne I put in the Ranger calibration.
Since then, we've reduced the SR560 gain from 200 to 100 so the calibration factor is now:
1e-9 (m/s)/count and then 2 poles at 0 Hz, and a Q~1 zero pair at 1 Hz.
in DTT:
G = 1e-9
p = 0, 0
z = 0.7 0.7 |
1168
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Tue Dec 2 19:51:32 2008 |
rana | Update | PEM | half-micron particle count is alarming |
The 0.5 micron dust monitor count is now pretty high (36000). I wandered around the lab to see if there was anything
nasty going on but I didn't see or smell anything in particular. Since today Alberto was sitting around where the
dust monitor is while aligning the PSL beam, we should blame him. Its either garlic, cologne, or time to bathe.
The 400 day hour trend shows that while the counts are not so unusual, the 40m is dirtier than it was last year. |
Attachment 1: Untitled.png
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Attachment 2: dust.png
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