VSE-355G3 Cart Test Results :
this page presents data and summarises conclusions from the suite of
tests done at Caltech SeismoLab in 2002/2003. The test consists of
placing the VSE-355G3 on a cart alongside an Episensor, hooked up to a
Quanterra 24-bit datalogger also on the cart.
We move the cart along the hallway ~18m in about 11s, backwards and
forwards.
This helps establish whether the VSE is capable of recording on-scale
and with clarity to the specifications claimed by the
manufacturer. (ie. 2m/s full scale velocity)
VSE-355G3 Test Results - 16 September 2003
Bad results from March Tests prompted overhaul of instrument in Japan,
correspondence indicates cross-sensitivity and inadequate clip level
of Vertical sensor is fixed (elevator tests confirm the clip level -
elevator speed = 1m/s). Mr. Wada overhauled instrument on 15Sept for
whole day - replaced entire suspension of all three components.
Tested using Quanterra Q680, recently returned from Quanterra for repairs.
NOTE: EPISENSOR Vertical channel was faulty for whole of the data gathering.
Test involves rotating instrument in 45degree rotations, to see how
cross coupling affected by this.
Description of Tests
Links to Files and Plots for each 'test' (ie. each traverse up or down the hall)
SERIES 1 : Morning : VSE on HL?
Test 1
Test 2
Test 3
NOTE: VSE rotated 45degrees ANTICLOCKwise at this stage - see README files for Details
Test 4 - VSE 45degrees to EPI - no obvious cross coupling
Test 5
NOTE: VSE rotated 45degrees ANTICLOCKwise at this stage - see README files for Details
Test 6 - VSE clips at 240cm/s w/o mean removed (pre-event not zero)
Test 7 - VSE out-of-plane same as EPI in-plane!)
Test 8 - VSE out-of-plane same as EPI in-plane!)
SERIES 2 : Lunch : Calibration test followed by more cart tests, as Mr. Yokoi was not satisfied with observed divergence in out-of-plane motions. VSE on HH? (switched!)
Test 1 - VSE in-plane almost zero!
Test 2 - as above
SERIES 3 : Early Afternoon : Calibration test involved changing and modifying pins. This may have caused connection loss to VSE channel. Connections checked. VSE on HHE
Test 1 - same problem as in Series 2
Test 2 - as above
SERIES 4 : Late Afternoon : Rechecked connections, switched VSE to HL?
Test 1 - problem seems solved!
Test 2 - VSE just clips at 240cm/s w/o mean removed
NOTE: VSE rotated 90degrees ANTICLOCKwise at this stage - see README files for Details
Test 3 - VSE clips at 240cm/s again w/o mean removed - but pre-test position is at -170cm/s!!!!
Test 4
plot of all data for Series4 illustrates how CSE does not return to zero after certain tests [.ps version]
Data from Tokyo-Sokushin
12 May 2003 The Vertical cross-talk has been fixed after modifications to its suspension
X-axis result
Y-axis result
2 May 2003 as 29 April 2003, all 3 comps
X-axis result - cross-talk in Z-axis
Y-axis result - no cross-talk in Z-axis
29 April 2003
X-axis result - cross-talk in Z-axis
Y-axis result - no cross-talk in Z-axis
VSE-355G3 Test Results - 26 March 2003
Bad results from 11 March Tests. Possible problems may result from 3rd
instrument hooked up to DSN at same time - though likely this
instrument and datalogger (located in S. Mudd sub-basement) recorded
as DSN3.
Test involves rotating instrument in 45degree rotations, to see how
cross coupling affected by this.
Description of Tests
Links to Files and Plots for each 'test' (ie. each traverse up or down the hall)
VSE HHE in direction of motion
Test 1 - VSE out-of-plane same as EPI in-plane!
Test 2 - VSE out-of-plane same as EPI in-plane!
Test 3 - VSE out-of-plane same as EPI in-plane!)
NOTE: VSE rotated 45degrees CLOCKwise at this stage - see README files for Details
VSE HHN 45 degrees to direction of motion
Test 4 - strange - not like 45degrees at all!
Test 5 - more like 45degrees - E and N VSE similar shape
NOTE: VSE rotated 45degrees ANTI-clockwise at this stage - see README files for Details
VSE HHE in direction of motion [as Tests 1-3]
Test 6 - as test 1
Test 7 - as test 1 - VSE out-of-plane clips!
Test 8 - as test 1
NOTE: VSE rotated 90degrees ANTI-clockwise at this stage - see README files for Details
VSE HHN in direction of motion
Test 9 - VSE vert couples with in-plane motions!
Test 10 - as above
Test 11 - as above
NOTE: VSE rotated 45degrees ANTI-clockwise at this stage - see README files for Details
VSE HHE 45 degrees to direction of motion
Test 12 - as expected for 45degrees - VSE E and N similar, ~1/root2 of EPI in-plane
Test 13 - as expected for 45degrees - VSE E and N similar, ~1/root2 of EPI in-plane
Conclusions:
1. VSE V channel clipping not observed in this test, never went above 30cm/s
2. strong coupling is not observed in all orientations:
a - when HHE of VSE is in direction of motion : couples with HHN out-of-plane [tests ?, ?]
b - when HHN of VSE is in direction of motion : couples with Vertical channel [tests ?, ?]
3. though HHE, HHN reach 200cm/s at power surge, they struggle to measure over 150cm/s during tests. Even when EPI is clearly measuring over 200cm/s in the direction of motion.
VSE-355G3 Test Results - 11 March 2003
Mr. Isamu Yokoi returned to Caltech. After discussing whether the
observed cross-coupling of the in-plane motions to both the
out-of-plane horizontal, and the vertical axes, we performed another
suite of tests. In this case, we took data after rotating the VSE
90degrees 4 times.
Description of Tests
We first noticed a low clip of the VSE Vertical Direction upon powering-up the instrument:
plot of velocity spikes at powering-up - Vert comp clips at 32cm/s [this is Test 1]
eps version of above plot
Links to Files and Plots for each 'test' (ie. each traverse up or down the hall)
VSE HHE in direction of motion
Test 2 - in-plane/out-of-plane VSE same size/shape! (1/2 EPI in)
Test 3 - in/out VSE same size/shape! (1/2 EPI in)
Test 4 - in/out VSE same size/shape! (1/2 EPI in)
Test 5 - in/out VSE same size/shape! (1/2 EPI in)
NOTE: VSE rotated 90degrees anti-clockwise at this stage - see README files for Details
VSE HHN in direction of motion
Test 6 - in-plane/V channel VSE same shape
Test 7 - in/V channel VSE same shape
Test 8 - in/V channel VSE same shape, V clip at ~30cm/s
Test 9 - in/V channel VSE same shape
NOTE: VSE rotated 90degrees anti-clockwise at this stage - see README files for Details
VSE HHE in direction of motion
Test 10 - in/out VSE same size/shape! (1/2 EPI in)
Test 11 - in/out VSE same size/shape! (1/2 EPI in)
NOTE: VSE rotated 90degrees anti-clockwise at this stage - see README files for Details
VSE HHN in direction of motion
Test 12 - in/V channel VSE same shape [in(VSE) ~1/3 in(Epi), Z(VSE) clips)]
Test 13 - in/V channel VSE same shape
Sample SAC files:
All files, uncorrected for gain etc.
Test 2 files
Test 6 files
Test 10 files
Test 13 files
Conclusions:
1. VSE V channel clips at about 30cm/s, not 200cm/s
2. strong coupling observed in all test orientations:
a - when HHE of VSE is in direction of motion : couples with HHN out-of-plane [tests 2-5, 10-11]
b - when HHN of VSE is in direction of motion : couples with Vertical channel [tests 6-9, 12-13]
3. though HHE, HHN reach 200cm/s at power surge, they struggle to measure over 100cm/s during tests. Even when EPI is clearly measuring over 200cm/s in the direction of motion.
VSE-355G3 Test Results - 27 Nov 2002
we did some more tests to see if we could identify the problem of
out-of plane components coupling with in-plane motion.
Description of Tests
Links to Files and Plots for each 'test'
test 1 had gaps in MiniSEED file
Test 2
Test 3
NOTE: VSE rotated 90degrees at this stage - see README files for Details
test 4 had gaps in MiniSEED file
Test 5 - VSE clips
Test 6
Test 7
data from the above files is in the following SAC files:
Tar files for all Tests VEL - SAC format
Tar files for all Tests ACCN - SAC format
Tar files for all Tests DISP - SAC format
VSE-355G3 Test Results - 12 Nov 2002
Description of Tests
Links to Files and Plots for each 'test'
Test 1
Test 2
Test 3
Test 5
Test 6
John Clinton
Last modified: Tue Oct 7 13:23:17 PDT 2003