In a message dated 25/12/2008, cjburch@........... writes:

S-T Morrissey's  website has an abstract for the fall 2000 AGU meeting 
regarding a "Very  Broadband Beam-Balance Tiltmeter."  It also has captions for a 
poster  presentation on the same topic at the 2001 spring SSA meeting.  But no  
photos, drawings or diagrams seem to be available.  
Hi Chuck,
 
    Since the posters were displayed at the meetings,  the preliminary 
information is in the public domain. Accessing it may be a  different matter. Sean 
was going to patent the device, but I am uncertain as to  what actually 
happened, particularly with the long delays in processing  American Patents. I did 
try to follow up the poster and eventually managed to  get a reference SSA / AGU 
number. It is listed as C23 on 
_http://www.seismosoc.org/meetings/ssa2001.html_ (http://www.seismosoc.org/meetings/ssa2001.html) 
 
    Sean presented a 30 page A4  poster with Brian J Mitchell of St Louis 
University. He is now an Emeritus  Professor _mitchbj@............ 
(mailto:mitchbj@............  in the  Department of Earth and Atmospheric Sciences. A 70 
page final NSF report was  produced. I suggest that you ask him and the NSF? 
 
    It was funded by the NSF in October 1999, so there  must be records of 
this and of the report. The work was completed in October  2000. The NSF grant 
reference is 9905328. The project funding was for  $120,000.
See _http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=9905328_ 
(http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=9905328) 

Does anyone  know if the abstract and poster captions are all that is 
available?  I'd  like to build such a device and any Morrissey diagrams or photos 
would help me  from reinventing the wheel (probably several times).  He mentions 
"a new  low torque hinge flexure" and "a unique vertical mass centering 
adjustment,"  both of which sound interesting.


After Sean's death the prototype level equipment  was sent to the USGS 
facility at Albuquerque, NM. I did contact Bob Hutt _bhutt@......... 
(mailto:bhutt@.........  about it, but he said that  they had broken the suspension and that 
it was no longer working. Ask him  about it?
    See also 
_http://www.iris.washington.edu/stations/seisWorkshop04/abstracts/HuttAbstract.pdf_ 
(http://www.iris.washington.edu/stations/seisWorkshop04/abstracts/HuttAbstract.pdf)    This seems to me to be a very high cost project 
with limited prospects of  success. The longest period was only about 10 
seconds. An optimal design for a  long period seismometer is likely to be different 
to that of a tiltmeter. 
 
    You can get a fair indication of the main  components from the page 
headings. I do not know how he designed the suspension,  or how he adjusted the C 
of G. But I could make an educated guess of systems  that you could try out. As 
far as I am aware, there is no very long period high  sensitivity tiltmeter 
equipment available. One problem with measuring tilts is  getting rid of near 
surface environmental noise at a fixed point /  location. Long period noise due 
to the daily thermal cycle and from surface soil  movement are also likely to 
be observed / cause problems. It is fairly  easy in principle to measure 
tilts over say 1 km of open trough.   There is a 43 m H2O tiltmeter in a salt mine 
at Walferdange in Luxembourg.  There is no substitute for a nice deep hole! 
See 
_http://www.geodesy.cwu.edu/index.html?page=http%3A//www.geodesy.cwu.edu/tilt/_ 
(http://www.geodesy.cwu.edu/index.html?page=http://www.geodesy.cwu.edu/tilt/)    However, it may be possible to monitor the position sensor on some 
long period  seismometers.
 
    Basically it was a high inertia horizontal beam  with equal mass at both 
ends. It was suspended at it's C of G. There were  position sensors at both 
ends and force feedback transducers. A very long  integration period was used, 
but no gravitational feedback. This could be an  advantage, since it will not 
be sensitive to very long period / permanent  tilts, only to changes in tilt. I 
presume that Sean used the same variable  reluctance sensors that he used in 
his seismometer. The measurement limit with  an LVDT system is likely to be 
over 0.1 nm, probably over 1 nm, due to  Barkhausen magnetic domain noise.
 
    Regards,
 
    Chris Chapman





In a message dated 25/12/2008, cjburch@........... writes:
<=
FONT=20
  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000>S-T M=
orrissey's=20
  website has an abstract for the fall 2000 AGU meeting regarding a "Very=20
  Broadband Beam-Balance Tiltmeter."  It also has captions for a poster=
=20
  presentation on the same topic at the 2001 spring SSA meeting.  But n=
o=20
  photos, drawings or diagrams seem to be available.  
Hi Chuck,
 
    Since the posters were displayed at the meeting=
s,=20
the preliminary information is in the public domain. Accessing it may be a=20
different matter. Sean was going to patent the device, but I am uncertain as=
 to=20
what actually happened, particularly with the long delays in processing=
=20
American Patents. I did try to follow up the poster and eventually managed t=
o=20
get a reference SSA / AGU number. It is listed as C23 on http://www.seismosoc=
..org/meetings/ssa2001.html
 
    Sean presented a 30 page A4=20
poster with Brian J Mitchell of St Louis University. He is now an Emeri=
tus=20
Professor mitchbj@........... in=20=
the=20
Department of Earth and Atmospheric Sciences. A 70 page final NSF report was=
=20
produced. I suggest that you ask him and the NSF? 
 
    It was funded by the NSF in October 1999, so th=
ere=20
must be records of this and of the report. The work was completed in October=
=20
2000. The NSF grant reference is 9905328. The project funding was for=20
$120,000.
See h=
ttp://www.nsf.gov/awardsearch/showAward.do?AwardNumber=3D9905328
<=
FONT=20
  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000>Does=20=
anyone=20
  know if the abstract and poster captions are all that is available? =20=
I'd=20
  like to build such a device and any Morrissey diagrams or photos would hel=
p me=20
  from reinventing the wheel (probably several times).  He mentions "a=20=
new=20
  low torque hinge flexure" and "a unique vertical mass centering adjustment=
,"=20
  both of which sound interesting.


    After Sean's death the prototype level equipmen=
t=20
was sent to the USGS facility at Albuquerque, NM. I did contact Bob Hutt bhutt@........ about it, but he said=
 that=20
they had broken the suspension and that it was no longer working. Ask h=
im=20
about it?
    See also http://www.iris.washington.edu/stations/seisWorkshop04/abstra=
cts/HuttAbstract.pdf =20
This seems to me to be a very high cost project with limited prospects of=20
success. The longest period was only about 10 seconds. An optimal design for=
 a=20
long period seismometer is likely to be different to that of a tiltmeter. 
 
    You can get a fair indication of the main=20
components from the page headings. I do not know how he designed the suspens=
ion,=20
or how he adjusted the C of G. But I could make an educated guess of systems=
=20
that you could try out. As far as I am aware, there is no very long period h=
igh=20
sensitivity tiltmeter equipment available. One problem with measuring tilts=20=
is=20
getting rid of near surface environmental noise at a fixed point /=20
location. Long period noise due to the daily thermal cycle and from surface=20=
soil=20
movement are also likely to be observed / cause problems. It is fairly=20
easy in principle to measure tilts over say 1 km of open trough. =20
There is a 43 m H2O tiltmeter in a salt mine at Walferdange in Luxembou=
rg.=20
There is no substitute for a nice deep hole! See http://www.geodesy.cwu.edu/index.html?page=3Dhttp%3A//www.geode=
sy.cwu.edu/tilt/ =20
However, it may be possible to monitor the position sensor on some long peri=
od=20
seismometers.
 
    Basically it was a high inertia horizontal beam=
=20
with equal mass at both ends. It was suspended at it's C of G. There were=20
position sensors at both ends and force feedback transducers. A very long=20
integration period was used, but no gravitational feedback. This could be an=
=20
advantage, since it will not be sensitive to very long period / permane=
nt=20
tilts, only to changes in tilt. I presume that Sean used the same varia=
ble=20
reluctance sensors that he used in his seismometer. The measurement limit wi=
th=20
an LVDT system is likely to be over 0.1 nm, probably over 1 nm, due to=20
Barkhausen magnetic domain noise.
 
    Regards,
 
    Chris Chapman