Hi George,  This is interesting.  Where can I find articles to read more 
about the basic principle. etc.   Thanks, Ted
----- Original Message ----- 
From: "George Bush" 
To: 
Sent: Wednesday, April 04, 2007 11:01 AM
Subject: Tiltmeter progress


> Chris-
>
> I wanted to report on my recent activity with the tiltmeter (NOT the
> tiltometer!).
>
> Your last comment to me about the Linear LTC1043 circuit going unstable if
> the Cx is smaller than the Cref has opened a door and I am now proceeding.
> Knowing that the circuit was working was of great value and I stopped
> trouble-shooting and have attached the circuit to the tiltmeter yesterday!
> The instrument is amazingly stable, no apparent noise on the scope, no
> sensitivity to moving my hands near the un-shielded Hg pots and it seems 
> to
> just simply work.
>
> I did a simple sensitivy check. The plate the two pots are mounted on is
> supported by screws in a triangle configuration (see
> http://ntweb.mcn.org/gbush/Tiltmeter/Construction/Construction.html).
> The pots are separated by 24" center-to-center, and the micrometer 
> leveller
> leg is separated from the other end two suppoort screws by 27 1/2". When I
> adjusted the micrometer by .01" vertically, I got an output voltage change
> reading of 0.193v. If my trig is correct this is the voltage change for a
> tilt change of 6.347 -07 deg. I have no feeling if this is getting into 
> the
> ball-park of sensitivity needed to detect Earth tides. What sensitivity do
> you think is needed?
>
> Since yesterday afternoon I have periodically recorded output voltage and
> time. This is the signal so far:
>
> Date Time Vout
> ---- ---- ----
> 3-4-07 1:21p 1.625
> 3:45p 1.594
> 5:27p 1.605
> 6:30p 1.615
> 4-4-07 9:29a 1.654
>
> Presently I am connecting the instrument to my Windaq DI-194 to try to 
> plot
> daily signal variations. Then I will be able to see if I need to add
> another stage of gain. After that, a complete mechanical tear-down to
> shield the Hg cups and connecting tube and to build an insulated enclosure
> with a heater in the top.
>
> I can see light at the end of the tunnel and am really geting excited!
>
>
> George
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
> 

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)