PSN-L Email List Message

Subject: Re: sensor in a well
From: Andrew Little little.aa@.........
Date: Sun, 7 Nov 2010 23:50:51 +0100


Thanks Geoff,
There is an iron ladder down to the water's surface 10m. The house was built
in 1923 and we are not keen climb down. I suppose I need to monitor the
typical fluctuation in water level. Perhaps one of these laser measures as
used for room dimensions would work, aimed at a suitable float. Once the
seasonal variation is determined then a suitable sensor would have to
operate over that range. If the movement is slight then a coil/magnet float
might do the trick. If we are talking 50cm I think I need another solution.
Perhaps optical?
Andy


On 7 November 2010 22:59, Geoffrey  wrote:

> Possibly float a magnet on the surface
> held in place by whatever and then
> have a coil on the wall of the well ?
>
> or, vice versa.
>
> getting the stuff into place is a big wonder.
>
> I often thought a big water tower might make a good
> vertical sensor if you hydraulically amplify
> the pressure changes related to ground motion.
> The water is a fluid and non-compressible
> with lots of mass and momentum, every tiny undulation should
> cause considerable pressure change.
>
> Sort of like a little pressure on the break pedal causes
> big pressure in the hydraulic cylinders.
>
> When I look at the water tower at Falcon Field
> at Mesa AZ, I often think of it as a potential seismometer.
>
> But such a thing must be dedicated only to sensing.
>
> Maybe a denser fluid like mercury ?
>
> A barometer like device that reacts to motion
> instead of air pressure.
>
> geoff
>
>
> -----Original Message----- From: Ted Channel
> Sent: Friday, November 05, 2010 6:02 PM
> To: psnlist@..............
> Subject: Re: sensor in a well
>
>
>
> Hi Andy,  Is it possible to email me a pdf or copy of the article....or a
> .jpg......very interesting.
> Ted
>
> ----- Original Message ----- From: Andrew Little
> To: psnlist@..............
> Sent: Friday, November 05, 2010 11:28 AM
> Subject: sensor in a well
>
> Hi PSN list,
> I have a copy of The Amateur Scientist by C.L. Strong 1960. It is a
> collection of projects and articles from The Scientific American. In the
> Earth Science section are several articles on seismology. It was this book
> that first got me interested in the subject. One article by Elmer Rexin
> describes using a float in a well to detect seismic events.
> I happen to have a well under my house, it is cut into the limestone, the
> water surface is 10 Metres below the floor of the cellar. I know of one
> sink-hole on the plateau above the village so It is possible that the well
> could be connected to an aquifer in the limestone hillside. The well in the
> article did have a connection to lake Michigan and so acted as part of a
> giant "U-tube".
> Anyway, the point of all this is to ask if anyone thinks there could be an
> advantage in setting up some form of sensor in the well, and if so, have you
> any ideas?
> Regards,
> Andy
>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSNLIST)
>
> To leave this list email PSNLIST-REQUEST@.............. with the body of
> the message (first line only): unsubscribe
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>
Thanks Geoff,
There is an iron ladder down to the water's surface 10= m. The house was built in 1923 and we are not keen climb down. I suppose I = need to monitor the typical fluctuation in water level. Perhaps one of thes= e laser measures as used for room dimensions would work, aimed at a suitabl= e float. Once the seasonal variation is determined then a suitable sensor w= ould have to operate over that range. If the movement is slight then a coil= /magnet float might do the trick. If we are talking 50cm I think I need ano= ther solution. Perhaps optical?
Andy


On 7 November 2010 22:59, Geoffr= ey <gmvoeth@hot= mail.com> wrote:
Possibly float a magnet on the surface
held in place by whatever and then
have a coil on the wall of the well ?

or, vice versa.

getting the stuff into place is a big wonder.

I often thought a big water tower might make a good
vertical sensor if you hydraulically amplify
the pressure changes related to ground motion.
The water is a fluid and non-compressible
with lots of mass and momentum, every tiny undulation should
cause considerable pressure change.

Sort of like a little pressure on the break pedal causes
big pressure in the hydraulic cylinders.

When I look at the water tower at Falcon Field
at Mesa AZ, I often think of it as a potential seismometer.

But such a thing must be dedicated only to sensing.

Maybe a denser fluid like mercury ?

A barometer like device that reacts to motion
instead of air pressure.

geoff


-----Original Message----- From: Ted Channel
Sent: Friday, November 05, 2010 6:02 PM
To: psnlist@web= tronics.com
Subject: Re: sensor in a well



Hi Andy, =A0Is it possible to email me a pdf or copy of the article....or a= .jpg......very interesting.
Ted

----- Original Message ----- From: Andrew Little
To: psnlist@web= tronics.com
Sent: Friday, November 05, 2010 11:28 AM
Subject: sensor in a well

Hi PSN list,
I have a copy of The Amateur Scientist by C.L. Strong 1960. It is a collect= ion of projects and articles from The Scientific American. In the Earth Sci= ence section are several articles on seismology. It was this book that firs= t got me interested in the subject. One article by Elmer Rexin describes us= ing a float in a well to detect seismic events.
I happen to have a well under my house, it is cut into the limestone, the w= ater surface is 10 Metres below the floor of the cellar. I know of one sink= -hole on the plateau above the village so It is possible that the well coul= d be connected to an aquifer in the limestone hillside. The well in the art= icle did have a connection to lake Michigan and so acted as part of a giant= "U-tube".
Anyway, the point of all this is to ask if anyone thinks there could be an = advantage in setting up some form of sensor in the well, and if so, have yo= u any ideas?
Regards,
Andy



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Public Seismic Network Mailing List (PSNLIST)

To leave this list email PSNLIST-REQUEST@.............. with the body of the m= essage (first line only): unsubscribe
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