Chris,
FYI, take a look at the heliplots at=A0http://alabamaquake.com of my FBV, w=
hich is currently running without a hermetically-sealed case, along with my=
 older SG horizontal.=A0 The existing FBV case will soon be replaced by a s=
ealed case, but the current displays do show the non-hermetic condition for=
 both instruments.
=A0
Steve

--- On Wed, 11/23/11, chrisatupw@.......  wrote:


From: chrisatupw@....... 
Subject: Re: Spring for AS-1 type vertical seismometer
To: psnlist@..............
Date: Wednesday, November 23, 2011, 5:22 AM











Brett Nordgren brett3nt@.............
Subject: Re: Spring for AS-1 type vertical seismometer


Hi Dave,
    I agree, Richard has made a very nice looking instrument.

Regarding noise, I think it's the other way around.  Generally the=20
verticals are considerably less sensitive to local disturbances of=20
the ground (though much more sensitive to temperature and barometric=20
pressure changes).  Hi Brett,     Vertical Seismometers which are NOT herme=
tically enclosed may be quite noisy when compared to horizontals. They are =
strongly effected by atmospheric pressure noise and by air convection, part=
icularly if they have low mass. A Lehman type commonly has a mass of 1 to 2=
 kg. What mass does the FBV use, please?     Can you direct me to the plans=
 for the FBV, please ?     What ADC do use, please ?    I have some sheets =
of 3 thou mylar / polyester, which looks like it could be used to make a se=
ismometer bearing. Would you be interested in having a sample ?    I would =
be interested in trying to make a FBV. Can you confirm the cost of the boar=
d + postage to the UK, please ? I will need some help with the capacitors, =
the timing crystal and the ICs please. None of the UK suppliers that I can =
find have a 3 MHz crystal. The supplier which I was using has closed down. =
The pin spacings on capacitors are very variable. I think that I am
 OK for everything else. I do have a PayPal account.    I am continuing to =
=

[ Top ] 
[ Back ] 
[ Home Page ] 
Chris,
FYI, take a look at the heliplots at http://alabamaquake.com of my FBV, which is currently running w=
ithout a hermetically-sealed case, along with my older SG horizontal. =
 The existing FBV case will soon be replaced by a sealed case, but the curr=
ent displays do show the non-hermetic condition for both instruments.
 
Steve

--- On Wed, 11/23/11, chrisatupw@....... <chrisa=
tupw@.......> wrote:


From: chrisatupw@....... <chrisatupw@.......&g=
t;
Subject: Re: Spring for AS-1 type vertical seismometer
To: psnlist=
@..............
Date: Wednesday, November 23, 2011, 5:22 AM










<=
TT>
Brett Nordgren brett3nt@.............
Subject: Re: Spring for=
 AS-1 type vertical seismometer


Hi Dave,
    I agree, Richard has made a very nice looking instrument.

Regarding noise, I think it's the other way around.  Generally the=20
verticals are considerably less sensitive to local disturbances of=20
the ground (though much more sensitive to temperature and barometric=20
pressure changes).  
Hi Brett, 
<=
FONT size=3D3>    Vertical Seismometers which are NOT hermetically enclo=
sed may be 
quite noisy when compared to horizontals. They are strongly effected =
by atmospheric pressure noise and=
 by air convection, particularly if 
they have low ma=
ss. A Lehman type commonly has a mass of 1 t=
o 2 kg. 
=
What mass does the FBV use, please?
 
    Can=
 you direct me to the plans for the FBV, please ? 
    What ADC do use, please ?
    I have s=
ome sheets of 3 thou mylar / polyester, which looks like 
=
it could be used to make a seismometer bearing. Would you be 
interested in hav=
ing a sample ?
    I would be interested in trying =
to make a FBV. Can you confirm 
the cost of the board + postage to the UK, please ? =
I will need some 
help with the
 capacitors, the timing crystal and the ICs please. 
None of the UK suppliers that I can find have a 3 MHz crystal. The <=
/TT>
supplie=
r which I was using has closed down. The pin spacings on 
capacitors are very variable. I think that I am OK for everything 
else. I do have a PayPal account. <=
/PRE>
   I am continuing to=
 recover medically, but progress is very slow.
    Regards,
<=
FONT size=3D3>    Chris Chapman 
=