Hi Chris,   Yes it would seem so.....and I have seen just that =
phenomenon, before and after enclosing my first sensor.  The enclosure =
made a big different.   However This occurs mostly on my enclosed =
verticals, a little bit on the Horz.  All three operate in the same =
room.  All three are fully enclosed.
  The room does not vary in temp. much at all.  It is a basement living =
area and stays about 68 day and night. The room might vary 5 degrees.  I =
have even put a heater in the room to raise the temp. with no affect on =
the noise. Also a fan in the room, with no increase in noise. The noise =
is timed perfectly with the rising and setting of the sun,  it starts =
with the sun rise, 7:00am, and ends at 4:00pm.  =20

Most days, it is noticeable, but not problematic.   Today it was quiet a =
mess.  Today's temp was 94, and a weather front moving thru.    Tomorrow =
will be hot, but with a high pressure area.     I will see if the =
pattern changes.
The temp should change in a few days, so I will see if it is temperature =
related.

Thanks, Ted


  ----- Original Message -----=20
  From: ChrisAtUpw@..........
  To: psn-l@.................
  Sent: Wednesday, June 20, 2007 7:22 PM
  Subject: Re: Weather Noise


  In a message dated 2007/06/21, tchannel@.............. writes:


    At night everything fall down to nothing, nice flat lines, but as =
soon as the sun come up I get the noise.
    Most days its not too bad.  I notice it more on a vertical sensor =
than a horz sensor.


  Hi Ted,

         This sounds much more like convection noise due to air =
movement. What sorts of seismometer cases are you using? The recommended =
 is 2" Celotex glued airtight with polyurethene foam grouting. This =
thick board has a polystyrene core covered by glass scrim and Al foil. =
You can add double layer mylar windows. You buy clear copy film for use =
with laser printers.=20
         See http://pages.prodigy.net/fxc/seiscoverslg.jpg=20

         Regards,








Hi Chris,   Yes it would seem =
so.....and=20
I have seen just that phenomenon, before and after enclosing my first=20
sensor.  The enclosure made a big different.   However =
This=20
occurs mostly on my enclosed verticals, a little bit on the=20
Horz.  All three operate in the same room.  All three are =
fully=20
enclosed.
  The room does not vary in temp. =
much at=20
all.  It is a basement living area and stays about 68 day and=20
night. The room might vary 5 degrees.  I have even put a =
heater=20
in the room to raise the temp. with no affect on the noise. Also a fan =
in the=20
room, with no increase in noise. The noise is timed perfectly with =
the=20
rising and setting of the sun,  it starts with the sun rise, =
7:00am, and=20
ends at 4:00pm.   
 
Most days, it is noticeable, but not=20
problematic.   Today it was quiet a mess.  Today's temp =
was 94,=20
and a weather front moving thru.    Tomorrow =
will be=20
hot, but with a high pressure area.     I will see =
if the=20
pattern changes.
The temp should change in a few days, =
so I will see=20
if it is temperature related.
 
Thanks, Ted
 
 

  
----- Original Message ----- 
  From:=20
  ChrisAtUpw@....... 
  
To: psn-l@.............. 
  
Sent: Wednesday, June 20, 2007 =
7:22=20
  PM
  
Subject: Re: Weather =
Noise
  

In a=20
  message dated 2007/06/21, tchannel@..............=20
  writes:


  At night everything fall down to nothing, nice flat =
lines, but=20
    as soon as the sun come up I get the noise.
Most days its =
not too=20
    bad.  I notice it more on a vertical sensor than a horz=20
    sensor.

Hi=20
  Ted,

       This sounds much more =
like=20
  convection noise due to air movement. What sorts of seismometer cases =
are you=20
  using? The recommended  is 2" Celotex glued airtight with =
polyurethene=20
  foam grouting. This thick board has a polystyrene core covered by =
glass scrim=20
  and Al foil. You can add double layer mylar windows. You buy clear =
copy film=20
  for use with laser printers. 
       =
See=20
  http://pages.prodigy.net/fxc/seiscoverslg.jpg=20
  

      =20
  Regards,

       Chris =
Chapman=20