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. 
       See http://pages.prodigy.net/fxc/seiscoverslg.jpg 

       Regards,

       Chris Chapman   
In a me=
ssage dated 2007/06/21, tchannel@.............. writes:



At night everything fall down t=
o nothing, nice flat lines, but as soon as the sun come up I get the noise.<=
/FONT>=


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 n=
oise due to air movement. What sorts of seismometer cases are you using? The=
 recommended  is 2" Celotex glued airtight with polyurethene foam grout=
ing. This thick board has a polystyrene core covered by glass scrim and Al f=
oil. You can add double layer mylar windows. You buy clear copy film for use=
 with laser printers. 

       See http://pages.prodigy.net/fxc/seisco=
verslg.jpg 



       Regards,



       Chris Chapman