PSN-L Email List Message

Subject: Re: Please review these SAC
From: Jim ODonnell geophysics.jim@.........
Date: Wed, 9 Oct 2013 22:14:29 -0700


Chris- I am keeping the sensors from getting too hot & cause the metal to
expand & Burp..
Painting them White works & is a quick way to go.  They are the new Chinese
Sunfull, PS-1, (~$1k US) which work quite well, but the 1 Hz phone is not
easy to use in the field as too sensitive to being level & easily damaged.

Not sure what actually happens inside the case!

<<<   Jim


On Wed, Oct 9, 2013 at 6:40 PM, Tiago A.  wrote:

> Thanks for the answer Jim.
>
> I suspected also that it was something to do with the geophone, but how
> does the epoxy help? Tomorrow i can check a 10km distance station to check
> if it also record something (which i dont believe).
>
> Netherless i forgot to post the link of the SAC files, they can be
> downloaded here:
> https://dl.dropboxusercontent.com/u/15802004/sac.zip
>
> Chris, in my case the geophone (1996 one) is inside a house, covered with
> styrofoam.
>
>
> 2013/10/10 
>
> From: Jim ODonnell 
>> To: psnlist 
>> Sent: Thu, 10 Oct 2013 1:00
>> Subject: Re: Please review these SAC
>>
>>
>> Tiago- I call it a seismometer Burp (hiccup is good too)- happens with
>> the 1 Hz phones, although I think all seismometers do it, but not as much.
>>  I use 1 Hz phones in the desert for field work & in the summer they did
>> this a lot, until I painted them with a white epoxy paint.
>> You need another sensor recording nearby to see if the ground actually
>> moved............    Jim
>>
>> Hi Jim,
>>
>>     Do you have any idea what is happening, please ? Maybe the top spring
>> is expanding out of step with the bottom spring and buckling ? Are the
>> geophones in direct sun light ? Are they the old type geophones or the
>> redesigned newer ones ? White epoxy paint should reduce the amount of
>> radiation absorbed, but it could also seal the unit completely. Have you
>> tried wrapping them in Al foil to reduce absorbed radiation ? How about
>> mounting them inside a Copper tube to slow down / prevent differential
>> heating ?
>>
>>    Regards,
>>
>>    Chris Chapman
>>
>>
>>
>>
>>
>> ______________________________**____________________________
>>
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>> To leave this list email PSNLIST-REQUEST@.............. with the body of
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>>
>
>
Chris- I am keeping the sensors from getting too hot = & cause the metal to expand & Burp..
Painting them White works &= amp; is=A0a quick way to go.=A0 They are the new Chinese Sunfull, PS-1, (~$= 1k US)=A0which work quite well, but the 1 Hz phone is not easy to use in th= e field as too sensitive to being level & easily damaged.

Not sure what actually happens inside the case!

<<<=A0= =A0 Jim


On Wed, Oct 9, 2013 at 6:40 PM, Tiago A. <tiagoagre@.........&= gt; wrote:
Thanks for the answer = Jim.

I suspected also that it was something to do with th= e geophone, but how does the epoxy help? Tomorrow i can check a 10km distan= ce station to check if it also record something (which i dont believe).

Netherless i forgot to post the link of the SAC files, they = can be downloaded here:
https://dl.dropboxusercontent.com/u/1580= 2004/sac.zip

Chris, in my case the geophone (1996 one) is inside a = house, covered with styrofoam.


=
2013/10/10 <chrisatupw@.......>=

From: Jim ODonnell <geophysics.jim@.........>
To: psnlist <psnlist@..............>
Sent: Thu, 10 Oct 2013 1:00
Subject: Re: Please review these SAC


Tiago- I call it a seismometer Burp (hiccup is good too)- happens with the = 1 Hz phones, although I think all seismometers do it, but not as much. =A0I= use 1 Hz phones in the desert for field work & in the summer they did = this a lot, until I painted them with a white epoxy paint.
You need another sensor recording nearby to see if the ground actually move= d............ =A0 =A0Jim

Hi Jim,

=A0 =A0 Do you have any idea what is happening, please ? Maybe the top spri= ng is expanding out of step with the bottom spring and buckling ? Are the g= eophones in direct sun light ? Are they the old type geophones or the redes= igned newer ones ? White epoxy paint should reduce the amount of radiation = absorbed, but it could also seal the unit completely. Have you tried wrappi= ng them in Al foil to reduce absorbed radiation ? How about mounting them i= nside a Copper tube to slow down / prevent differential heating ?

=A0 =A0Regards,

=A0 =A0Chris Chapman





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