PSN-L Email List Message

Subject: Re: New Lehman seismometer pivots 2
From: "Robert O. Green" rog@..........
Date: Sat, 02 May 2009 06:24:36 -0700


Hi  Jon,

Thank you for these pictures they help.

Is the top pivot a set of crossed carbide steel shafts?

Is the bottom pivot a SS ball bearing on the boom against a SS bolt head?

I am about to begin my effort.  It seems the pivots are everything.

Rob

Jón Frímann wrote:
> Hi
>
> Here are pictures of the top and lower pivots. The top is a hindge that
> allows free movement of the arm.
>
> It was recomenned to me that I should put the magnet on the base, not
> the arm. But I am not sure about the diffrance, I don't think it is
> none. But it works anyway.
>
> I am still unable to get the sensor frequancy below 0.4Hz. But this
> design is a lot more flexable then the last one I used.
>
> After the weekend I am going to do one more change. I plan to change the
> setting of the arm. So it has not such sharp angle, but I belive that is
> hampering my effort in getting the frequancy below 0.4Hz, as sharp angle
> means faster movement of the arm.
>
> http://www.jonfr.com/myndir/v/geology/lehman/p5010001.jpg.html
> http://www.jonfr.com/myndir/v/geology/lehman/p5010002.jpg.html
> http://www.jonfr.com/myndir/v/geology/lehman/p5010003.jpg.html
>
> Regards.
> Jón Frímann.
>
>
>
> On fim, 2009-04-30 at 19:46 -0700, Robert O. Green wrote:
>   
>> Jon,
>>
>> Very nice.
>>
>> Can you describe the upper and lower pivots?
>>
>> Is there advantage to having the coil on the boom rather than the magnet?
>>
>> Rob
>>
>> Jón Frímann wrote:
>>     
>>> Hi all
>>>
>>> I got a new lehman seismomter build from the old one, that was not
>>> working. The new one is bit more complex and more adjustable. Now I just
>>> have to figure out how to get the seconds down to 10 to 20 seconds.
>>>
>>> Here are pictures.
>>>
>>> http://www.jonfr.com/myndir/v/geology/lehman/p4300001.jpg.html
>>> http://www.jonfr.com/myndir/v/geology/lehman/p4300002.jpg.html
>>>
>>> Regards.
>>>
>>> ------------------------------------------------------------------------
>>>
>>>
>>> Internal Virus Database is out of date.
>>> Checked by AVG - http://www.avg.com
>>> Version: 8.0.176 / Virus Database: 270.12.3/2075 - Release Date: 4/22/2009 5:25 PM
>>>
>>>
>>>       
>> __________________________________________________________
>>
>> Public Seismic Network Mailing List (PSN-L)
>>
>> To leave this list email PSN-L-REQUEST@.............. with
>> the body of the message (first line only): unsubscribe
>> See http://www.seismicnet.com/maillist.html for more information.
>>     
>> ------------------------------------------------------------------------
>>
>>
>> Internal Virus Database is out of date.
>> Checked by AVG - http://www.avg.com
>> Version: 8.0.176 / Virus Database: 270.12.3/2075 - Release Date: 4/22/2009 5:25 PM
>>
>>     

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)


[ Top ] [ Back ] [ Home Page ]