PSN-L Email List Message
Subject: Re: Noise
From: Mark Robinson mark.robinson@...............
Date: Fri, 24 Nov 2006 13:25:12 +1300
> Hi Folks, A while back I asked for help in determining the source of some noise showing up on my Helicorder. This is an update to that question.
> I have excluded auto traffic, as the noise happens weather it is weekends or work days, at about the same time.
> I have excluded the schools in the area for the same reasons
> I have excluded construction for the same reason.
> I am not 100 percent sure of these exclusions, but for the most part, I think it is something else.
> I have gone back several days on the Helicorder to see if I could find patterns, and I have found that all is quiet starting about 5:00 pm local time, 00 UTC. Things remain quiet until 08:35 am, 15:35 UTC. During the hours 8:00 am to 5:00 pm the noise comes and goes sometimes lasting less than one mins and sometimes lasting 5 to 10 mins.
> The sensor, a Lehman, is in my basement. It is on a concrete floor next to a concrete wall, and the house above is wood and brick.
> Could this noise be the sun? At about the time the noise begins the sun rises above the trees and shines on the east side of our house, which is also the wall near the sensor.
> Could this warming of the wood and bricks, above the basement, and their expansion cause the noise. As the clouds block the sun during the day, might this cause the intermittent noise during the day? The noise stops about the time the sun no longer hit the house.
> I could test this theory on a overcast day and I will do so, but I just wanted to get your input.
> Thanks, Ted
Is there any heavy industry within a few miles ?
Does the noise happen on the weekends ?
Could you post am image of the helicorder showing the noise ? ?
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