I have my shake in the closet of my house, which sits on a large concrete pad. The RS also sits on this same 4000 sq foot floor (concrete pad). Would I see any differences in the sensitivity of the RS if I placed a standard sized brick on top of the RS, to ensure better physical connectivity with the concrete slab?
Would sensitivity be increased, or would there be damping or no change? Just curious.
Hello Gary,
it is indeed a very interesting question! The placement on a concrete pad is already one of the best for our Shake, ensuring good quality data, keeping in mind that there is no strict need of an anchor: https://manual.raspberryshake.org/commonlyAskedQuestions.html#anchoring-how-do-i-anchor-my-raspberry-shake-to-the-floor
To answer your question, there shouldn’t be any negative effects for your RS4D of putting a standard brick weight on top of it, other users have done something similar for their seismic vaults (like here: https://manual.raspberryshake.org/_downloads/Kinabalu-downloadedSept252018.pdf).
However, regarding the eventual positive effects, going by theory, the sensors work at their best when they don’t have any other movement than the one produced by the shaking of the Earth, as you can easily imagine, because everything else would be only unwanted noise (in the case of wanting to measure earthquakes).
So, adding a weight, or anchoring it to the ground, would pose a possible advantage, especially with stronger motions. On this, we encourage you to experiment in the coming days/weeks/months, and if you want, keep us posted with your results!
To close, a great example of a Shake anchor, realised by Steve Caron for his instrumentation: https://raspberryshake.org/diy-guide-for-a-home-raspberry-shake-vault/
Gary
The best thing is to anchor it to the slab as Stormchaser said, if you can’t, the solution you propose works.
Regarding damping, this does not change. It adds damping in the case that you put it on carpets or wooden floors
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Just a brief report…After adding the additional weight of a 1/2 brick on top, it did not change the response of the RS4D at all.
Thanks for following up. I have been curious about this outcome. I just tonight put a weight on my RB and it seems to help reduce noise from household movement. Time will tell if that helps or hinders EQ detection. This article suggests there is an increase in SNR as long as the mass is not too big.
Regards,
Bob
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Interesting to see that you say " it seems to help reduce noise from household movement" but you did not say what type of floor or substrate you are referring to, or whether on the ground floor or above. In my case, it was a solidly coupled concrete floor ( approx 4000 square ft, with marble tile) coupled at ground level.
Hello Harv,
Thanks for the info. I read your response on the RS network page. I also read your lengthy read on the QRZ page. I am impressed. You have had a long and interesting ham life as K2PI. A very intersesting read. I am WA6SUL since I was age 18, in the early 1970’s, and
I was in the Phillipines (Cebu City, Mactan Island) as an USAF sergeant in 1968, but was not able to take any ham radio gear with me because it was so heavy and bulky in those years (think 10 Meter AM Gonset transceiver). But, I found your QRZ info to be interesting. It sounds like you have alot of acreage (compared to me now ) to install antennas for ham radio. I miss those old days when you could string up a 180 meter antenna, with no comments from neighbors about it. Now, I am 76 years old, and too old to try to keep up with the expensive hobby of amateiur radio. I still try to keep up with what is available to me via my smaller antennas, via SDR monitoring.
Anyway, an interesting post on your QRZ page. I wish you continued progress in your amateur radio interests.
p.s. I am R29F6 on the Raspberry Shake list, in Newport Beach, CA area. I also stream the YouTube seismometer streams, https://www.youtube.com/channel/UCyWplVN2kB_-ovNqSNUpPkg and https://www.youtube.com/channel/UCZllE0Jqlp1MeJIrkn9EpMw.
73,
Gary
Hi Gary: My S&B is in a walkout basement, partially at ground level to the north, and at about 10 feet underground to the south. The addition of a weight seems to have dampened what may be micro-oscillations that happen as a result of the roughness of the concrete foundation slab it sits on. With the weight, my overall velocity seems lower on average, and at night when we are all sleeping, even more based on what I am seeing. I wonder if anyone has developed a characterization protocol for noise for Shake velocity counts? I would enjoy using that to compare before and after in a more empirical manner.
Thanks,
Bob
Hi Gary:
Thanks for checking out my QRZ page, and thanks for your service in the USAF. I was also in the Philippines (Subic Bay) as a young Marine Corporal in 1982, and went back years later to serve at the Embassy in Manila as a Communications Officer. I met my wife on a visit to Cebu City in 1990, and I’ve visited the Philippines frequently since.
I enjoy Amateur Radio and other technical hobbies. I have a few acres, and it’s enough to set up what I want and without the encumbrances of an HOA, I am unmolested while doing so. I also recently set up a GOES-16 receive station using a small grid-dish and SDR, which has been enjoyable. An image that just came in this morning is attached.
The Youtube streams are very interesting. I will bookmark that to watch since I am sure there is a lot of activity.
73!
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