Seismographs in Schools
Overview
I updated the set up of the seismograph at Linux Pauling Middle School. You can learn more about it at the IRIS web site mentioned below.
The hardware is an AS-1. http://www.jclahr.com/science/psn/as1/index.html The version they have does not use a cup of oil as a damper! Too messy and requires maintenance. It uses magnets.
I worked on this a bit in October 2012. Then put it aside. Picked it up again today Jan 31 2013. It's done Feb 5
IRIS
IRIS is where the data from this seismograph is sent.
IRIS = Incorporated Research Institutions for Seismology
Details about the one at Linus Pauling Middle School LPOR
Software
Original software, AmaSeis
Documentation: http://web.ics.purdue.edu/~braile/edumod/as1lessons/UsingAmaSeis/UsingAmaSeis.htm
http://harvey.binghamton.edu/~ajones/AmaSeis.html
Alan Jones did the original software. I contacted him via email and got some information. See the hardware section below.
New software, jAmaSeis
Information page: http://www.iris.edu/hq/programs/education_and_outreach/software/jamaseis
There is a beta available but I can't give you the secret login here. http://www.iris.edu/hq/jamaseis/
Hardware
The computer is a Zotac Z-Box running Windows 7. It has 8 GB of RAM (about 8 times more than it needs) and an 80 GB 2.5" hard drive.
The AS-1 is connected through a USB to serial adapter.
AS-1
Calibration
The easiest way is to follow the instructions in the front of the Amaseis manual.
There's a knob on the black box to adjust the gain of the seismo amplifier. Start the program, bring up the setting page and set gain = 25. Put it in helicorder mode. Turn the knob until the line showing output shows up in the middle of the screen. That's it. Quit and start the jAmaseis program to do actual data collection.
Writing your own software if so inclined
"As far as the code to receive the data from the AS-1, it is very simple: 2400 baud, 8-bits, 1 stop bit ASCII
Each data point is an ASCII number between 0 and 4096. (I subtract 2048 to get +/- data.)
The data comes in as, e.g.
2567<cr><lf> 2984<cr><lf> ...
So, all you have to do is read those ASCII digits and convert to binary and subtract 2048.
I figure out the sample rate on-the-fly by seeing how many samples come in in a minute. I adjust after each hour of data.
You have to do the above because the black box is not crystal controlled (I am told) so the data rate varies from box to box.
Is that enough to get you started?"
Yes -- The first time I tried the setup out I used "putty" to connect directly to the com port and watch the data coming in to confirm the hardware worked.
