IRIS AS1 School Seismometer and Visits
September and Octobrer, 2004

Cedar Rapids AS1

Sue Vogel and Traci Maxted show John Lahr the Jefferson High School Seismic Station in Cedar Rapids, Iowa.  The helicorder record is posted here:


AS1 Seismometer

The damping was improved by switching from the round dish to the smaller square dish.


Lift-test calibration of  Cedar Rapids AS1 using round dish supplied by IRIS. (SAC file)

Final calibration

Final Cedar Rapids lift-test calibration using the square dish.  The polarity was also corrected. (SAC file)

Erie, IL, Middle School Seismic Station

Eire, Illinois, Middle School teacher Karen Urick and her class look at their classroom seismic station.

Erie Calibration

Eire lift-test calibration.  The lower few cm of a soda can is being used as the oil container with 5w30 oil.  The polarity is reversed and should be changed by reversing the outer-two wires attached to the "black" box.

On 9/28 the polarity was reversed and the oil cup was lifted up to bring the washer closer to the bottom of the cup.  This increased the damping, as is shown by the calibration above. (SAC file)

Elgin, IL

Rod Allen shows John the DaVinci Academy, Elgin, Illinois, Seismic Station.  This is the newer-model AS1 with a thicker spring.  The helicorder image is posted here:

Davinci calibration

DaVinci lift-tests.  Upper:  Original calibration with mineral oil in a square, light-weight plastic, dish. (SAC file) Lower:  Calibration after replacing mineral oil with  5w30 oil.   Damping should be increased by lifting the oil dish and thus reducing the space between the washer and the bottom of the dish. (SAC file)

John Lahr and Dane Alexander at Mattawan High School, Michigan.  The helicorder image is posted here:


Using the IRIS-supplied container and 10w40 oil, the system was under-damped.  Following the suggestion of Chris Chapman that the damping would be increased if the damping washer were nearer the bottom of the dish, we raised the dish by placing it on a stack of  CD's.  This worked quite well.  This is one of the AS1 systems with a larger-diameter spring.

Final Mattawan list-test calibration.


Tyler Spence and John Lahr with the James Madison Memorial High School AS1 System, Madison, Wisconsin.


Sean Wagner and Wayne Pennington of Michigan Tech working with Houghton Middle School Principal Jim Luoma on the school's seismic station.  This system uses an EAI S102 seismometer with LabView software developed at Michigan Tech.


Houghton Middle School Earthquake Bulletin Board.


Sean Wagner and Jim Diehl with their earthquaks shake table.  For full instructions on building this table, see the link on Jim's page:


Tom Diener, Earth Science teacher at Marshall School, Duluth, Minnesota.  The AmaSeis helicorder record is posted here: 


Duluth Calibration with 5w30 oil in the square, light-weight plastic, dish. (SAC file)


Duluth Calibration with 3 CD's under the plastic, dish.  The polarity has been corrected.  We measured the weight of the small square of cardboard used for the lift test.  It is 0.0374 g.  It was lifted from a location on the boom 10 cm from the hinge. (SAC file)


John Ghist and John Lahr with the AS1 system at Platte Canyon High School, Bailey, Colorado. The AmaSeis helicorder record is posted here:


We ran three calibrations of this system.

First: Original calibration with square container, 10w30 oil.  Both base plate and boom were leveled.  This is a "fat spring" system (as compared with some of the earlier AS1 models.) (SAC file)

Second:   The same as cal1.sac except that the dish has been lifted by 4 CD's and the wires on the "black box" have been reversed to correct the polarity. (SAC file)

Third:  The coil end of the base was lifted a bit with the leveling screw so that there would be more overlap between the coil and the magnet.  An additional CD was added under the oil dish, for a total of 5.  This is the calibration shown above. (SAC file)

More AS1 Information

How to set up SnagIt to place AmaSeis Helicorder records onto the Internet.

April-June Visits