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Published bySolomon Fox Modified over 8 years ago
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Geophones for Recording EQ’s OVERVIEW Local Events Aftershock Deployments Extend Period for Regional Events Simple Checks to Assure Sensor Works
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Seismometer Responses: Ammon-SLU http://eqseis.geosc.psu.edu/~cammon/HTML/Classes/IntroQuakes/Notes/notes_framed.html
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Ground Motion Amplitudes (displacement) http://eqseis.geosc.psu.edu/~cammon/HTML/Classes/IntroQuakes/Notes/notes_framed.html
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1999 PH’D Stanford U.
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Neg FeedBack- Lippman method (1983) Lennartz (German company) 4.5 Hz to 1 Hz (1s), 0.2 Hz (5s); and 0.05 Hz (20s)
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Volcan Array uses L15 If you want an affordable array start with an affordable sensor
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Two Other Methods By inverse filtering electronically (analog) Roberts (Equivalent) Circuit Peter M. Roberts, October 1989, BSSA, Vol.79, No 4, pp.1607-1617 By Digitally Applying Transfer Fn. Deconvolve- Easiest way
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Geophone Specifications: How to read a spec. sheet for 4.5 Hz, 10 Hz, responses High pass filters with a 40 dB/decade roll off 2 pole filter Measure ground velocity- Output ~40V/m/s How to measure Resistance: Rc coil resistance Rs shunt resistance Rt total resistance
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Check polarity: Tilt test Tap test How to increase output signal: Put them in series Huddle Test: Determines if they all work the same If not, are they coupled properly?
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