## page was renamed from Physical Environment Monitoring (PEM)/Seismometers/Guralp CMG-40T
Guralp CMG-40T is a 3 axis seismometer with a flat velocity response of
800 V/(m/s) in the 0.03-50 Hz band. Doesn't need to be locked for
transport and has a bubble level and leg screws for balancing.

Outputs are differential.

Needs a solid floor and a foam box in order to have good low frequency performance.


Home page: http://www.guralp.com/products/40T/

Datasheet: [[attachment:datasheet-cmg40t.pdf]]

Manual: [[attachment:manual-cmg40t.pdf]]

Breakout box circuit diagram: 

[[Guralp Preamp|{{attachment:Guralp_breakout_box_circuit.png||width=1000}}]]

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== Noise ==
We have yet to make high quality huddle test measurements of the self-noise of the Guralps. Here is there 'noise spec' plot:

{{attachment:guralpnoise.png}}


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At the 40M, we have serial # T4157 (which we got from Rich Mittleman at MIT).<<BR>>
Info from the calibration sheet:<<BR>>
zeros = 0, 0<<BR>>
poles = (-0.02365 +/- i*0.02365), -80, -160, -180<<BR>>
Response is the same for horizontal and vertical<<BR>>
Calibration sheet: [[attachment:calsheet.pdf]]


and we have serial # XXX (which we bought in July, '08)