CMG-40T (60 sec) Broadband Seismometer



  The Guralp CMG-40T-60s is a three-component broadband seismometer ideally suited for installation in vaults with moderate noise.

 







  Features

 

  • True broadband force-feedback instrument
  • Direct velocity outputs
  • Self-contained in a waterproof steel case
  • Fully adjustable levelling feet
  • No mass clamping required    plug in and go
  • High sensitivity and dynamic range

    Inside the 40T

  • The 40T can be supplied with response options of 10 s    100 Hz, 30 s    100 Hz and 60 s    100 Hz.
  • Its high-gain feedback loop eliminates mechanical non-linearity (the overall measured linearity exceeds 90 dB) and minimizes resonances in the spring system.
  • Low-frequency vibration modes are carefully avoided in the design. The lowest spurious vibration mode of the 40T is a barely measurable resonance at 440 Hz.
  • Single-component vertical and horizontal sensors (CMG-40V and CMG-40H) are also available.

 

  Specifications
Velocity output bandwidth 10 s    100 Hz or 30 s - 100 Hz
Velocity output sensitivity 2 x 1000 V/m/s,
2 x 800 V/m/s or
2 x 400 V/m/s
Peak output ±10 V (20 V peak-to-peak)
Optional high gain sensitivity 2 x 10000 V/m/s (adjustable)
Lowest spurious resonance 450 Hz
Linearity >  90 dB
Cross-axis rejection >  65 dB
Electronics noise level 172 dB (rel. lmVHz')
Operating temperature 10 to + 75 °C
Temperature sensitivity < 0.6 V per 10 °C
Mass recentring range ±3° from horizontal
Materials Stainless steel case
Gold plated contacts
0-ring seals throughout
Case diameter 154 mm
Case height (with handle) 207 mm
Weight 2.49 kg
Power supply 10 - 36 V DC
Optional low power sensor 5 V DC supply (output ±4.5 V)
Current at 12 V DC 38 mA
Calibration controls Common signal & enable lines exposed on sensor connector
Offset zeroing Adjustable through case
Optional remote control Offset zeroing with DC motors
Optional accessories Handheld Control Unit