GeoSIG arolla - VE series - Broadband Seismometer

Designed and handmade in Switzerland, arolla broadband seismometer is the culmination of years of experience designing high precision, low noise, and reliable seismic equipment.

arolla’s versatile, compact, lightweight, and rugged design, make it an ideal choice for many applications and use cases.

From the beginning, the design goals for the arolla broadband seismometer were to make the most accurate, most reliable, easy to use/deploy, and consistent quality sensor on the market. Its triaxial design, wide temperature range, low temperature sensitivity, magnetic shielding, precision factory calibration of the sensor response, and robustness help to achieve these goals and beyond.

The introduction of arolla marks the launch of a new series of seismometers by GeoSIG, which will be complemented with further exciting products.

Typical applications include study of local, regional, and teleseismic events; national seismic networks; Earth mode observations; site surveys; and more.

• Technology

• Feedback:
• Electromagnetic force balance with capacitive transducer
• Topology:
• Orthogonal triaxial X, Y, Z
• Mass centering:
• Automatic procedure during operation can be remotely initiated
  either via control line or via serial communication interface

• Performance

• Sensitivity:
• 2x600 V/m/s ±0.5% factory trimmed
• Self Noise:
• Measured self noise below NLNM from 40sec to
  8.5Hz. Within +6dB at 120sec. See plot.
• Bandwidth:
• 120 sec (0.00833 Hz) to 50 Hz
• Cross axis:
• ≤ 1% coupling; Including misalignment from axis to case reference
• Clip level:
• 17 mm/s up to 1 Hz
• Temperature:
• No re-centering required within ±45 °C

• Power Supply

• Type:
• Isolated 9 to 36 VDC
• Consumption:
• <1 W typical at 12 VDC
• Protection:
• Over voltage, reverse voltage, ESD, complies with EMC CE

• Interface

• Connector:
• Single 24 pin IP68 hermetic
• Output X, Y, Z:
• Velocity; 40 Vpp differential
   Mass position; 10 Vpp single ended
• Calibration:
• Accept analogue test signals to be injected into the individual cells via
  dedicated calibration coils. Calibration function can be remotely
  activated and inhibited.
• Serial:
• RS485

• Physical & Environmental

• Material:
• Lightweight, rugged aluminium construction (Stainless steel housing optional)
• Diameter:
• 235 mm
• Height:
• 283 mm incl. feet & handle
• Weight:
• < 10 kg (< 9.8 liter)
• Ingress:
• IP68 and NEMA6P;
  Survives brief periods of submersion to 1m depth
• Operating temp:
• -20 to 60 °C
• Humidity:
• 0 to 100% non-condensing
• Shock:
• MIL STD 810G - 516.6 - Shock (air transport)

• Installation

• Maximum tilt:
• ± 2°
• Orientation:
• Engraved N direction and alignment groove on sensor housing
• Features:
• Levelling via integrated precision bubble level and spiked-feet with lock handle
  ensures ease of installation. LED indicators allow quick deployment on the field