Sensors

Available sensors include:

  • Uniaxial and triaxial force-balance accelerometers for monitoring structural vibrations
  • Linear variable differential transformers (LVDTs) for local displacement measurements

Accelerometers


110 channels of force-balance Episensor accelerometers (65 uniaxial and 15 triaxial) are available through the nees@UCLA Site. These accelerometers have a wide frequency range (DC to 200 Hz), user scalable amplitude range (+/- 0.25g to +/- 4.0g), and wide dynamic range (155 dB and 10-8 g resolution). These sensors are ideally suited for forced-vibration experiments, monitoring moderate to strong-motion events.



Uniaxial model


Triaxial model



Specifications of Episensors

Dynamic Range 155 dB+
Bandwidth DC to 200Hz
Full Scale Range User selectable at ± 0.25g, ± 0.5g, ± 1g, ± 2g or ± 4g
Outputs User selectable at: ± 2.5V single-ended; ± 10V single-ended;± 5 V differential;± 20 V differential
Linearity < 1000 µg/g2
Hysteresis < 0.1% of full scale
Cross-axis Sensitivity < 1% (including misalignment)
Zero Point Thermal Drift < 500µg/°C


Linear Variable Differential Transformers (LVDTs)


30 linear displacement measurement DC-DC LVDTs (Trans-Tek Series 240) are available through the nees@UCLA Site. The LVDT consists of a precision linear variable differential transformer, solid state oscillator and a phase-sensitive demodulator. The transducer is designed for excellent linearity, infinite resolution and high sensitivity. Input and output circuits are electrically isolated, making them usable directly in floating or ground return systems. Nominal specifications for the DC-DC LVDTs include +/- 3.0 inches, < 0.5% non-linearity, and 6 to 30 VDC excitation.