Overview

The Bently Nevada Seismoprobe Velocity Transducer Systems are designed to measure absolute vibration (relative to free space) in bearing housings, casings, or structural components. These two-wire systems consist of a transducer and the appropriate cable. Utilizing moving-coil technology, the Seismoprobe transducer generates a voltage output directly proportional to the vibration velocity it detects.

Specifications

Electrical

• Sensitivity: 20 mV/mm/s (500 mV/in/s), ±5% when properly terminated and oriented at the calibration angle.
• Calibration Load: 10 kΩ across pins "A" and "B" (output taken between pins A and B).
• Sensitivity Temperature Coefficient: 0.2%/°C.
• Frequency Response: From minimum operating frequency to 1 kHz (60,000 cpm); +0, -3dB typical. For detailed calibration data, please contact Bently Nevada.
• Dynamic Operating Range: Maximum displacement of 2.54 mm (0.100 in) peak-to-peak.
• Velocity Range: 25 mm/s (1 in/s) at +22°C casing vibration at 100 Hz with a 10 kΩ load.
• Coil Resistance: 1.25 kΩ ±5%.
• Locked Coil Inductance: 125 mH (typical).
• Amplitude Linearity: ±5% from 0.01 to 5.0 in/s (0.254 to 127 mm/s) at 100 Hz (6000 cpm).
• Shock Resistance: Withstands 50 g peak maximum acceleration along the non-sensitive axis.
• Transverse Sensitivity: ±10% maximum of the sensitive axis sensitivity at 100 Hz and 1.0 in/s (2.54 cm/s).
• Polarity of Output Signal: Pin A is positive relative to Pin B when the transducer case velocity moves towards the connector.
• Lead Wire Length: Maximum 305 meters (1,000 feet) between the Seismoprobe Velocity Transducer and 3300 or 3500 Monitor. Refer to the manual for frequency roll-off at longer lengths.

Environmental Limits

• Operating and Storage Temperature:
  • Model 9200: -29°C to +121°C (-20°F to +250°F).
  • Model 74712: -29°C to +204°C (-20°F to +400°F).
• Relative Humidity: Up to 95% non-condensing, 100% when ordered with integral cable (non-submerged).

Mechanical

• Case and Adapter Material: Anodized aluminum (A204).
• Gasket Material:
  • Model 9200: Neoprene.
  • Model 74712: Silicone.
• Connector Material: Options available in cadmium-plated aluminum, neoprene, and silver-plated copper.
• Terminal Block Option: Polyphenylene sulfide with nickel-plated copper contacts.
• Mounting Torque:
  • 1/2-20, 1/4-20, 1/4-28, 5/8-18, or M10X1 mounting base options: 5.6 N·m (50 in·lb).
  • 8-32 threaded studs: 1.41 N·m (12.5 in·lb).

Physical

• Height: 102 mm (4 in) typical (depending on connector option).
• Diameter: 41 mm (1.6 in) typical.
• Weight:
  • Model 9200: 300 grams (10.5 ounces) typical.
  • Model 74712: 480 grams (17 ounces) typical.