Overview

The Bently Nevada Velomitor Piezo-Velocity Sensor, specifically the 330500 model, is designed for measuring absolute vibration levels (relative to free space) in bearing housings, casings, or structural components. This specialized piezoelectric accelerometer integrates solid-state electronics, making it a durable and highly accurate solution for vibration monitoring.

Specifications

Electrical

• Sensitivity: 3.94 mV/mm/s (100 mV/in/s) ±5%
• Frequency Response:
  • 4.5 Hz to 5 kHz (270 cpm to 300 kcpm) ±3.0 dB
  • 6.0 Hz to 2.5 kHz (360 cpm to 150 kcpm) ±0.9 dB
• Temperature Sensitivity: -14% to +7.5% typical over the operating temperature range
• Velocity Range: 1270 mm/s (50 in/s) peak
• Transverse Sensitivity: Less than 5% of sensitivity
• Amplitude Linearity: ±2% to 152 mm/s (6 in/s) peak
• Mounted Resonant Frequency: Greater than 12 kHz
• Output Bias Voltage: -12 ±3.0 VDC, referenced to Pin A over temperature
• Dynamic Output Impedance: Less than 2400 Ω
• Broadband Noise Floor: 0.004 mm/s (160 μin/s) rms (4.5 Hz to 5 kHz)
• Grounding: Case isolated
• Maximum Cable Length: 305 meters (1,000 feet) of cable (Part No. 02173006) without signal degradation

Environmental Limits

• Operating Temperature Range: -55°C to 121°C (-67°F to 250°F)
• Shock Survivability: 5,000 g peak maximum
• Relative Humidity: 100% (non-submerged), case is hermetically sealed

Physical

• Weight: 142 grams (5.0 oz) typical
• Diameter: 25.3 mm (0.995 in)
• Height: 63.2 mm (2.49 in)
• Case Material: 316L stainless steel
• Connector: 2-pin Mil-C-5015, hermetically sealed, 316L stainless steel shell
• Mounting Torque: 32-46 kg cm (24-40 in-lb) max
• Polarity: When the sensor case motion is towards the connector, Pin A becomes positive with respect to Pin B

Output Characteristics

• Inrush Current: 3 Amps for 10 ms without triggering ESCP trip
• Output Voltage Drop: 0.3 V DC maximum
• Steady-State Overcurrent Trip: 5 Amps typical per point
• Output Leakage Current: 0.1 mA maximum
• On Response Time: 0.5 ms maximum
• Off Response Time: 0.5 ms maximum
• Protection: Short-circuit protection, overcurrent protection, overtemperature protection, all with auto recovery

Additional Features

• Base Strain Sensitivity: 0.005 in/s/mstrain
• Magnetic Field Susceptibility: < 51 min/s/gauss (at 50 gauss, 50-60 Hz)