Description
The 330500-01-00 specifies a Bently Nevada Velomitor Piezo-Velocity Sensor configured with a standard 1/2-20 UNF mounting stud and no regulatory hazardous area approvals.
Unlike traditional moving-coil velocity transducers, the Velomitor is a specialized solid-state device containing an internal piezoelectric accelerometer paired with an embedded electronic integrator circuit. It outputs a voltage signal directly proportional to absolute machine housing vibration velocity, making it an industry standard for monitoring casing vibrations on equipment with rolling-element bearings, such as pumps, motors, and small fans.
The specific options defined by the -01-00 suffix break down as follows:
- -01 (Mounting Stud Option): Includes a 1/2-20 UNF threaded mounting adapter stud.
- -00 (Agency Approval Option): Standard non-hazardous area configuration (No agency approvals).
Technical Specifications
| Parameter | Specification / Value |
| Brand | Bently Nevada (Baker Hughes) |
| Model / Type | 330500 Velomitor Piezo-Velocity Sensor |
| Part Number Configuration | 330500-01-00 |
| Scale Factor / Sensitivity | 3.94 mV/mm/s (100 mV/in/s) ±5% at 100 Hz |
| Frequency Response | 4.5 Hz to 5.0 kHz (±3.0 dB)
6.0 Hz to 2.5 kHz (±0.9 dB) |
| Electrical Connection | Integrated 2-pin top connector (MIL-C-5015 style) |
| Excitation Voltage Requirements | 22 to 30 V DC (provided via external constant current source) |
| Constant Current Supply Range | 2.5 to 6.0 mA (10 mA maximum peak) |
| Velocity Range Peak | 1,270 mm/s (50 in/s) peak |
| Case Material | 316L Stainless Steel, hermetically sealed |
| Operating Temperature | −40 to +121 °C (−40 to +250 °F) |
Field Application and System Integration Notes
Electrical Wiring and Constant Current Supply
The 330500-01-00 operates as a loop-powered, two-wire constant-current device.
- Pin A carries the positive supply voltage and the superimposed AC vibration signal. Pin B acts as the system return.
- Warning: Never connect the Velomitor directly to a standard raw DC power supply without a constant-current diode or regulating circuit interface. Doing so will instantly burn out the internal integrating electronics.
- Monitoring Interfaces: Standard rack modules like the Bently Nevada 3500/42M or 3500/40M monitors have integrated internal current-limiting sources configured specifically for Velomitor type sensors, eliminating the need for standalone external barriers.
Mechanical Installation and Resonance Risks
- Torque Rating: The sensor housing must be torqued to exactly 4.5 Nm (40 in-lb) using a calibrated torque wrench. Under-torquing reduces high-frequency response accuracy by decoupling the sensor body from the machine housing, while over-torquing permanently distorts the internal crystal sensor base plate.
- Perpendicularity: Ensure the drilled and tapped face on the machine casing is perfectly flat and perpendicular to within 0.02 mm (0.001 in) relative to the bolt hole centerline to prevent multi-axis cross-talk interference.
Commercial and Procurement Data
- Product Condition: New Original (Factory Sealed) or Refurbished/Tested Surplus.
- Standard Warranty: 12-month comprehensive depot warranty from distribution shipping date.
- Estimated Lead Time: In-stock configurations ship within 1 to 2 business days.
- Pricing Notice: Price varies based on supply cycles, wholesale quantities, and test validation certificate requests. Contact our procurement desk for a formalized, itemized price quote.
