The Bently Nevada 330500-01-CN, also cataloged as the 330500 Piezo-velocity Sensor, operates as a dedicated hardware component for absolute casing vibration measurement within machinery protection systems. Configured as a self-contained piezo-electric accelerometer with internal integration electronics, it provides direct physical/electrical execution by translating structural acceleration into a proportional 4-20 mA analogue current output representing velocity.

Hardware Specifications

Turbine Supervisory Instrumentation (TSI) Performance Profiles

The 330500-01-CN piezo-velocity sensor interfaces directly with critical asset casing parameters to evaluate rotor dynamics and detect structural resonances. Unlike standard proximity probes optimized for eddy-current probe scaling and gap voltage validation (-10 VDC targets), this casing velocity transducer relies on cross-talk suppression arrays inside its internal charge amplifier to cancel structural high-frequency harmonics caused by blade-pass frequencies or gear meshing. The piezo-ceramic crystal element generates a charge proportional to acceleration, which is converted to velocity via internal analog integrators, maintaining baseline signal stability over large temperature transitions to avoid dynamic signal clipping on high-performance rotating machinery.

Technical Clarifications

Q: What are the wiring constraints when combining this sensor with an intrinsic safety barrier?

A: The sensor must be connected using a shielded, twisted pair cable with the shield grounded at the monitor end only. Interfacing through intrinsic safety barriers introduces an electrical impedance loop limit, requiring a minimum supply voltage of 17 VDC at the monitor terminal block to ensure full dynamic scale execution at maximum temperature.

Q: How does the internal electronic integration handle high-frequency mechanical shock?

A: The internal charge amplifier contains a multi-pole low-pass filter providing 24 dB per octave attenuation above 2.0 kHz. This circuit limits high-frequency spike overload from cavitation or piping noise, preventing saturation of the 4-20 mA loop electronics.

Q: Can this sensor be tested via standard field simulator injection tools?

A: Dynamic loop testing requires a calibrated physical shaker table executing a known velocity amplitude at a target baseline frequency (such as 80 Hz or 100 Hz). Electrical simulation is performed by injecting an external current block across the processing loop to verify monitor alarm relay delay thresholds.

Field Installation Guidelines

Mounting surfaces must be machined flat to a surface finish of 0.8 micrometers or better, with a minimum contact diameter of 26 mm. The 1/2-20 UNF mounting stud requires a specified torque limit of 13.5 N-m (120 in-lb) to prevent high-frequency response degradation or physical thread distortion. Avoid physical contact between the sensor body and adjacent piping to prevent external cross-talk suppression failures. Implement conduit seals and industrial potting compound on the terminal housing interface to mitigate moisture intrusion inside the sensor header plug.

Procurement Information

• 1 x Bently Nevada 330500-01-CN Piezo-velocity Sensor

• 1 x 1/2-20 UNF Thread Mounting Stud

• 1 x Calibration Certificate with individual factory sensitivity scale factor

• 1 x Standard Nitrile Weatherproof O-ring

Logistics and Packaging Data

Delivery time: 2-7 days when payment finish, routed via global premium carriers including DHL/FEDEX/UPS. All units undergo final electrical insulation checks and are vacuum sealed in anti-static industrial packaging complete with impact-absorbent polyethylene foam inserts to prevent dynamic sensor crystal degradation during transport.