
Technical Overview
The Bently Nevada 21502-04 Velomitor Piezo-Velocity Sensor is a self-generating, industrial-grade vibration sensor that produces a voltage signal proportional to vibration velocity. Designed for long-term monitoring of casing or housing vibration, it is a key component in machinery protection systems used in power generation, oil & gas, and petrochemical industries.
This model combines the ruggedness of a piezoelectric velocity transducer with the precision required for predictive maintenance. Its stainless-steel enclosure, wide operating temperature range, and factory calibration ensure dependable performance even in harsh field conditions.
Technical Specifications
| Parameter | Description |
|---|---|
| Model Number | 21502-04 |
| Module Type | Velomitor Piezo-Velocity Sensor |
| Measurement Type | Vibration Velocity (mm/s or in/s) |
| Sensitivity | 100 mV/in/s ±5% (nominal) |
| Frequency Range | 4.5 Hz to 5 kHz |
| Power Supply | +23 to +36 V DC (constant current source) |
| Output Signal | Single-ended voltage |
| Mounting Type | Stud mount (1/4-28 UNF thread) |
| Housing Material | Stainless steel |
| Connector Type | 2-pin MIL-C-5015 compatible |
| Temperature Range | –54 °C to +121 °C |
| Shock Limit | 5000 g peak |
| Sealing | Hermetically sealed (IP65 equivalent) |
| Typical Dimensions | 90 mm × 35 mm × 120 mm |
| Weight | 0.30 kg |
Applications / Use Scenarios
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Turbomachinery casing vibration monitoring (compressors, turbines, pumps).
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Integration with Bently Nevada 3500/42M or 1900/65A vibration monitoring modules.
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Condition-based maintenance programs in refineries and power plants.
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Retrofit applications replacing older velocity transducers.
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Monitoring machine foundation vibration in high-power rotating equipment.
Advantages / Key Engineering Features
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High Reliability: Proven piezoelectric design ensures long operational life.
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Excellent Frequency Response: Captures both low- and high-frequency vibrations accurately.
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Hermetically Sealed Construction: Prevents ingress of oil, moisture, and dust.
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No Moving Parts: Ensures long-term calibration stability with minimal maintenance.
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Shock & Temperature Resistant: Performs consistently in demanding environments.
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Plug-and-Play Integration: Fully compatible with Bently Nevada monitoring systems.
Excellent PLC
