Bently Nevada 330500-04-01 Velomitor Piezo-velocity Sensor

Product Introduction

The Bently Nevada 330500-04-01 is a precision Velomitor Piezo-velocity Sensor engineered for rotating machinery protection. This sensor converts mechanical vibration directly into a velocity-proportional electrical signal, eliminating the need for external signal conditioning. It serves critical applications in pumps, compressors, turbines, and fans across power generation, oil and gas, and manufacturing industries.

This particular model features a 1/4-20 UNC mounting thread and carries CSA/US/C approval (suffix -01) for use in North American hazardous locations. The sensor operates reliably across extreme temperatures from -55°C to 121°C (-67°F to 250°F). Furthermore, its hermetically-sealed 316L stainless steel case resists moisture, dust, and corrosive agents. Each unit is manufactured in the U.S.A. and ships in original factory packaging.

Technical Specifications

The 330500-04-01 provides accurate velocity measurements across a wide frequency spectrum. Its electrical sensitivity is rated at 3.94 mV/mm/s (100 mV/in/s) ±5% at 100 Hz reference. Frequency response spans 4.5 Hz to 5 kHz (270 cpm to 300 kcpm) with ±3.0 dB tolerance, while the narrower band of 6.0 Hz to 2.5 kHz (360 cpm to 150 kcpm) achieves ±0.9 dB precision for critical monitoring applications.

Key electrical parameters:

• Velocity range: 1270 mm/s (50 in/s) peak

• Output bias voltage: -12 ±3.0 VDC referenced to Pin A

• Dynamic output impedance: Less than 2400 Ω

• Broadband noise floor (4.5 Hz to 5 kHz): 0.004 mm/s rms nominal

• Amplitude linearity: ±2% to 152 mm/s (6 in/s) peak

• Transverse sensitivity: Less than 5% of sensitivity

The mounted resonant frequency exceeds 12 kHz, ensuring accurate readings well above typical machine vibration frequencies. Temperature sensitivity varies from -14% to +7.5% typical over the full operating range, which remains within acceptable parameters for industrial monitoring systems.

Mechanical and Environmental Ratings

This Velomitor Piezo-velocity Sensor is built to withstand demanding industrial environments. The 316L stainless steel case measures 25.3 mm (0.995 in) in diameter and 63.2 mm (2.49 in) in height. It weighs approximately 142 grams (5.0 oz). The 2-pin Mil-C-5015 connector features a hermetically-sealed 316L stainless steel shell for maximum environmental protection.

Environmental limits:

• Operating temperature: -55°C to 121°C (-67°F to 250°F)

• Shock survivability: 5,000 g peak maximum

• Relative humidity: Up to 100% non-submerged (case is hermetically-sealed)

Additionally, the sensor offers excellent immunity to interference. Base strain sensitivity is rated at 0.005 in/s/mstrain. Magnetic field susceptibility measures less than 51 min/s/gauss at 50 gauss, 50-60Hz. The case is isolated from ground, which helps prevent ground loop issues in many installations.

Hazardous Area Approvals and Certifications

The 330500-04-01 carries comprehensive hazardous area approvals for North American installations. Its CSA/US/C certification covers:

• Ex ia IIC T4 and AEx ia IIC T4 (intrinsic safety)

• Class I, Division 1, Groups A, B, C and D

• Class II, Groups E, F, G

• Class III

• Ex nL IIC T4 and AEx nA IIC T4 (non-incendive)

• Class I, Div 2, Groups A, B, C, D

Temperature classification is T4 for ambient temperatures from -40°C to 100°C. Installation must follow drawing 167537. Furthermore, the sensor complies with FCC Part 15, EMC Directive 2014/30/EU, and RoHS Directive 2011/65/EU. Maritime approvals from DNV cover ships, high-speed craft, and offshore standards.

Installation Guidelines

Installing the Bently Nevada 330500-04-01 requires proper torque and cable selection. Mount the sensor using the 1/4-20 UNC thread with a maximum torque of 32-46 kg cm (24-40 in-lb). Exceeding this torque may damage the sensor or affect its performance characteristics.

For the cable, use part number 02173006 or equivalent 2-conductor shielded cable. The maximum cable length is 305 meters (1,000 feet) without signal degradation. However, for installations with high vibration (50g at 10 kHz) and cable capacitance of 200 pF/m, the recommended length is 208 feet (63 meters). Always observe polarity: when the sensor case moves toward the connector, Pin A becomes positive with respect to Pin B.

Packaging List

Each new original 330500-04-01 unit comes in factory-sealed packaging. The box contains:

• 1 x Velomitor Piezo-velocity Sensor (1/4-20 UNC thread, CSA/US/C approved)

• 1 x Mounting instruction sheet

Note: Certificates and warranty documents are not included in the package.

Shipping Information

All orders ship via FedEx, UPS, or DHL with full tracking. International delivery typically takes 3–7 business days. Expedited shipping options are available upon request.

Frequently Asked Questions

1. What is the difference between the -01 and -02 agency approval options?
The -01 suffix indicates CSA/US/C approval for North American hazardous areas. The -02 suffix provides ATEX European certification. Both offer similar intrinsic safety and non-incendive protection levels.

2. Can I mount this sensor vertically or horizontally?
Yes. The 330500-04-01 works in any orientation. However, always ensure the mounting surface is flat and clean to achieve proper torque and accurate readings.

3. What cable type should I use with this sensor?
Use Bently Nevada part number 02173006 or a 2-conductor shielded cable with similar specifications. The maximum length is 305 meters (1,000 feet) without signal degradation.

4. How do I verify the sensor is working correctly?
Measure the output bias voltage between Pin A and Pin B. It should read -12 ±3.0 VDC. Additionally, check sensitivity using a known vibration source or calibrator.

5. Is this sensor suitable for submersible applications?
No. While the case is hermetically-sealed and handles 100% humidity, it is not designed for continuous submersion. Use it in non-submerged environments only.