Bently Nevada 330500-07-02 Velomitor Piezo-velocity Sensor

Product Introduction

The Bently Nevada 330500-07-02 is a high-performance Velomitor Piezo-velocity Sensor for rotating machinery protection. This sensor converts mechanical vibration directly into a velocity-proportional electrical signal. Therefore, it eliminates the need for external integrators or signal conditioners. It suits a wide range of equipment including pumps, compressors, turbines, fans, and motors.

This particular model features a 3/8 – 16 UNC mounting thread. Additionally, it carries ATEX European approval (suffix -02) for hazardous area installations. For this reason, it is ideal for oil and gas, chemical, and power generation facilities requiring explosive atmosphere certification. 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 provides excellent protection against moisture, dust, and corrosion. Each unit is manufactured in the U.S.A. Moreover, it ships in original factory packaging.

Technical Specifications

The 330500-07-02 delivers accurate velocity measurements across a wide frequency range. 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. Meanwhile, 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. Consequently, it ensures accurate readings well above typical machine vibration frequencies. Temperature sensitivity varies from -14% to +7.5% typical over the full operating range. Nevertheless, this remains within acceptable limits for industrial monitoring systems.

Mechanical and Environmental Ratings

This Velomitor Piezo-velocity Sensor is engineered for demanding industrial environments. The 316L stainless steel case measures 25.3 mm (0.995 in) in diameter. In addition, it stands 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. Therefore, it offers 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. For this reason, it helps prevent ground loop issues in many installations.

Hazardous Area Approvals and Certifications

The 330500-07-02 carries comprehensive ATEX European certification for hazardous area installations. Its approvals include:

• 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. Therefore, these certifications ensure reliable operation in marine and general industrial environments.

Installation Guidelines

Installing the Bently Nevada 330500-07-02 requires proper torque and cable selection. First, mount the sensor using the 3/8-16 UNC thread. Apply a maximum torque of 32-46 kg cm (24-40 in-lb). Exceeding this torque may damage the sensor. Besides that, it could 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). Finally, 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 330500-07-02 unit comes in factory-sealed packaging. The box contains:

• 1 x Velomitor Piezo-velocity Sensor (3/8-16 UNC thread, ATEX 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. Additionally, expedited shipping options are available upon request.

Frequently Asked Questions

1. What does the ATEX approval allow me to do?
The -02 suffix provides ATEX certification for Zone 0, 1, and 2 hazardous areas. Therefore, you can install this sensor in explosive atmospheres across European and many international facilities.

2. What is the difference between the 3/8-16 UNC and other thread options?
This thread size offers a balance between mounting strength and compactness. Specifically, it is larger than M8 x 1 but smaller than 5/8-18 UNF, making it suitable for medium-sized machinery.

3. Can I use this sensor with an extension cable?
Yes. However, the total cable length should not exceed 305 meters (1,000 feet) to avoid signal degradation. For high-vibration applications, keep the length under 63 meters (208 feet).

4. How do I verify the sensor is working correctly?
First, measure the output bias voltage between Pin A and Pin B. It should read -12 ±3.0 VDC. Additionally, you can verify sensitivity using a portable vibration calibrator.

5. Is this sensor compatible with non-Bently Nevada monitoring systems?
Yes, provided the system accepts a piezo-velocity sensor input with 100 mV/in/s sensitivity and -12 VDC bias voltage. However, always confirm compatibility specifications before installation.