Bently Nevada 21508-02-12-05-02 8mm Reverse Mount Probe

The Bently Nevada 21508-02-12-05-02 is a reverse-mount proximity probe designed for high-precision non-contact measurement of shaft vibration and position in rotating machinery. As part of the renowned 3300 XL series, this 8mm eddy current sensor is specially engineered for applications where front access to the machine shaft is restricted or impossible.

It is commonly paired with matching extension cables and proximity transducers (Proximitor® sensors) to form a complete measurement chain. Designed with robustness, linear accuracy, and environmental resilience, the 21508-02-12-05-02 is a trusted solution in industries such as oil & gas, power generation, and heavy equipment manufacturing. This reverse-mount configuration is particularly valuable in tight, enclosed, or high-temperature machinery environments.

Product Specifications

Applications

The 21508-02-12-05-02 Reverse Mount Probe is a purpose-built solution for scenarios where standard front-mount probes are unsuitable or physically obstructed. This makes it indispensable in a variety of high-performance industrial sectors:

1. Steam & Gas Turbines

   Reverse mounting is often required in bearing housings or turbine enclosures where space is restricted or sealed.

2. Compressors

   Used in centrifugal and reciprocating compressors to monitor shaft displacement and rotor dynamics.

3. Pumps and Motors

   Ideal for enclosed motors or submerged pumps where only rear access to the shaft is available.

4. Gearboxes and Speed Reducers

   Enables accurate monitoring of gear shaft vibration and alignment without disturbing the housing.

5. High-Speed Rotating Equipment

   Ensures precision in dynamic environments where traditional probes may face physical damage or interference.

6. OEM Machinery Integration

   Preferred by machine builders who require compact, internally mounted monitoring solutions.

Product Advantages

The Bently Nevada 21508-02-12-05-02 proximity probe offers several technical and operational advantages:

1. Reverse Mount Design

   Enables installation in challenging layouts, such as sealed or rear-access housings.

2. Robust Construction

   Made with high-grade stainless steel, the probe is corrosion-resistant and suitable for harsh environments.

3. High Accuracy and Linearity

   Offers consistent and precise measurements with minimal deviation across its full range.

4. Wide Compatibility

   Easily integrates with Bently Nevada 3300 XL Proximitor modules and extension cables.

5. API 670 Compliance

   Meets industry-standard specifications for critical machinery protection.

6. Reliable in Harsh Environments

   With an IP65 rating and broad operating temperature range, it performs reliably in dusty, humid, or high-temperature locations.

7. Easy Maintenance

   Modular design enables simple probe replacement without disturbing other system components.

8. Low Signal Noise

   Excellent EMI shielding ensures accurate readings even in electrically noisy environments.

9. Long-Term Stability

   Maintains calibration and accuracy over long operating lifespans, reducing maintenance frequency.

10. Trusted Brand

    Manufactured by Bently Nevada, a global leader in condition monitoring and vibration sensing technologies.

Frequently Asked Questions (FAQ)

1. What is a reverse mount proximity probe?

   – A reverse mount probe is designed to be installed from the opposite side of the shaft, ideal for restricted or enclosed areas.

2. Is this probe compatible with the 3300 XL Proximitor modules?

   – Yes, it is fully compatible with Bently Nevada’s 3300 XL series Proximitor units.

3. What is the measurement range of the 21508-02-12-05-02?

   – It has a nominal range of 2 mm with a linear operating range up to 2.5 mm.

4. Can I use this probe in high-temperature environments?

   – Yes, it operates reliably between -35°C to +120°C, and can be stored at up to +150°C.

5. What’s the difference between this and a standard front-mount probe?

   – This model is mounted from the rear or side, offering installation flexibility in inaccessible or confined areas.

6. What is the environmental protection rating of this probe?

   – It has an IP65 rating, protecting against dust and low-pressure water jets.

7. What type of signal does the probe output?

   – The probe itself works with a Proximitor module to produce an analog voltage signal proportional to shaft displacement.

8. Can this be used in hazardous or explosive environments?

   – With appropriate system-level certifications and accessories, it can be used in ATEX-rated environments.

9. Is this probe part of a system or standalone?

   – It is part of a three-component system: probe, extension cable, and Proximitor.

10. How is the probe installed?

    – It is mounted via a reverse-threaded insert, secured from the internal side of the equipment housing.