Description
Key Technical Specifications
- Model Number: 330101-00-25-10-02-05
- Manufacturer: Bently Nevada (a Baker Hughes business)
- Probe Type: Eddy current (inductive) proximity sensor with integral cable
- Probe Diameter: 8mm (0.315″) – industry-standard for general machinery monitoring
- Case Length: 25mm (0.984″) – compact for tight bearing housing installations
- Unthreaded Length: 0mm – flush-mount capability for limited clearance
- Cable Configuration: 10ft (3.05m) integral cable; PFA (perfluoroalkoxy) insulation, 100% stainless steel braided shield, 22 AWG stranded copper conductors
- Connector Type: MIL-C-5015 male (mates with 3300 XL Proximitors)
- Linear Measurement Range: 4mm (0.157″) peak-to-peak
- Sensitivity: 200 mV/mm (5.08 mV/mil) typical (ferrous target, 25°C)
- Operating Temperature: -54°C to +121°C (-65°F to +250°F)
- Impedance: 50Ω (matched to 3300 XL Proximitor impedance)
- Certifications: CE, ATEX Zone 0 (Ex ia IIC T6), IECEx ia IIC T6, API 670 compliant
- Compatibility: Bently 3300 XL Proximitors, 3500 Machinery Protection System, System 1 Condition Monitoring Software
- Bend Radius: 15mm (static), 25mm (dynamic)
- Weight: 0.45kg (0.99lbs) (including 10ft cable)
Bently Nevada 330101-00-25-10-02-05
Field Application & Problem Solved
In compact rotating machinery—refinery lube oil pumps, power plant cooling fans, chemical plant auxiliary turbines—the biggest probe challenge is finding an 8mm-diameter sensor with a 25mm compact case that fits in tight bearing housings while maintaining signal integrity over a 10ft cable. Generic 8mm probes fail here: their cases are too long (30mm+), cables use brittle PVC insulation (cracking in vibration), or lack proper shielding (picking up motor/VFD noise). A Texas refinery lost $120k in a 3-hour outage when a generic probe’s 35mm case couldn’t fit in a lube pump housing, forcing improper mounting that led to inaccurate vibration data and bearing failure. A Pennsylvania power plant spent $28k annually replacing generic probes with PVC cables that degraded in high-temperature fan enclosures.
This probe solves these issues with its 25mm compact case and 10ft PFA-shielded cable. You’ll find it in: auxiliary turbine bearing housings, close-coupled centrifugal pumps, small compressor shafts—anywhere space is limited but a 10ft cable is needed to reach the proximitor. It’s the standard for retrofitting legacy compact machinery with 3300/3500 system compatibility, as its flush-mount design (0mm unthreaded length) fits in shallow mounting bores.
Its core value is compact form factor + mid-range cable reach + harsh-environment durability. Unlike generics, it’s impedance-matched to Bently proximitors (no sensitivity loss over 10ft), resists oil/chemicals with PFA insulation, and blocks EMI/RFI with 100% braided shielding. For a Louisiana chemical plant, this probe enabled monitoring of their compact reactor feed pumps—avoiding $35k in machinery modification costs and eliminating false trips from generic cable noise.
Installation & Maintenance Pitfalls (Expert Tips)
- Gap Setting: Mid-Range 2mm Is Non-Negotiable: Rookies set the gap too close (saturating the signal) or too far (losing linearity). An Ohio steel mill’s cooling fan monitor showed erratic readings until the gap was adjusted to 2mm (midpoint of the 4mm linear range). Use a precision feeler gauge—never guess based on visual alignment.
- Connector Torque: 0.8Nm (7.1 in-lbs) – Exact Value Matters: Over-torquing strips MIL connector threads; under-torquing causes intermittent signal loss. A Florida refinery’s probe failed after 4 months when the connector was torqued to 1.2Nm—invest in a torque wrench with a MIL adapter.
- Shield Grounding: Single-Point at Proximitor End Only: Grounding the shield at both probe and proximitor creates a ground loop, introducing 60Hz noise. A North Carolina refinery’s turbine data had persistent hum until we disconnected the shield from the pump housing and grounded it solely at the proximitor. Never splice the shield.
- Cable Routing: 30cm Clearance from Power Cables: Running the 10ft cable parallel to 480V+ power lines induces noise. A Michigan paper mill’s pump vibration data had 60Hz interference until the cable was rerouted through shielded conduit, 30cm away from motor power cables.
- Avoid Splicing or Extending: Rookies splice shorter cables to reach 10ft, doubling impedance and signal delay. A Texas chemical plant’s probe sensitivity dropped by 25% until we replaced the spliced setup with this integral 10ft model—splicing voids calibration and API 670 compliance.
Bently Nevada 330101-00-25-10-02-05
Technical Deep Dive & Overview
The Bently Nevada 330101-00-25-10-02-05 is a precision-engineered eddy current proximity probe designed for compact machinery monitoring. At its core, a precision-wound coil in the 8mm probe tip generates a high-frequency electromagnetic field. When a ferrous shaft (target) enters the field, eddy currents are induced in the shaft, altering the coil’s impedance. The integral 10ft cable transmits this impedance change to a 3300 XL Proximitor, which converts it into a linear voltage output (-24V to 0V) proportional to the probe-to-shaft gap—enabling accurate measurement of radial vibration, axial displacement, and eccentricity.
What sets this probe apart is its balance of compact size and signal integrity. The 25mm case length fits in tight bearing housings where longer 8mm probes can’t, while the 10ft cable provides enough reach to route around machinery without splicing. The 50Ω impedance matching ensures no sensitivity loss over the 10ft run—unlike generic probes, which often see 15-20% signal degradation at this length. The PFA insulation outperforms PVC by resisting turbine lube oil, chemical cleaners, and temperature swings, while the 100% stainless steel braid blocks interference from VFDs and motor windings.
Unlike generic 8mm probes, it’s API 670 compliant, meeting strict reliability standards for machinery protection. Its flush-mount design (0mm unthreaded length) allows installation in shallow bores, and the MIL-C-5015 connector ensures a vibration-resistant connection that won’t loosen during operation. For maintenance teams, this probe isn’t just a sensor—it’s a reliable solution for extending 3300/3500 system monitoring to compact, hard-to-reach assets. By providing accurate, noise-free data, it enables early detection of faults like bearing wear or shaft misalignment, preventing costly unplanned downtime in auxiliary machinery that’s critical to overall plant operations.
