| Feature |
3300 Series (Legacy) |
3300 XL Series (Current) |
| Connector Type |
Brass / Stainless Steel |
Gold-plated ClickLoc™ (Tool-less) |
| Probe Tip Bond |
Adhesive / Epoxy |
TipLoc™ Molded Interlock |
| Cable Attachment |
Standard Crimp |
CableLoc™ (75 lbf pull strength) |
| Interchangeability |
Matched Sets Often Required |
Fully Interchangeable (Gold Standard) |
| RFI Immunity |
Requires Metal Housing |
High (CE Compliant / No Housing) |
| Oil Sealing |
External Compression Only |
FluidLoc Cable Option Available |
| Terminal Strip |
Screw Type |
SpringLoc™ (Vibration Proof) |
| Temperature Range |
Standard |
Extended Temperature Range (ETR) Options |
| Availability |
Discontinued / Surplus |
Active / Global Stock |
Machinery health relies on precise vibration data. The evolution from Bently Nevada 3300 series to 3300 XL represents a massive leap in reliability and mechanical integrity. Understanding the distinctions clarifies maintenance strategies for critical assets while highlighting the benefits of modern proximity probes in industrial environments.
The Physics of Invisible Detection
To comprehend the shift from the legacy 3300 to the advanced 3300 XL, one must first grasp the unseen forces at play. Proximity probes operate via electromagnetic induction. A coil within the probe tip generates a radio frequency field. When a conductive shaft cuts through the field, eddy currents form on the surface. These currents extract energy from the field, modulating the voltage. The system translates the modulation into a readable gap distance.
Reliability engineers crave high sensor accuracy and a reliable sensor range. In the past, achieving such precision required the painstaking matching of components. The 3300 series set the standard, yet the 3300 XL redefined the possibilities through advanced materials science and manufacturing consistency.
Mechanical Fortification: 3300 XL Innovations
The most visible differences lie in the physical construction. The 3300 XL series introduces patented technologies designed to eliminate common failure modes found in the older 3300 line.
TipLoc™ Technology
Probe tips often separate from the probe body due to thermal cycling. The legacy 3300 probes relied on adhesive bonds. Over time, the expansion mismatch between the plastic tip and the stainless steel case would shear the glue, causing the tip to detach. The 3300 XL utilizes TipLoc™ molding. The process creates a mechanical interlock between the tip and the body. The design eliminates adhesive failures, guaranteeing the tip remains secure even in extreme heat.
CableLoc™ Technology
Cabling remains the Achilles' heel of instrumentation. Pulling a cable through a conduit often subjects the connection to immense strain. The 3300 XL incorporates CableLoc™ design, providing a pull strength of 330 N (75 lbf) where the cable attaches to the probe. Such robustness prevents separation during installation, a frequent issue with the non-XL 3300 equivalents.
ClickLoc™ Connectors
Corrosion and loosening connections plagued the standard 3300 systems. Brass connectors would oxidize, altering the resistance and causing signal drift. The 3300 XL features gold-plated ClickLoc™ connectors. These components lock into place with an audible snap, preventing back-off due to vibration. Gold plating eliminates corrosion, preserving the integrity of the signal in humid environments. Furthermore, the design requires no tools, rendering installation faster and safer for the hardware.
Interchangeability and The Gold Standard
The 3300 series often required the matching of probes, cables, and Proximitors to meet API 670 specifications. If a user replaced a probe, the system often needed recalibration to verify the sensor accuracy.
The 3300 XL series adheres to the "Gold Standard" of interchangeability. Manufacturing tolerances are so tight that any 3300 XL probe works with any 3300 XL extension cable and Proximitor. The system maintains a standard scale factor (typically 200 mV/mil) without bench calibration. Such flexibility simplifies spare parts inventory and reduces downtime during outages.
Environmental Armor: FluidLoc and RFI Immunity
Industrial environments assault sensors with oil, heat, and electromagnetic noise. The 3300 XL series offers superior defenses compared to the predecessor.
FluidLoc Capability
High-pressure oil can wick through the interior of standard coaxial cables, traveling from the machine case to the junction box. The 3300 XL offers the FluidLoc cable option. A dedicated sealing barrier within the cable prevents oil ingress, keeping the control room clean and safe. The legacy 3300 series lacked internal sealing of that caliber.
Radio Frequency Interference (RFI)
Modern plants teem with variable frequency drives and wireless communication devices. The older 3300 Proximitors were susceptible to RFI, often requiring bulky metal conduit boxes for shielding. The 3300 XL Proximitor incorporates advanced filtering and a multi-layer board design. It meets European CE standards for electromagnetic compatibility without extra housing, reducing installation costs and complexity.
Specific Application Variants
While the 8mm system serves as the workhorse, specialized variants exist for unique constraints.
The 5mm System
Space restrictions sometimes preclude the use of an 8mm probe. The 3300 XL 5mm system utilizes a smaller tip but pairs it with the standard XL 8mm extension cable and Proximitor. The legacy 3300 5mm system required dedicated cabling. The XL approach streamlines inventory via shared components.
Narrow Side View (NSv)
For tight counterbores where the magnetic field might interact with the side walls, the 3300 XL NSv system replaces the older 3300 RAM system. The NSv probe emits a focused field, allowing for accurate sensor range measurement in restricted spaces. Users must note that NSv components are not interchangeable with standard XL parts; the physics of the focused field demand a matched set of probe, cable, and driver.
Sourcing and Lifecycle Management
With the 3300 series in obsolescence, facilities face a challenge: how to maintain legacy loops without immediate capital for full upgrades. Suppliers like Apter Power bridge the gap. They stock discontinued 3300 components alongside new 3300 XL parts.
Apter Power provides a critical lifeline for US operations. If a legacy 3300 Proximitor fails, sourcing a replacement from the OEM might be impossible. Apter Power maintains an inventory of hard-to-find parts, allowing plants to replace a single failed unit rather than forcing a complete system retrofit. Their immediate dispatch and warranty services offer peace of mind to reliability managers balancing budget and uptime.
For those upgrading, Apter Power also supplies the 3300 XL components. Moving to the XL line is the logical step for long-term reliability. The XL components are backward compatible with non-XL 3300 probes electrically, allowing for a phased migration. A plant can install a 3300 XL Proximitor today to drive an existing 3300 probe, gaining improved RFI immunity immediately while planning for eventual probe replacement.
3300 XL vs Legacy 3300: Making the Right Upgrade Decision
Upgrading to 3300 XL proximity probes guarantees superior data fidelity and mechanical survival. While legacy 3300 series systems fade, the 3300 XL offers extended sensor range and robust sensor accuracy through features like TipLoc and ClickLoc. Partners like Apter Power bridge the gap, supplying critical components to keep operations running smoothly.
Videos
News
Applications
