Description
Bently Nevada 330851-02-000-070-50-00-05
Technical Specifications:
- Product Series: 3300 XL 25mm Eddy Current Sensor System
- Probe Diameter: 25mm
- Thread Specification: M30×2 Thread
- Unthreaded Length: 000 = 0mm
- Overall Case Length: 070 = 70mm
- Total Cable Length: 50 = 5.0 meters
- Armor Option: 00 = No armor
- Agency Approval: 05 = Multiple certifications
Functional Features:
- 25mm sensing diameter provides a 12.7mm (500 mils) linear range, the largest in the 3300 XL family
- Designed to withstand continuous operation at temperatures up to 200°C (392°F)
- Can tolerate intermittent temperatures up to 250°C (482°F)
- Front and rear sealing combined with FluidLoc cable prevents moisture ingress at the probe tip
- High-temperature ClickLoc connector is standard on all 25mm probes
- Each probe and cable ships with a connector protector and disposable installation tool
Application Scenarios:
- Differential expansion (DE) measurement on medium to large steam turbines
- Measurement of expansion differences between turbine rotor and machine casing (stator)
- DE measurement implemented using two eddy current sensors measuring a flange or taper at a distance from the thrust bearing
- Power generation steam turbine monitoring
Performance Parameters:
- Sensitivity: 0.787 V/mm (20 mV/mil)
- Linear Range: 12.7mm (500 mils), from 0.63mm to 13.33mm (25 to 525 mils)
- Frequency Response: 0 to 2.7 kHz, typical +0 to -3dB
- Supply Voltage: -17.5 VDC to -26 VDC
- Recommended Minimum Target Size: 61mm (2.4 inch) diameter flat target
- Maximum Cable Run from Proximitor to Monitor: 305 meters (1000 feet)
Material Composition:
- Probe Tip: High-temperature resistant material
- Probe Housing: Stainless steel
- Cable: FluidLoc cable (standard on all 25mm probes), Teflon-insulated
Structural Features:
- M30×2 threaded case for robust mounting
- 70mm overall case length
- 5.0-meter integral FluidLoc cable
- High-temperature ClickLoc connector with removable collar for routing through tight spaces
- Front and rear sealing design
Working Principle: Based on the eddy current effect, the 25mm probe coil generates a high-frequency alternating magnetic field. When a conductive target surface enters the magnetic field range, eddy currents are induced. The reverse magnetic field from these eddy currents alters the coil impedance, and the proximitor converts this impedance change into a voltage signal proportional to the gap distance. The larger 25mm diameter provides a proportionally larger linear measurement range.
Installation Requirements:
- The mounting hole must be machined with M30×2 internal thread
- Total system length (probe cable + extension cable) must match the proximitor’s nominal length
- DE measurement requires two sensors measuring a flange or taper surface at a known distance from the thrust bearing
- Target surface must be at least 61mm in diameter
Usage Precautions:
- The FluidLoc cable must not be damaged, as it provides the primary moisture barrier
- The removable collar on the ClickLoc connector must be properly reinstalled after cable routing
- Connector protectors must remain installed until final connection
- High-temperature operation requires verification that all system components are rated for the operating temperature
