Product Overview

The Bently Nevada 124761-01 is a precision 8mm eddy current proximity probe, part of the industry-standard 3300 XL series. Designed for non-contact measurement of shaft vibration, axial position, and rotational speed, this probe serves as the fundamental sensing element in machinery protection and condition monitoring systems. Its integral 5-meter cable design ensures factory-calibrated performance and eliminates field connection errors that can compromise measurement accuracy.

Operating on eddy current principles, the probe generates a low-power radio frequency field that interacts with the target shaft surface. Changes in the gap between probe tip and shaft modulate this field, producing a signal that is conditioned by a compatible Proximitor to provide a DC voltage proportional to displacement. This reliable technology has made the 124761-01 a standard choice for protecting critical rotating equipment across multiple industries .

Key Features

• 8mm diameter sensing tip for standard measurement applications

• Integral 5-meter cable – factory calibrated for consistent sensitivity

• Sensitivity: -7.87 V/mm (200 mV/mil) nominal,API 670 requirements

• Linear measurement range: 2.0 mm (80 mils)

• M10 x 1.0 standard mounting thread for industry-wide compatibility

• Stainless steel housing with rugged polyurethane cable jacket

• High temperature capability: -30°C to +177°C at probe tip

Technical Specifications

• Model: 124761-01

• Product Type: Eddy current proximity probe (3300 XL series)

• Probe Diameter: 8 mm

• Cable Length: 5 meters, integral (non-removable)

• Sensitivity: -7.87 V/mm ±5% (200 mV/mil) 

• Linear Range: 0.25 to 2.3 mm (10 to 90 mils) typical

• Frequency Response: 0 to 10 kHz

• Mounting Thread: M10 x 1.0

• Operating Temperature (Probe Tip): -30°C to +177°C

• Cable Jacket: Polyurethane, oil-resistant, abrasion-resistant

• Linearity: ≤ ±0.5% of full scale

• Compliance: API 670, CE, RoHS

Applications

The 124761-01 is used extensively in critical machinery monitoring applications:

• Radial vibration measurement on turbine, compressor, and generator bearings

• Axial (thrust) position monitoring for rotating shafts

• Keyphasor® reference for speed and phase measurement

• Eccentricity monitoring during startup and coastdown

• Power generation (gas turbines, steam turbines, hydro generators)

• Oil and gas (compressors, pumps, expanders)

• Petrochemical and refining (critical rotating equipment)

Benefits

The 124761-01 offers significant advantages through its integral cable design. By eliminating field-installed connectors, it removes potential points of signal degradation, moisture ingress, and impedance mismatch that can plague field-assembled systems. The factory calibration ensures that sensitivity remains consistent throughout the probe's service life, providing trustworthy data for protection systems. Its M10 x 1.0 mounting thread is an industry standard, ensuring compatibility with existing installations worldwide. The rugged construction, including stainless steel housing and oil-resistant polyurethane cable, ensures reliable operation in harsh industrial environments. When paired with matching 5-meter Proximitors, the 124761-01 forms a complete sensing system that meets the stringent requirements of API 670 for machinery protection.

Conclusion

The Bently Nevada 124761-01 8mm proximity probe represents the gold standard for non-contact shaft measurement in critical machinery applications. Its proven design, factory-calibrated accuracy, and robust construction make it the preferred choice for protecting valuable rotating assets worldwide.