The Bently Nevada 330100-90-01, also cataloged as the 330100 proximity probe, operates as a dedicated hardware component for non-contacting displacement measurement within the 3300 XL eddy current transducer system. It generates an RF signal to detect ferrous target position via electromagnetic induction, outputting a linear DC voltage proportional to shaft proximity.
Suffix Breakdown & Model Matrix
Suffix
Definition
330100
Base model: 3300 XL 8mm probe, 3/8-24 UNF threads
-90
Unthreaded length: 9.0 inches
-01
Total case length: 1.0 inch
Hardware Specifications
Parameter
Specification
Model Brand
Bently Nevada 330100-90-01
Origin
USA
Weight
Approx. 0.15 kg (probe assembly)
Dimensions
Thread: 3/8-24 UNF; Case L: 1.0 in; Unthreaded L: 9.0 in
Operating Temp
-51 degC to +177 degC
Power Consumption
Passive device; powered via external Proximitor
Linear Range
2.0 mm (80 mils)
Scale Factor
7.87 V/mm (200 mV/mil) ±5% (AISI 4140)
Frequency Response
0 Hz to 10 kHz (+0, -3 dB)
Probe Tip Material
Polyphenylene sulfide (PPS)
Case Material
303 Stainless Steel
Eddy-Current Probe Scaling and Gap Validation
The probe exhibits a scale factor of 7.87 V/mm when calibrated against AISI 4140 steel targets. During installation, gap voltage validation must target -10 VDC at the Proximitor terminal to ensure the target resides within the linear range. The system suppresses cross-talk between adjacent probes by maintaining a minimum separation distance equal to the probe diameter (8 mm) plus 25.4 mm. Signal linearity degrades if the target surface finish exceeds 63 micro-inches RMS or if non-ferrous materials alter the eddy-current damping characteristics.
Frequently Asked Questions
Q: Does the probe require calibration when replacing a failed unit in the field?
A: No. The 3300 XL probes are mechanically and electrically interchangeable without field calibration. Calibration is performed at the factory; swap the probe and verify the -10 VDC gap voltage at the monitor.
Q: What is the maximum permissible cable bend radius during installation?
A: Maintain a minimum bend radius of 25.4 mm (1.0 inch) for the probe's integral coaxial cable to prevent dielectric insulation failure and signal attenuation.
Q: Can this probe be submerged in oil?
A: Submersion is permitted only when the probe-to-cable connector interface is protected by a certified epoxy boot or heat-shrink sealing. Without sealing, operation is limited to 100% condensing humidity environments.
Field Installation Guidelines
Install the probe ensuring the threads engage a minimum of five full turns into the machined mounting bracket. Torque the locknut to 8-10 N-m (71-89 in-lb) to prevent vibrational loosening. Ground the probe shield drain wire directly to the machine case at the entry point to the junction box; do not ground at both ends to avoid ground loops. Verify clearance between the probe tip and the rotating shaft does not fall below 0.25 mm (10 mils) during maximum excursion to prevent tip damage.
