Product Introduction
The Bently Nevada 330172-00-20-05-02-CN is a precision 5mm proximity probe designed for non-contact vibration and position measurement in rotating machinery. Part of the 3300 series, this probe features a 1/4-28 UNF thread and includes armor for superior cable protection. Manufactured in the USA, it delivers consistent performance in demanding industrial environments.
Technical Specifications
The table below lists key parameters derived directly from the manufacturer's datasheet for the Bently Nevada 330172-00-20-05-02-CN.
| Parameter |
Value |
| Power Supply |
-17.5 Vdc to -26 Vdc at 12 mA max |
| Sensitivity |
Less than 2 mV/V change in input voltage |
| Output Resistance |
50 Ω |
| Probe DC Resistance (0.5 m length) |
7.45 Ω ± 0.50 |
| Probe Tip Material |
Polyphenylene sulfide (PPS) |
| Probe Case Material |
AISI 303 or 304 stainless steel |
| Probe Cable |
75 Ω triaxial, FEP insulated, 0.5 m length |
| Tensile Strength |
222 N (50 lbf) probe case to lead and lead to extension connectors |
| Connector Material |
Gold-plated brass or beryllium copper |
| Probe Case Torque |
5.1 N·m recommended, 7.3 N·m maximum |
| Connector-to-Connector Torque |
0.565 N·m maximum |
| Minimum Cable Bend Radius |
25.4 mm (1.0 in) |
| Probe Temperature Range |
-35°C to +177°C |
Application Use Cases and Failure Mode Prevention
In rotating machinery monitoring, proximity probes face common failure modes such as cable damage, tip wear, and magnetic field interference. The Bently Nevada 330172-00-20-05-02-CN addresses these with its armored cable and robust PPS tip. For example, in steam turbine vibration monitoring, the probe's high tensile strength (222 N) prevents lead-breakage under vibration. The probe's low sensitivity to 60 Hz magnetic fields (0.0014 mil pp/gauss at 50 mil gap) ensures accurate readings even near electrical machinery. To prevent premature pressure seal failure, avoid exposing the probe below -34°C.
Installation & Setup Guidance
Proper mounting is critical for accurate measurements. The Bently Nevada 330172-00-20-05-02-CN uses a 1/4-28 UNF thread with a maximum thread engagement of 0.375 inches. When drilling and tapping, use a #3 or larger tap drill. Apply a probe case torque of 5.1 N·m (45 in·lb); do not exceed 7.3 N·m (65 in·lb). For the ClickLoc connector, the maximum connector-to-connector torque is 0.565 N·m (0.42 ft·lbf). Ensure the cable bend radius does not drop below 25.4 mm to avoid internal damage.
Maintenance & Reliability
Routine inspection of the probe tip and cable is recommended. The probe operates reliably from -35°C to +177°C. To maintain pressure seal integrity, avoid operation below -34°C. The gold-plated connectors resist corrosion, and the stainless steel case provides durability in harsh environments. Following the specified torque limits prevents mechanical stress.
Selection Guide & Purchasing Advice
When selecting a replacement or upgrade, verify the probe length (0.5 m as configured here) and thread compatibility. This unit includes a miniature coaxial ClickLoc connector. For system integration, ensure your monitor supports -24 Vdc excitation and 50 Ω output resistance. PLC Source PRO offers this genuine Bently Nevada 330172-00-20-05-02-CN with full traceability. Check part number derivatives for different lengths or connectors.