330191-00-08-90-05 Bently Nevada 3300 XL 8 mm ETR Probe, 9.0 m

What Makes the 330191-00-08-90-05 the Right Choice for Critical Machinery?

How can you achieve reliable, non-contact displacement measurement in extreme industrial environments? The Bently Nevada 330191-00-08-90-05 proximity probe answers that challenge with engineering-grade precision. As part of the 3300 XL series, this 8 mm eddy current transducer (ETR) probe provides exact, isolated measurement of shaft vibration and axial position. Its 3/8-24 UNF thread and 9.0-meter total length suit installations where the probe must reach deep into a machine casing. Moreover, the absence of armor reduces weight and diameter for tight routing. Every specification reflects meticulous design for long-term reliability.

Key Specifications of the 330191-00-08-90-05 Probe

• Input Voltage: Requires -17.5 Vdc to -26 Vdc when installed with a nonincendive circuit per drawing 140979.
• Current Consumption: 12 mA maximum; -23 Vdc to -26 Vdc with barriers.
• Output Resistance: 50 Ω nominal.
• Nominal Probe DC Resistance: 9.87 ± 0.50 Ω from center to outer conductor.
• Isolation: Differential pressure sealing between probe tip and case via Viton® O-ring.
• Probe Tip Material: Polyphenylene sulfide (PPS) for rugged encapsulation.
• Case Material: AISI 303 or 304 stainless steel.
• Cable Type: 75 Ω triaxial, FEP insulated (standard) or PFA insulated (extended temperature range).
• Tensile Strength: 330 N (75 lbf) probe case to lead; 270 N (60 lbf) at lead to extension cable connectors.
• Connector Material: Gold-plated brass or gold-plated beryllium copper.
• Maximum Connector Torque: 0.565 N•m (5 in•lbf).
• Thread Engagement: 3/8-24 UNF, maximum 0.563 in.
• Weight: 323 g/m (11.4 oz).
• Agency Approvals: CSA, ATEX, IECEx (option 05).

For specifications not listed, refer to the official Bently Nevada datasheet.

Applications and Use Cases for the 330191-00-08-90-05

This probe excels in turbomachinery monitoring where precise displacement data is critical. For instance, in steam turbine axial position measurement, the 9.0-meter length allows the probe to be mounted in a remote location while still reaching the thrust collar. Additionally, the ETR (Extended Temperature Range) cable option ensures reliable operation in high-temperature zones up to +232°C (T1 classification). Furthermore, the absence of armor makes it ideal for applications where cable flexibility and minimal weight are paramount. Consequently, you can use it in compressors, gearboxes, and large motors. The isolated measurement principle eliminates ground loops, ensuring signal integrity.

Installation and Maintenance Guidance

Proper installation begins with verifying the probe's input voltage. The 330191-00-08-90-05 requires -17.5 Vdc to -26 Vdc when used with a nonincendive circuit. Operation at a more positive voltage than -23.5 Vdc can reduce linear range. Therefore, always confirm your power supply meets these exact requirements. Mount the probe using the 3/8-24 UNF thread, ensuring maximum engagement of 0.563 in. Use a torque wrench to tighten the connector to 0.565 N•m (5 in•lbf) to avoid damage. For maintenance, inspect the probe tip periodically for wear or contamination. Since the probe seals differential pressure with a Viton® O-ring, check for leaks if the machine experiences pressure fluctuations. However, do not disassemble the probe; it is not pressure tested prior to shipment. Instead, follow the manufacturer's safety manual for any service.