The Bently Nevada 3300 XL 50mm Proximity Transducer System includes a 50 mm probe, extension cable, and Proximitor sensor. With its large coil design, this system offers an extended linear range of 27.9 mm (1100 mils), the longest available in its product line. This makes it ideally suited for measuring differential expansion (DE) or rotor expansion (RX) in large steam turbines.

The 3300 XL 50mm system measures differential expansion using two probes that monitor a collar or ramp surface. The extended measurement range provides flexibility for various mounting configurations:

• Two probes can monitor the same side of a collar for redundant measurements
• Probes can be positioned on opposite sides of a collar to double the total measurement range

The optimal mounting configuration depends on target size and rotor movement range:

• For collars of sufficient size with movement less than 27.9 mm, dual probes on the same side provide backup measurement capability
• For movement ranges between 28 mm and 56 mm, probes must be mounted on opposite sides of the collar