Manufacturer : Bently NevadaProduct No. : 330850-91-CN
Product type : 3300 XL 25 mm Proximitor Sensor
Total Length and Mounting Option : 91 = 9.0 metres (29.5 feet) system length, DIN mount
Agency Approval Option : CN = Approvals country specific (CN Approvals Option Quick Reference Guide and Field Notification Letter are in the download section)
Weight : 0.323 Kg
The 3300 XL 25 mm Transducer System consists of three key components:
A separate 25 mm probe
An extension cable
A 3300 XL 25 mm Proximitor® Sensor
With an output of 0.787 V/mm (20 mV/mil), this system provides a linear range of 12.7 mm (500 mils). Due to this linear range, the 3300 XL 25 mm Transducer System is ideal for measuring Differential Expansion (DE) in mid-size to large steam turbine generators, which experience expansion differences between the turbine rotor and the machine stator (casing).
Measuring Differential Expansion (DE)
The Differential Expansion (DE) measurement is conducted using two proximity transducers that monitor a collar or ramp located a certain distance from the thrust bearing.
Common transducer mounting arrangements:
Same-Side Collar Observation
Two transducers observe the same side of a collar.
Complementary Input Transducers
Two transducers observe opposite sides of a collar.
This effectively doubles the measurable DE range.
Rotor Ramp Observation
One transducer monitors a ramp on the rotor.
The second transducer monitors either a separate ramp or a different location on the rotor to compensate for radial movement.
While this setup introduces some measurement error, it allows for a longer total DE measurement range compared to the complementary method.
