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Manufacturer |
Bently Nevada |
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Product No. |
330851-01-000-050-10-01-00 |
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Product Type |
3300 XL 25 mm Proximity Probe |
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Probe Case Type Option |
02 = M30x2 Thread |
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Unthreaded Length Option |
000 = 0 mm |
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Armor Option |
01 = with SST Armor |
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Probe Tip Material |
Polyetheretherketone (PEEK) |
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Probe Case Material |
AISI 304 Stainless Steel (SST) |
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Operating & Storage Temperature |
-35°C to +200°C (-31°F to +392°F) |
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Weight |
0.330 Kg |
The 3300 XL 25 mm Transducer System consists of a separate 25 mm probe, an extension cable, and a 3300 XL 25 mm Proximitor® Sensor. The 0.787 V/mm (20 mV/mil) output provides a linear range of 12.7 mm (500 mils). This system is designed for measuring differential expansion (DE) in mid-size to large steam turbine generators, caused by differences in growth rates between the turbine rotor and the machine stator (casing).
Measuring Differential Expansion (DE)
The Differential Expansion measurement is performed using two proximity transducers observing a collar or ramp at a distance from the thrust bearing. Typical transducer mounting arrangements include:
Two transducers observing the same side of a collar.
Two complementary input transducers observing opposite sides of a collar, effectively doubling the measurable DE range.
Two transducers, with at least one observing a ramp on the rotor, while the second observes either a separate ramp or a different rotor location to compensate for radial movement. This method introduces some measurement error but allows for a longer total DE distance than the complementary measurement.
The mounting method selection depends on factors such as:
✔ Target size availability
✔ Expected rotor axial movement
✔ Type of DE target (collar vs. ramp)
If sufficient collar height is available, the preferred configuration is two transducers observing the same side of the collar, providing redundant measurements.
System Compatibility
The 3300 XL 25 mm probe is available in various case configurations, designed to replace all standard 7200 25 mm, 7200 35 mm, and 25 mm DE Integral transducer systems (including side and rear exit probes). The Proximitor Sensor output remains identical to the 7200 and 25 mm DE Integral systems, allowing customers to upgrade without modifying the monitor configuration.
⚠ Important: When upgrading from previous systems, all transducer system components (probe, extension cable, and Proximitor Sensor) must be replaced with 3300 XL 25 mm components to ensure proper functionality.
