Product details

Origin:USA

Brand:bently

Product ID:330851-04-000-030-10-00-05

product description 

3300 XL 25mm Proximity Transducer System

Description

The 3300 XL 25 mm Transducer System consists of a separate25 mm probe, an extension 

cable, and a 3300 XL 25 mmProximitor Sensor.  The 0.787 V/mm (20 mV/mil) output givesthis 

system a linear range of 12.7 mm (500 mils).  Based on thislinear range, the 3300 XL 25 mm 

Transducer System is suitablefor measuring differential expansion (DE) on mid-size to 

largesteam turbine generators caused by the difference in growthrates between the turbine 

rotor and the machine stator(casing). 

Measuring Differential Expansion (DE)

The Differential Expansion measurement is made by twoproximity transducers observing a collar 

or ramp somedistance from the thrust bearing.  Typical transducer mountingarrangements are:

l Two transducers observing the same side of a collar.

l Two complementary input transducers observing opposite sides of a collar, effectively doubling 

the measurable DE range.

Two transducers with at least one transducer viewing a rampon a rotor and the second transducer 

viewing either a separateramp or a different location on the rotor to compensate forradial movement.  

This arrangement adds some error to themeasurement, but can measure a longer total DE distance 

thanthe complementary measurement.

The criteria for selecting a mounting method are the size ofthe available target, the expected amount 

of rotor axialmovement and the type of DE target that exists in the machine(collar versus ramp).  

If sufficient collar height is available, twotransducers observing the same side of a collar is thepreferred 

configuration.  These two transducers provideredundant measurements.