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Cable Extension Transducers Cale Ash CEE 398KUC

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Page 1: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Cable Extension Transducers

Cale Ash

CEE 398KUC

Page 2: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Measurement Problem

Need to measure linear distances/displacements:

LVDT CETLinear Variable Differential Transformers Cable Extension Transducers

Two Options:

RangeUp To 12 in.

~$600 (12in.)

Flexible cable, but has

more moving parts

Rod can bend, but

fewer moving parts

~$400 (60in.)

Up To 1700 in.

Cost

Durability

Page 3: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Types

Cable Extension Transducers (CETs) Come In:

•Industrial Grade

•Laboratory Grade (Discussed here)

As well as in various sizes:

1.5” 3.5” 12”

Page 4: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Applications

Cable Extension Transducers (CET):

•Measure Linear Position

•Indicate Velocity and Acceleration

•Provide Reliability and Serviceability

• >105 cycle life

•Cable user-serviceable

Page 5: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Superior Performance

CETs are ideal in many instances:

•Where Perfect Alignment is Not Possible

•Cannot use LVDT Here!

•Where Large Displacements are Expected

•Up to 100” for Laboratory Models

•Up to 1750” (145ft.!) for Industrial Models

Page 6: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Superior Performance

CETs are ideal in many instances (cont.):

•If Difficult Mounting Conditions are Encountered

•Pulleys Enable Additional Flexibility

•Rigid Support Far From Measuring Point

Page 7: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Technology

Cable is wound around a precision machined spool attached to either a:

•Potentiometer (variable resistor, analog)

•Incremental Encoder (optical, digital)

A spring provides controlled recoil of the cable.

X-Ray Vision!

Page 8: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Instrumentation

Measurement Options Include:

Voltage

Divider

Unregulated

Input

Incremental

Encoder

Current

Output

NSEL Models

Page 9: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Models Used In NSEL

Both models feature:

•Adjustable Zero & Voltage Output

•High Accuracy (+/- 0.25%)

•Multiple Extension Ranges:

•PT1DC 0-2in. to 0-50in.

•PT510 0-2in. to 0-100in.

PT510

PT1DC

Page 10: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Availability

LVDT CET

Page 11: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

Summary

•CETs provide a useful, sometimes superior, alternative to LVDTs.

•Rotary potentiometer provides long life and simple output

•CETs are also cost effective and easy to install

Page 12: Cable Extension Transducers Cale Ash CEE 398KUC. Measurement Problem Need to measure linear distances/displacements: LVDTCET Linear Variable Differential

References

www.celesco.com CET Manufacturer

http://cee.ce.uiuc.edu/nsel/Facility/

For instrument availability