ultrasonic - oxide scale procedure

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GE Inspection Technologies Ultrasonics

Application

ar ox e coat ng w gra ua y u

p on the inside of power generation

boiler tubes. The thicker the oxide layer,

t e ess e cent t e o er ecomes an

additional heat build up will shorten thelife of the boiler.

Boiler tube oxide/scale thickness

measurement

Application Solutions 70024ELDate: August 2004

Industry Segment

nergy

ater a

Steel

Your solution

The object of the test is to perform a sepa-

rate thickness measurement of the steel

tube wall and the oxide scale layer located

on the ID of the tube.

The interface echo from the tube-to-oxide

is much smaller than the echo from the

oxide-to-air interface, thus, the difficulty

is separating these two echoes from eachother and making the measurement be-

tween the two echoes.

How you benefit

Measure Thinner Oxide/Scale Layers

Measure Oxide on Thick Wall Boiler

Tubes Save A-Scan and instrument

parameters in Data Sets

Use compare mode to view set-up

standard against actual measurement

High display resolution and range

allows for clear signal interpretation

and resolving the measurement

What you need

SN-58L or USN-60

IF Gate option (for either unit)

Shear Wave DFR Probe 291-484-

700

BNC-MD or Lemo-MD cable

SLC-70 couplant

The example above shows the steel to

oxide interface echo at about 1/3 the am-

plitude of the oxide to air interface echo.

sing a highly damped Alpha type

traight beam Shear Wave probe is the

ey to obtaining thin oxide layer mea-

urements. The shear waves have the

elocity of L-waves which doubles the time

esolution and enables the sy em to mea-

ure thinner layers than with conventional

-wave probes.

ote: loose scale measurement is not

oss e

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GE Inspection Technologies Ultrasonics

2004 General Electric Company. All rights reserved GEIT7 024EL (08/04)

We reserve the right to technical modifications without prior notice

The USN set up requires a simple set-up

to make two thickness measurements.

Set te USN t t e mmers on mo e

Set the water path velocity to thevelocity of steel, shear wave

Set the main velocity to the velocity of

the oxide

Set gates to flank detectionGate settings (echoes):1st gate to inner surface of tube2nd gate to inner surface of oxide

Contact our global Application Centers for solutions to your inspection problems

20 MHz crystal size.

Special Y-Cut ceramic produces Shear wave and an excellent Alpha waveform

Replaceable delay lines for easy change out.

Shear waves are being used for the thickness measurements thus an attenuative cou-

plant is needed. SCL-70 couplant provides the best shear wave transmittion into the

boiler tube.

European Center

Cologne, Germany

Dr. Werner Roye

werner.roye@ae.ge.com

+49-2233-601-529

European X-ray Center

Ahrensburg, Germany

Dr. Matthias Purschke

Matthias.purschke@ae.ge.com

+49-4102-807-458

European Eddy CurrentCenter

St Albans, England

ukec.app@ae.ge.com

+44-1727-795555

North American Center

Lewistown, PA

Don Henry

don.henry@ae.ge.com

+1-717-242-0327

North American X-ray Center

Cincinnati, OH

Tammie Johnson

tammie.johnson@ae.ge.com

+1-513-552-4685

Oil/Petrochemical Center

Houston, TX

Opening Fall 2004

China Center

Shanghai, China

Robert Lee

robert.li@ae.ge.com

+86-21-5050-4666 ext. 1275

France Center

Limonest, France

Michel Hervier

michel.hervier@ae.ge.com

+33-47-217-9220

United Kingdom Center

Coventry, England

Dr. Sue Oaten

sue.oaten@ae.ge.com

+44-2476-47-2568

orldwide Film Center

erchem, Belgium

ris Marstboom

ris.marstboom@ae.ge.com

+332-444-8263