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platesEN 10160 quality class S2 – E3, and for castings EN 12680–1 severity level 3.

Testing techniques and scopecan be specified based on product quality and acceptance

level.

2.5. Testing procedure specified in written form

ASME, Sec. V and majority of European Standards (EN 12062: 2002 ′′Common rules

for non-destructive testing of metallic materials′′) request to present written procedure –

specified instruction for tested subject inspection by selected testing method. Instruction

should define testing techniques and parameters.

Program for the instruction composition for welded joints testing by x-ray, which

includes all the limitations, is available in EN 1435: 2003.

It might be requested to deliver the instruction for verification or to be presented to the

purchaser representative or authorised inspector.

2.6. Verification of testing parameters

Testing parameters have to be verified during procedure and proof the testing quality

before the decision of tested subject is made. For example:

• In ultrasonic testing, in addition to parameters cited in a part ′′Calibration of the

equipment′′ every four hours must be controlled distance range and sensitivity settings,

and in case of excessivedeviation all tests performed after last control must be repeated.

• In the magnetic particles inspection should be controlled: particles concentration in

the suspension,suspension susceptibility(using control block No. 1 or No. 2),-tangential

magnetic field capacity and/or magnetisation amperage,illumination of testing surface or

UV radiation and testing surface back illumination.

•In the x-ray testing it is to control: the level of backside radiation (lead number ′′B′′

on the cassette back side), film chemical procedure (using in advance exposed band), the

existence of requested marks on the radiograph,the existence of artefacts in considered

zones, radiograph darkness, and image quality value, and if some of these parameters

deviates of allowed value, the radiograph can’t be used for evaluation of tested subject.

2.7. Testing performance

Different testing levels might be applied according to required quality level of pro-

duct. For example, when testing welded joints:

• In x-ray tests two levels are defined, class A – base techniques, and class B –

advanced techniques. These classes differ in the value of minimal distance between

source and film, quality of used film and requested image quality value.

• In the ultrasonic tests four testing levels (A, B, C and D) are specified. The increased

probability of detection from level A to level C is achieved by increased covering that is

by scanning number (more scanning directions, more angles propagation, and surface

flattening). Testing level D is aimed for special applications.

2.8. Personnel in non-destructive testing

The greatest contribution in non-destructive testing is achieved by the request that

only personnelqualified and certified by corresponding standard can perform the testing.

In Europe it is EN 473: 2000 ′′Qualification and certification of NDT personnel′′

(harmonized standard of EC 23/97 directive).

Personnel in NDT are classified at three levels: