AUT vs PAUT Hydroform

  • AUT vs PAUT Hydroform

    Posted by arsal on 27/11/2021 at 1:52 pm

    Dear All,

    We have performed (Raptor) AUT on Vessel shell (Nominal 22.50mm) and got one pin point location Around 17.35mm. Later we performed PAUT Hydro form (Omni scan MX2) in same location but didn’t get that pin point location where we got 17.35mm by AUT. In PAUT we got thickness around 22.50mm which is close to the nominal.

    My question-01: which data is reliable AUT or PAUT ?
    Question-02: By using which technic we can get the actual & reliable data ?

    Regards,

    lucas replied 5 months, 3 weeks ago 2 Members · 1 Reply
  • 1 Reply
  • Automated Pipeline Inspection (AUT)

    lucas

    Member
    27/11/2021 at 9:58 pm
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    It is possible to see a defect with conventional AUT (single or duel element transducers) and miss it with PAUT.

    Lets consider the differences in the two inspections:

    AUT: One transducer size, with flat focusing being most common.

    PAUT: Variable transducer size, with focusing.

    Now lets consider the following scenario:

    AUT: An inspection with a 6mm diameter Dual element transducer (14.13mm^2 active area) with no focusing is performed on a vessel with a nominal thickness of 22.5mm. The gain required to set the first backwall at reference may be quiet high, as this is a small transducer. This will make the chances of finding small inclusions, pin holes, and other small indications likely.

    PAUT: A 64 channel probe is used with an aperture size of 12 elements. At 1mm pitch, this creates a 12mm X 7mm probe (84mm^2) or 594% larger square area than the duel element 6mm diameter probe. The backwall of the part will give a much higher amplitude signal than a point indication, as the gain required for reference will be low. Add to this the extra variable of focusing (in or out of focus ) and it may be even more difficult to see a point indication.

    Please note that I am not saying that traditional AUT is more sensitive or more likely to find small indication. This is dependent on many variables and I beleive when PAUT is performed in optimal settings it has many advantages in comparison to traditional probes.

    To directly answer your questions:

    “My question-01: which data is reliable AUT or PAUT ?”

    [Levi]- It is not possible to answer this without knowing the parameters of your inspection.

    “Question-02: By using which technic we can get the actual & reliable data ?”

    [Levi]- Both techniques can give you accurate and reliable data.