What is the content of the PCN (Personnel Certification in Non-Destructive Testing) Level 2 Penetrant examination?

TWI Frequently asked questions

by Ivan Pinson

The examination has both theoretical and practical sections.

1. Theory Examination

This consists of 2 multiple choice question papers.

• General

40 Questions (80 min)

Examples

1. The size of a penetrant indication depends on:-

   a. The size of the discontinuity
   b. The method of penetrant testing
   c. The flaw entrapment efficiency
   d. All of the above

   
   

2. In general, which of the following developers is the most sensitive?

   a. Dry
   b. Water suspended
   c. Solvent suspended
   d. Aqueous film

• Specific

36 Questions (72 min)

Examples

1. Which of the following defects is most likely to be missed due to improper post cleaning of a sample?

   a. Forging lap
   b. Fatigue crack
   c. Shallow and broad flaws
   d. Post cleaning does not affect the detection of defects

   
   

2. According to BS EN 571 the minimum level for UV-A lighting is

   a. 1000µW/cm ²
   b. 100µW/cm ²
   c. 500µW/cm ²
   d. 800µW/cm ²

   
   

3. Which of the following is not a casting defect?

   a. Cold shut
   b. Hot tear
   c. Porosity
   d. Lack of penetration

2. Practical

The 3 sections of the practical examination are:

• QA control check

Examples

Measuring the output of a UV-A lamp

Comparing the performance of 2 batches of penetrant chemicals

• Testing of 3 specimens in accordance with instructions provided and reporting the finding on proforma sheets provided.

  See figure 1.

  
  

• Producing a detailed instruction that a Level 1 technician could follow in order to test one of the components.

  The headings to be included are as shown in figure 2.

  Candidates must achieve a mark of over 70% on every section and a composite mark of over 80% (See ' How was my PCN mark calculated?').

For further information email the NDT Programme Manager

Fig. 1.

Please show defect dimensions and positions relative to a datum point and give a brief description of the defect type.

Fig. 2.

Marking Scheme for NDT Instructions

General Structure and Format (30 marks)

NDT Instruction reference (devised by the candidate)

Component identification

Originators name

Date of NDT instruction

Company name

Action to be taken on location of defects

Originators signature

Authorising signature

Operator Qualifications

Specific Instructions (70 marks)

Purpose of test

Equipment required

Preparation for test (equipment settings)

Safety precautions

Written instructions

Post test procedures (cleaning, protection, restoring finish)

Non-conformance statement

Total time: 1 hour