One of the non - destructive tests is “liquid penetrate testing”. In this type a liquid penetrant is passed through the object to be tested.

Which one of the following is a disadvantage in the above test?

Liquid Penetrant Testing:

• A liquid penetrant dye is passed through the object to be inspected
• By capillary action, the liquid seeps into the defects in the material
• A developer is applied to the material which pulls back the penetrant and forms an indication on the surface of the material, which is much easier to see than the crack itself
• This non - destructive testing technique can be used to find the cracks, pores and other surface defects

Advantages

• Parts with large surface areas can be measured rapidly at a low cost
• Low initial investment cost
• Parts with complex shapes can be inspected

Disadvantages

• Can be applied only on nonporous materials
• Chemicals used could be toxic, and so precautions need to be taken
• Cleaning necessary before and after the material is tested by this technique