Which characteristics are typically evaluated when selecting a penetrant for testing?

The selection of a penetrant for testing is critical to ensure effective non-destructive testing (NDT). The correct answer focuses on removal characteristics, flash point, and cost, which are key considerations.

Removal characteristics are important because they determine how easily the penetrant can be washed off after it has been applied and allowed to penetrate the test material. This affects both the cleanliness of the surface after testing and the reliability of the results, as any residue left could mask defects.

The flash point is another significant factor, especially in terms of safety and compliance with regulations during storage and application. A lower flash point may indicate a higher risk of fire and require special handling precautions.

Cost is always a factor in any testing procedure. It is essential to choose a penetrant that fits within the budget while still meeting technical and safety requirements.

Other characteristics such as the composition of the material, color, viscosity, application method, and storage criteria might be relevant as well, but the selection criteria that include removal characteristics, flash point, and cost are the standard evaluative aspects that directly impact the effectiveness and feasibility of penetrant testing. Thus, they form the core considerations when choosing an appropriate penetrant for testing.