When are dry magnetic particles typically preferred over wet magnetic particles?

Dry magnetic particles are typically preferred over wet magnetic particles during detailed inspections due to their ability to provide a higher level of sensitivity and detect surface and near-surface discontinuities more clearly. The use of dry particles allows for clearer visibility and better contrast against the test surface, which is essential when identifying smaller or more subtle defects that might otherwise go unnoticed.

Additionally, dry magnetic particles do not require a liquid carrier, which can sometimes obscure or wash away indications, especially in the presence of contaminants or during movement. This clarity is particularly important in applications where precision is critical, such as in aerospace and nuclear industries, where even minor defects could lead to significant failures.

While dry environments might suggest suitability for dry particles, environmental factors such as humidity are generally less influential on particle choice compared to the specific requirements of the inspection process. Thus, the preference for dry over wet particles ties directly to the need for high-detail inspections in diverse environmental conditions.