klopftest

Klopftest, literally “knock test” in German, is a term used in several disciplines to describe a simple tapping- or percussion-based evaluation. The underlying principle is to elicit acoustic or tactile feedback from an object or body by tapping with a finger, hammer, or specialized probe, and to interpret the resulting sound or sensation to infer properties such as structure, density, or pathology.

In medicine, percussion tests are part of the physical examination. A clinician taps on a body surface (for example the chest or abdomen) to assess underlying organs or compartments, with the aim of identifying abnormalities such as fluid, air, or solid masses. In dentistry, a percussion test is used to evaluate tooth vitality: tapping a tooth can provoke pain if the dental pulp is inflamed or compromised, helping guide diagnosis and treatment planning.

In materials science and engineering, knock tests or tap tests are quick, non-destructive methods to screen for defects or inconsistencies. By listening to the produced tone or feeling the response, testers can identify delaminations, voids, cracks, or poor bonding in materials such as ceramics, composites, plastics, wood, or metal components. The method is typically qualitative and used as a preliminary screening before more precise nondestructive testing or imaging.

Limitations and scope vary by field; klopftests are generally considered rapid, inexpensive, and non-invasive but are not substitutes for rigorous diagnostic or testing techniques. Proper technique and interpretation depend on established procedures within each discipline.