fallcone

Fallcone, or fall-cone test, is a simple laboratory or field method used to assess the consistency or viscosity of cohesive, semisolid materials such as clay pastes, slurries, or thick suspensions. The test relies on the gradual penetration of a standardized conical weight into a prepared sample under gravity. A metal cone with a specified mass and geometry is released from a fixed height or allowed to fall freely into the material, and either the penetration depth after a set time or the time required to reach a specified depth is recorded. The resulting measurement provides a comparative index of consistency or shear resistance.

Equipment and procedure are intentionally straightforward. The apparatus typically consists of a cone mounted on a rod or sleeve, a dish or mold to hold the sample, and a timing or depth-measurement device. The sample is prepared to a uniform consistency, the cone is released, and measurements are taken according to a standardized procedure. Temperature and sample preparation can influence results, so adherence to method details is important for repeatability.

Applications and interpretation vary by discipline. In soils and geotechnical engineering, the fall-cone test offers a quick, low-cost estimate of the consistency or shear strength of fine-grained soils and pastes. In food, cosmetics, and ceramics, it serves as a simple viscosity or thickening check. Results are semi-quantitative and most reliable when used with standardized cones and procedures, with comparisons made within the same testing framework.

Terminology varies; the device is sometimes called fall cone or fall-cone penetrometer, and procedures may be described as fall-cone testing or consistometry.