Abstract: A method and an apparatus for consolidating concrete test samples include a tubular tamping rod with a reference disc slidably mounted thereon. When performing a quality control test, a worker pours a concrete specimen into a test container. The tamping rod is positioned adjacent to the container with its lower end at a maximum acceptable submersion depth relative to the specimen. The reference disc is then positioned to engage the upper edge of the container when the lower end of the rod is at the maximum acceptable submersion depth. When the worker reciprocates the tamping rod within the specimen, engagement of the reference disc with the upper edge of the container indicates that the lower end of the rod has reached the maximum acceptable submersion depth.