APPARATUS AND METHOD FOR MEASURING PHYSICAL CHARACTERISTICS OF MATERIALS

摘要

An instrument and a method are provided for determining the moisture and cement contents of fresh concrete and for calculating and displaying to the user of the instrument the projected strength of the concrete. The instrument has two probes, each probe containing a low-activity nuclear source. The probes are stored in shielded receptacles in a housing when not in use. The user calibrates the probes with reference to concrete compositions of known cement and water content, and then for field use separately inserts each probe into the access tube of a sample pan filled with concrete to obtain counts corresponding to moisture content and cement content. An electronics unit is attached to the housing for storing the correlations and performing the calculations.