Abstract: The invention relates to a process and an apparatus for defining the properties and composition of molding sand in casting works, wherein some of the properties are defined in a test sleeve which receives a molding sand sample. In order to create a process or a testing method which makes it possible to more quickly and easily determine the properties of the molding sand which are essential for purposeful use, the invention proposes to take an ultrasonic measurement of the sample of molding sand, wherein, independently of this, at least one further property of the sample of molding sand is measured or defined, and the combined results of the ultrasonic measurement and further measurement are used to define the properties and composition of the sample. In order to create an apparatus which makes it faster and simpler to define the properties of the molding sand which are important for purposeful application, at least one ultrasonic transducer is provided at an end of the sample.