Résumé
The ultrasonic sensor is composed of a resonator excited by a piezoelectric element. It is in the shape of a solid metallic cylinder with a fine cylindrical tip. The tip is dived into the cement to be tested, where it generates propagating and standing waves. The frequency of resonance of the system gives us information on the elastic properties of the paste. The sensor is mostly sensitive to the shear modulus G' of the medium. With the described sensor, the range 106 < G' < 107 Pa is tested. Other ranges can be selected by changing the size of the cylinder or the tip.