Abstract: An invented apparatus for nondestructively remotely measuring the health of an energetic material, includes a piezoelectric capacitance sensor having an exterior surface that is substantially inert to the energetic material. The piezoelectric capacitance sensor provides an analog signal that is commensurately responsive to the modulus of material in intimate contact with the sensor. The apparatus also includes an interrogator for interrogating the sensor as to a capacitance of the piezoelectric capacitance sensor. The interrogator converts the analog signal of the capacitance into a digital representation. The apparatus further includes a means of communicating the digital representation to a remote communication device.

Abstract: The invented method for measuring the health of a solid rocket propellant includes embedding at least one piezoelectric capacitance sensor in the propellant, where the capacitance of the sensor is a function of a modulus of the propellant, and where the position is selected to measure manifestations of stress failure as a consequence of changes in the shear modulus. The capacitance of the sensor is measured at a predetermined frequency. The capacitance of the piezoelectric capacitance sensor is converted into a digital representation which is then converted into the digital representation of a modulus (or gradient modulus). In subsequent analysis, the modulus (or gradient of the modulus) is correlated to the health of the solid rocket propellant.