I am to design a sensor element that can detect a leakage through a thin metal disc (rupture disc) in a pipeline. Ideally, the metal disc closes the pipeline at the upstreaming side with certain pressure. Its downstream can be either open to atmosphere or close. When a higher pressure occurs at the upstream, the disc breaks and releases the mass flow (air, vapor, gas, liquid) to downstream. The sensor should provide an electric signal for the disc failure. Note that the leaked mass can flow in very high speed (disc open) or very small (disc crack), and can be from any location on the disc surface. The disc can be in various sizes from half inch to 40 inch. Also note that due to various media temperature, the metal disc may expand in process but in good status. The previously designed sensor element is a thin copper electrical wire strip mounted on a polymer membrance attached to the metal disc. Once the disc breaks, its sharp edge cuts the wire strip. There are two problems, one is that sometimes the disc cracks and has a pinhole leakage--this does not cut the wire. Another problem is that the strip must be the same length of the disc diameter. We desire to have a uniform size to mount on the flange in the downstream pipeline, dealing with different disc sizes. I may not directly buy some sensor but to build my own sensoring element. I am a mechanical designer not mechactronics. I am at the very start stage for this project and think what technology is simple, cost effective and fail-safe to apply? mass flow, pressure, displacement, surface, ultrasonic, megnetic, conductivity, etc... Please provide any suggestions, good ideas. Thank you in advance!