Phased Array Ultrasonics is an advanced method of ultrasonic testing that has applications in medical imaging and industrial non-destructive testing. Common applications are to non-invasively examine the heart of to find flaws in manufactured materials such as welds. Single element probes, known technically as monolithic probes, emit a beam in a fixed direction. To test or interrogate a large volume of material, a conventional probe must be physically scanned to sweep the beam through the area of interest. In contrast, the beam from a phased array probe can be focused and swept electronically without moving the probe. The beam is controllable because a phased array probe is made up of multiple small elements, each of which can be pulsed individually at a computer-calculated timing. The term, phased, refers to the timing, and the term, array, refers to the multiple elements. Phased Array Ultrasonic Testing is based on principles of wave physics, which also have applications in fields such as optics and electromagnetic antennae.