Methods of performing ultrasonic testing are disclosed, comprising the step of determining a temperature gradient of an ultrasonic wedge. In one embodiment of the invention, the method further comprises the steps of determining a sound velocity gradient of the ultrasonic wedge to determine the time it takes for sound waves emanating from a plurality of ultrasonic transducer elements attached to the ultrasonic wedge to reach a point of interest within a test object, and firing each of the ultrasonic transducer elements in a timed sequence based on the times such that sound waves from each of the ultrasonic transducer elements reach the point of interest at the same time. In other embodiments of the invention, the total attenuation and acoustic impedance of a sound wave traveling through the ultrasonic wedge is determined to adjust the amplitude of the sound wave such that the sound wave has sufficient amplitude to perform the ultrasonic testing.