Rapid distance amplitude curve making method for ultrasonic testing instrument

The invention discloses a rapid distance amplitude curve making method for an ultrasonic testing instrument. The rapid distance amplitude curve making method comprises the following steps: Step 1: initializing: setting an initial value, and establishing a logarithm table which is used for quick switching between an amplitude value and a decibel value; Step 2: sampling multiple ultrasonic echoes at different positions, and reading and recording parameters of amplitude values, gain values and distance values; Step 3: normalizing: normalizing the recorded amplitude values and gain values, and obtaining a normalized decibel value; Step 4: generating a decibel curve: generating the decibel curve according to the normalized decibel value of each point by a fitting method; and Step 5: switching an amplitude curve: switching the decibel curve to the amplitude curve at a current gain by the logarithm table. The rapid distance amplitude curve making method provided by the invention generates the decibel curve by a fitt