SNR or S/N

Signal-to-Noise Ratio 

SNR or S/NSignal-to-Noise Ratio is the ratio of the amplitude of a signal of interest relative to the amplitude of noise signals. The signal-to-noise ratio shows how clearly a signal can be distinguished from the noise: the higher the SNR, the more reliable the detection of the defect indication will be.

SNR can be measured in many NDT techniques. In ultrasonics, it is the amplitude of a signal generated by a defect divided by the amplitude of the surrounding background noise and expressed in dB. In this case, the noise can be the electronic noise of the instrument or it can be ultrasonic signals scattered by the structure of the material.

For more information on SNR in ultrasonics see:

More information on SNR in radiography can be found in:

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