A simple low‐cost circuit for automatic selection of two successive echoes during measurement of ultrasonic attenuation is described. When ultrasonic attenuation is measured as a function of a varying parameter like temperature, the transit time through the sample also changes, resulting in the shift of echo positions. This calls for manual adjustment of sample pulses used for sample and hold circuits. The present logic eliminates the need for manual adjustment. Details of the logic circuitry along with salient features of peak detectors and sample‐and‐hold circuits used are described. The results of performance tests are presented.