ultraheliimpulsside peegeldumisel (vastukajamisel) põhinev mittepurustav katse (vt ultraheliimpulss-kajadefektoskoopia), non-destructive pulse-echo test, in which a short pulses of ultrasonic energy are introduced into a testpiece at regular intervals of time while some or all of the energy is reflected; the proportion of reflected energy is dependent on the size of the reflecting surfaces (flaws) (see: ultrasonic pulse-echo defectoscopy)