The non-destructive testing of a test object by way of ultrasound includes: (a) radiating directed ultrasonic pulses into the test object at an irradiation angle β wherein the irradiation angle β is set electronically, (b) recording echo signals that result from the ultrasonic pulses radiated into the test object, and (c) determining an irradiation position X0 in which echo signals can be recorded that can be associated with an error in the volume of the test object. The method also includes (d) determining the irradiation angle βmax for which the ERS value of the error reaches its maximum at position X0, (e) changing the irradiation position X0→X1 on the surface of the test object, the change of the irradiation position being captured, and (f) electronically adjusting the irradiation angle β in such a manner that the ERS value of the error reaches its maximum in the changed irradiation position X1.