This European Standard specifies ultrasonic acceptance levels, 2 and 3, for full penetration welded joints in ferritic steels, which correspond to the quality levels B and C of EN ISO 5817. Other acceptance levels can be used by specification. An acceptance level corresponding to level D of EN ISO 5817 has not been included in this standard as ultrasonic testing is generally not requested for this weld quality. These acceptance levels are applicable to testing carried out in accordance with EN 1714. The standard is applicable to the examination of full penetration ferritic steel welds, with thicknesses from 8 mm up to 100 mm. It can also be used for other types of welds, materials and thicknesses above 100 mm, provided the examinations have been performed with necessary consideration of the geometry and acoustical properties of the component and an adequate sensitivity can be employed to enable the acceptance levels of this standard to be applied. The nominal frequency of probes used in this European Standard is between 2 MHz and 5 MHz unless attenuation or requirements for higher resolution call for another frequency. The use of these acceptance levels in conjunction with frequencies outside this range needs to be considered carefully.