This document specifies methods and acceptance criteria within the frequency range of 0,5 MHz to 15 MHz, for assessing the performance of equipment dedicated for determining thickness using pulse-echo ultrasound, e.g. according to ISO 16809. This document covers verifications needed for the determination of thickness, only. This document covers both instruments with numerical display and instruments with A-scan presentation using either single- or dual-transducer probes. This document can be used for verifying equipment covered by ISO 22232-1 and ISO 22232-2 when used for thickness determination.