This NACE International standard test method provides descriptions of the measurement techniques and cautionary measures most commonly used on underground tanks to determine whether a specific criterion has been complied with at a test site. This standard includes only those measurement techniques that relate to the criteria or special conditions contained in NACE Standard RP0285. The measurement techniques described in this standard require that measurements be made in the field. Because these measurements are obtained under widely varying circumstances of field conditions and tank design, this standard is not as prescriptive as those NACE standard test methods that use laboratory measurements. Instead, this standard gives the user latitude to make testing decisions in the field based on the technical facts available.