ISO/IEC Guide 98-4:2012

ISO/IEC Guide 98-4:2012 provides guidance and procedures for assessing the conformity of an item (entity, object or system) with specified requirements. The item might be, for example, a gauge block, a grocery scale or a blood sample. The procedures can be applied where the following conditions exist: the item is distinguished by a single scalar quantity (a measurable property) defined to a level of detail sufficient to be reasonably represented by an essentially unique true value; an interval of permissible values of the property is specified by one or two tolerance limits; the property can be measured and the measurement result expressed in a manner consistent with the principles of the GUM, so that knowledge of the value of the property can be reasonably described by (a) a probability density function, (b) a distribution function, (c) numerical approximations to such functions, or (d) a best estimate, together with a coverage interval and an associated coverage probability.