3.5 Daily calibration -- A calibration performed with minimal standards to ensure that the primary calibration is valid. For example, when two standards within the range of interest are analyzed and agree within 10% of their true value the primary calibration is assumed to be valid.
3.6 Memory effects -- Mercury vapor may remain in the decomposition tube, amalgamator, or absorbance cells and be released in a subsequent analysis resulting in a positive bias. For example, this may result when a low concentration sample is analyzed after a sample of high mercury content.
3.7 Sample boat -- The non-amalgamating thermally stable vessel used for containment and transport of the solid or liquid sample for thermal decomposition.
3.8 Also refer to Chapter One, Chapter Three, and the manufacturer's instructions for definitions that may be relevant to this procedure.