In order to address issues that would affect confidence in the quality of the BASE data, a Quality Assurance Project Plan (PDF) - www.epa.gov/iaq/base/pdfs/qapp.pdf was developed in conjunction with the BASE protocol to ensure the collection of precise and accurate data and to provide guidelines that would allow the investigators to recognize and control factors that would compromise the data quality during the collection phase of the study.
During sample collection, duplicate samples run concurrently with a field sample, field blanks prepared like a sample but not run, and QC spikes were collected. In addition, sample verification procedures (i.e., sensor response comparison to known standards, comparisons to similar field instruments, etc.) were carried out to allow for assessment of data quality.
Upon completion of the field portion of the study, the precision and accuracy of the data was evaluated (see Available Measures of Precision and Accuracy Chart (PDF) - www.epa.gov/iaq/base/pdfs/precision_chart.pdf. A detailed discussion of the accuracy and precision of the data can be found in the report The Precision and Accuracy of Environmental Measurements for the BASE Program (PDF) - www.epa.gov/iaq/base/pdfs/precisionandaccuracy.pdf
Read more about the BASE Study at www.epa.gov/iaq/base