Quality Assurance Procedures
The quality assurance and quality control (QA/QC) program pertaining to the instrument calibration has previously been discussed. However, it should be noted that the proton beam energy is stable to better than 1 part per 1000, and the beam density profile uniform to better than 0.5%. This assures a uniform and constant X-ray production from the target sample. As a further guarantee of machine stability, a quality control standard can be run at the client’s discretion, not to exceed once per hour. In addition, replicate analyses can be performed upon the client’s request. It is suggested that the client provide blanks (as well as field blanks) for aerosol filter analyses and for analyses which require a blank subtraction to be performed. EAI will, again, leave the total number of blanks to be run to the discretion of the client.
EAI also maintains and extensive library of standards from NBS, NIST, USGS, NIES and acquisitions from individual clients which can be used for QA/QC upon the client’s request. These standards have all been previously analyzed by other approved techniques and their values are either certified or well established.