【国外标准】 Standard Practice for Performance Evaluation of the Portable X-Ray Fluorescence Spectrometer for the Measurement of Lead in Paint Films

5.1 The XRF instrument is used to measure the lead content in paint films in buildings and related structures in order to determine the potential lead hazard and the possible need for in-place control or abatement, or both.5.2 This practice also is to be used for the laboratory evaluation of the performance of portable X-ray fluorescence instrumentation.5.3 This practice is to be used as a guide for determining that the manufacturer of portable X-ray instrumentation has met certain requirements, most of which deal with instrument construction.5.4 The evaluation may be performed by the manufacturer, or an independent party. The results may be presented to various government agencies and, upon request, potential purchasers and users of the instrumentation. All or parts of this practice also may be performed by an X-ray instrument owner/user to determine the acceptability of an instrument or whether the performance of an instrument continues to be acceptable, or both.5.5 This practice may be used by field testers for quality control by performing selected activities described in the document on a regular and recurring basis in a manner similar to those protocols followed by users of laboratory instruments.5.6 Limitation—Bias and precision, as determined in the laboratory by this practice, together provide only an estimate of the accuracy that may be achieved in the field. Accuracy in the field will depend upon the instrument calibration, the form and composition of the substrate, the structure of the paint film being analyzed, as well as other factors.1.1 This practice covers portable X-ray fluorescence (XRF) instruments intended for the measurement of lead in paint. It is intended that manufacturers apply this practice to one unit of a particular model of an instrument when that model is initially available. Replicate tests on additional units of the same model of an instrument are to be performed at the discretion of the manufacturer. This practice also is intended for use by third parties performing independent evaluation of portable X-ray fluorescence instruments.1.2 All performance evaluation data are to be in SI units.1.3 Tests of performance are based on replicate measurements of certified reference paint films on a variety of substrate materials. Tests are performed to determine: bias, precision, linearity, limit of detection, interferences, substrate affects, and stability.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.