Uncertainty Analysis Method and Process For Test Instrumentation System Measurements

摘要

Federal Aviation Administration (FAA) and Boeing product quality management policies dictate that test measurement calibrations be traceable to a primary standard, and test measurement uncertainties be known and documented. These uncertainties include instrumentation, signal conditioning, software, and test equipment used to collect the test data. The methods and processes to be used to determine and document uncertainties associated with over 20,000 test measurements supporting Boeing Commercial Airplane test programs are presented. Federal Aviation Administration (FAA) Evaluation Criteria 8100.7A and Federal Aviation Requirement (FAR) 21.39 require that all test equipment and test software be calibrated according to approved calibration procedures before the Type Inspection Authorization can be issued for any certification testing [1]. Boeing calibration procedures for test systems [2] call for all significant errors or uncertainties be evaluated and documented for each test measurement. The key topics, applicable to meeting these requirements, described in this paper include: (a) Configuration description of a "typical" complex test system, (b) Uncertainty determination methods and processes selected for end-to-end test system measurements, (c) Equations associated with test measurements and related parameters, (d) Identification of uncertainty contributors associated with test measurements and related parameters, (e) Determination of combined and expanded uncertainty estimates [7,8] for test measurements, and (f) A summary of end-to-end test measurement uncertainty methods and processes for a "typical" test system. These methods and processes have been used successfully to document test measurement uncertainties in order to comply with government and company requirements, and to ensure the consistently high quality of our products.