Laboratory accreditation is a formal process that recognizes the technical competence of a laboratory to perform specific tests or calibrations. Accreditation requires laboratories to maintain a documented quality management system (QMS) and personnel who are qualified and authorized to perform tasks related to the scope of accreditation. The added value of accreditation far outweighs the necessary investment in human resources, finances and time, since it is an independent method of monitoring laboratory competence and performance, and assures the validity of results disseminated to users. One very critical benefit of laboratory accreditation is that it provides assurance to trading partners that an exporting country is competent to test or inspect to the trading partners’ requirements, while at the same time addressing and assuring compliance with the World Trade Organization's (WTO) Technical Barriers to Trade (TBT) Agreement. Calibration is the process of comparing a measuring instrument against a measurement standard to establish the relationship between the values indicated by the instrument and those of the standard (standard in measurement is considered to be the reference base). The purpose of calibration is to eliminate or reduce bias in your measurement system relative to the reference base. The calibration procedure compares an "unknown" or test item(s) or instrument with reference standards according to a specific algorithm.