Traceability of measurements
The term traceability is described in the
International Vocabulary of Basic and General Terms in Metrology as follows.
“Characteristic of a reference value or
measurement result in which all uncertainties are clearly described and can be linked to an unambiguous
standard (national or international standard) through a link continuous comparison.”
Therefore, when demonstrating traceability for VILAS certification,
calibration laboratories must not only support an unbroken link between comparisons with national standards,
but also inherent uncertainty, the assurance of proper measurement, calibration and handling procedures..
Why measurement traceability is required?
Measurement is the basis for the production of goods and services, and national metrological standards are the basis for industrial and social organizations. Weighing standards are the basis for manufacturing, testing and testing processes, product testing, health and safety, environmental monitoring, food processing, application of new technologies, scientific progress and fair trade in the domestic economy.
Measurements are all around us, and although they are important, they are often overlooked. In addition, because testing is measurement-based, mutual acceptance of measurement and measurement traceability are the most essential prerequisites for mutual recognition of test results. Now, there is growing international awareness of the importance in quality control, and the introduction of a quality control system such as ISO9000 is widespread. However, it is clear that the quality control system itself does not create quality. The quality control system is a mechanism for monitoring the process and ensuring consistency, not a guaranteed product quality. In fact, the quality control system can also be a means of continually creating defective products if the measurement or measurement process involved in the manufacturing or testing process is incorrect.
Whether it is used for raw material inspection, process control or finished product inspection, assurance requirements for quality assessment or measurement results involve two aspects: competence and traceability of the origin of the measurements. Competence at this time concerns metrology personnel, measurement methods and quality systems, and is best demonstrated through third-party accreditation according to ISO/IEC 17025.
Determining the origin of the measurement is also related to the accuracy of the measuring device. It must be purified in the physical unit in which the measurement is provided by the measuring instrument or instrument being measured and ultimately requires traceability to the measurement standard through the underlying perception of the unit. This is because the demand for international approval for product testing and conformity in the global market is increasing everyday, and so there is a need for traceability with international measurement standards.
For accurate measurements
The international standard of measurement for SI units is the basic standard maintained by the International Bureau of Weights and Measures (BIPM) and the international comparison program, in particular the national system of measurement which is proven to correspond to other basic standards through the program (Main Comparison) chaired by the International Bureau of Weights and Measures. It includes standards maintained by the laboratory. The main task of national metrology laboratories internationally is to establish basic standards and to prove their accuracy through international comparisons.
As SI units are realized, there is growing international interest in the fact that fundamental standards tend to be very specific single value standards and traceability alone has been established. Proofs against such criteria are not sufficient to demonstrate their ability over a sizable range of numbers or values which is becoming.
For this reason, the pressure on the National Metrology Institute to engage in a series of international comparisons to more efficiently represent capacity and traceability is increasing.
For example, traceability evidence through international comparison of the basic 1Ω standard in the field of resistors does not demonstrate the ability to measure very large resistance values that require slightly different techniques. This question has been raised by the International Bureau of Weights and Measures and its Advisory Committees.
In short, measurement is essential to establish the foundation of testing, conformity assessment and international trade, which are essential elements of national economic development. In addition, mutual recognition of national metrological standards and the capabilities of national metrology institutes is an essential condition for maintaining the traceability of international metrological standards.
