Technical barrier to trade (TBT) has become one of the significant non-tariff measures with the advent of the WTO system in 1995. The key issue in TBT is that technical regulations, standards, and conformity assessment should not be used as barriers to trade. Regarding conformity assessment, the WTO/TBT Agreement recommends members to enter into negotiations for the mutual recognition of results of each other's conformity assessment, as well as to permit participation of conformity assessment bodies located in other members. In this paper, it will be reviewed why the role of measurement science is important in terms of international effort to eliminate technical barriers to trade particularly in the area of conformity assessment.

In the laboratory of Hydraulics and Hydraulic Construction of the Faculty of Engineering of L'Aquila, a physical model was made for the study of steady-state, gradually varied motion flow in open channel networks. For this study, a calculus algorithm has been used proposed by [1] which gives, in the case of slow water flow into gradually declined channels, in the direction of motion, the volumes and water levels respectively, in all the nodes and sides of the network.

Generally, the determination of the performance and quality of volumetric flow meters is being carried out using so called error curves. They are the result of experiments performed on test rigs for different design variations and operating conditions. In order to augment this development process for flow meter to reduce costs in terms of money and time, computational fluid dynamics (CFD) software has been applied as the so called "Numerical Test Rig". This "Numerical Test Rig" includes a full three-dimensional flow simulation of a realistic meter configuration. Close attention was paid to correct reproduction of the meter features, requiring simulation of the complete geometry with flow straightener, rotor and the downstream domain, all within a 360° circumference. A new algorithm to determine the error curves was developed based on the detailed consideration of inflow and outflow velocities. Equally, the realistic computation of the bearing friction forces and moments was implemented. Simulations of several test cases produced resulting error curves that compared favourably with curves measured for real meters.

Vacuum technology is one of the established advanced technologies, of present age, in the field of research and industry. Having numerous applications, in the areas of human activities, one is concerned with a relatively large vacuum chamber where pressure distribution is, usually, not uniform during dynamic gas flow. To minimize the pressure non-uniformities in such chambers, baffles are generally used. In the present work, rectangular-shaped baffles of different sizes are used in a cylindrical-shaped chamber of a flow-control system, developed by Korea Research Institute of Standards and Science (KRISS). The chamber is large enough and has been experimented for pressure distribution at four different points in the pressure range from 0.1 Pa to 133 Pa by using five identical Capacitance Diaphragm Gauges (CDGs). One of these gauges serves as a reference gauge and is fixed at one point while the readings of the other four gauges were recorded by using baffles of various sizes and, at the same time, producing the pressure dynamically in the chamber. It is worth mentioning that before installation, all of these gauges were calibrated on Ultrasonic Interferometer Manometer (UIM). The data, thus obtained, along with relative deviations of the gauges’ readings are plotted for all the three baffles which represent the behavior of gas pressure in this particular chamber.

The growing attention is paid to food analysis area in recent years. National Metrology Institutes have been playing the important roles in obtaining reliable, comparable and traceable analytical data. In this paper, the tasks and performances of National Institute of Metrology (NIM) China in the National System of Metrology in Chemistry (NSMiC) for food analysis are reviewed in the following aspects including: establishing the national primary standards, developing CRMs, organizing national proficiency tests, participating in CCQM comparisons and claiming Calibration Measurement Capabilities (CMCs). Finally, future perspective for the metrological underpinning to the development of food analysis is overviewed.