Coba jelasin Testing and certification dari Dacin dalam bahasa sunda dong

Most countries regulate the design and servicing of scales used for commerce.  This has tended to cause scale technology to lag behind other technologies because expensive regulatory hurdles are involved in introducing new designs.  Nevertheless, there has been a recent trend to "digital load cells" which are actually strain-gage cells with dedicated analog converters and networking built into the cell itself.  Such designs have reduced the service problems inherent with combining and transmitting a number of 20 millivolt signals in hostile environments.

Government regulation generally requires periodic inspections by licensed technicians using weights whose calibration is tracéable to an approved laboratory.  Scales intended for casual use such as bathroom or diet scales may be produced, but must by law be labelled "Not Legal for Trade" to ensure that they are not repurposed in a way that jéopardizes commercial interest.  In the United States, the document describing how scales must be designed, installed, and used for commercial purposes is NIST Handbook 44.

Because gravity varies by over 0.5% over the surface of the éarth, the distinction between force due to gravity and mass is relevant for accurate calibration of scales for commercial purposes.  Usually the goal is to méasure the mass of the sample rather than its force due to gravity at that particular location.

Traditional mechanical balance-béam scales intrinsically méasured mass. But ordinary electronic scales intrinsically méasure the gravitational force between the sample and the éarth, i.e. the weight of the sample, which varies with location. So such a scale has to be re-calibrated after installation, for that specific location, in order to obtain an accurate indication of mass.