Publish Time: 2021-05-27 Origin: Site
When researching which digital weighing machine should be purchased for a specific business application, the two most common words are "legal for trade" and "NTEP approved". These two words are very important certifications for companies using digital weighing scale for trade. In all commercial uses where products are sold by weight, the scale required by law for trading is legal for trade. In addition, if the company needs to conduct business in the United States, then scales need to be approved by NTEP to be considered a legal transaction.
NTEP means National Type Evaluation Program. The National Type Assessment Program is implemented by the National Conference on Weights and Measures and the Weights and Measures Department of the National Institute of Standards and Technology. According to NTEP, the term "legal for trade" refers to any equipment used to sell, buy, process, exchange or determine the cost of a product on a weight basis.
The NTEP program is a rigorous testing process to evaluate whether the electronic weighing scale meets all existing government standards and requirements. Government standards are developed by NIST, and this standard is outlined in the NIST manual. The NIST standards in the manual cover all aspects of the NTEP, including capacity, accuracy and environmental factors, and even the way the brand name appears on the electronic weighing machine surface will affect the test results. The surface of the scale that has passed the NTEP test will have a NTEP certificate or a conformity number, so that it is convenient for local inspectors to obtain a copy of the certificate, and it is also convenient for the purchaser to confirm whether the platform weighing scale meets the NIST standard. But in addition to complying with the general NIST standards, when using the digital portable weighing scales, you also need to pay attention to whether it meets the standards and regulations of the region, because some regions have specific regulations.
The legality of scales is divided into four categories according to their accuracy to ensure traceability and accurate weighing. The weighing scale manufacturers will determine the accuracy level of the portable weighing machine according to the equipment structure design and the expected equipment application scenarios. The NIST manual includes specifications and tolerances for each accuracy class. But it is important to note that if any changes or repairs are made to any trade automatic weighing machine, it must be re-verified to ensure that it can still meet the approved requirements.
Class I Accuracy Standard
A scale that meets the Class I standard can be used as a reference standard for calibrating other weights, usually a high-precision analytical balance with a calibration readability as low as 0.1mg to 0.01mg.
Class II Accuracy Standard
The scale that meets the Class II standard is a calibrated high-precision top load balance with a readability as low as 0.01g to 0.001g.
Class III Accuracy Standard
Scales that meet Class III standards are medium-precision calibrated balances with readability as low as 0.1g to 0.01g.
Class IIII Accuracy Standards
A scale that meets the IIII standard is a calibrated semi-analytical balance for students.
In general, the legality of electronic weighing machines for shops used in trade is very necessary. In the United States, NTEP certification is very important for trade scales.