EN
According to the verification requirements, the indicators such as indication error, load error, repeatability, and discrimination ability of the electronic weighing scale were verified under laboratory conditions.
Indication error refers to the difference between the indication of the electronic scale and the mass-agreed true value. During verification, the tested load points must include zero load, minimum scale amount, load corresponding to the conversion point of maximum allowable error, maximum scale load, etc. The load should start from zero load, gradually load upwards until reaching the maximum scale load of the electronic scale, and then unload the load until zero load is reached. The number of load points measured for the first verification of the electronic weighing scale is greater than or equal to 10 points; for subsequent verifications or during use, the number of load points measured can be appropriately relaxed, but should be greater than or equal to 6 points. Sufficient measurement points should be ensured during both loading and unloading processes.
Under the same actual test conditions, the same load is repeatedly placed on the load receiver in the same manner multiple times. Generally, the experiment is conducted by loading the individual weight between 80% of the maximum scale load and the maximum scale load multiple times, and the difference between the results of multiple measurements of the same load should not exceed the absolute value of the maximum allowable error for the corresponding load point, with a minimum of 6 measurements. Zeroing can be done before each loading during the measurement. For example, using an 800g standard weight, zero is set before each loading, and 10 measurements are taken. The repeatability of the piece counting scale is equal to the maximum value of the electronic weighing scale indication error minus the minimum value of the electronic scale indication error after the loaded weight is stabilized.
During indication error verification, the loaded load should be a weight that is one-third of the maximum scale load and maximum tare weight. If multiple weights are used, they should be evenly distributed within the measurement area. According to the surface area of the pan, the pan is divided into 5 areas. A 400g weight is selected and placed in corresponding positions to measure the load error. The load error in 1-5 different areas must not exceed the absolute value of the maximum allowable error for the corresponding load.
For piece counting weighing scales, when equilibrium is achieved at the minimum scale amount, half of the maximum scale amount, and the maximum scale amount, a loose loading or unloading test equivalent to 1.4d of additional load should be performed, and the indication of the electronic weighing scale should change significantly.
High-precision electronic weighing scales combine modern intelligent information processing methods with engineering practices. Research results can be directly applied to the design and development of electronic scales to improve the weighing accuracy and prevent cheating. The development of modern society demands higher requirements for weighing technology. With the continuous development of micro-processing technology and sensing technology, electronic weighing scales will advance towards high reliability, high precision, high performance, and high intelligence.
