The Minimum Weighing Capacity is the smallest weighing value that a scale can have to ensure that there is no excessive relative error in the weighing results. What should be the “minimum weighing capacity” of a scale? This is a question that should be emphasized for each scale in our practical work. Because there are some scales using units, when choosing scales, they only consider to save purchasing funds, reduce the number of scales purchased as much as possible, and if they can use one scale to weigh the incoming and outgoing substances of the unit, they are definitely not willing to purchase two scales with different weighing capacity.
We are only discussing the minimum weighing capacity of “nonautomatic scales”, not the minimum weighing capacity of the relevant “automatic scales”. The reason is that each of the six categories of “automatic scales” has different minimum weighing requirements, and of course they are all designed to control the accuracy of their weighing.
In the 2006 edition of the International Recommendation R76 “Nonautomatic Weighing Instruments”, the minimum weighing capacity of each of the four different accuracy classes of scales is specified and clearly labeled “Minimum Weighing Capacity (Lower Limit)”.
Therefore, as a manufacturing enterprise and the metrological administrative department should make it clear to the scale users that they must deploy scales with different weighing ranges in their enterprises to ensure that different scales are used for substances of different weighing weights, so as to ensure the reasonableness of trade settlement.
In China’s current measurement and verification regulations, whether a scale can meet the requirements of the relevant regulations, in the first and subsequent verification of at least five selected scales, and must include: the minimum scale, the maximum permissible error change in the scale (500e, 2000e for the medium accuracy level; 50e, 200e for the ordinary accuracy level), 1/2 maximum scale, maximum scale. If the minimum weighing capacity is only 20e, or only 50e, when the allowable error is 1 calibration division, the relative error is only 1/20 or 1/50. This relative error is meaningless to the user. If the use of the unit explicitly requested to determine the minimum weighing capacity of more than 500e, the certification body can not be 500e of this weighing capacity for certification.
For the measurement uncertainty assessment of an electronic weighing machine, the maximum weighing capacity, 500e, 2000e are generally selected
three weighing points, and less than 500e weighing point is no longer as an assessment of the project. Then less than 500e weighing point of the weighing accuracy, can also be understood as not as the content of the assessment, which must now give rise to the “minimum weighing” this point how to choose the goal.
Post time: Sep-25-2023