Aiming at the situation that there are many disputes about the scale value of the truck scale and the actual scale value, this article will talk about the individual view from the design point of view. The initial inherent error of any instrument is actually determined in the design process, not just by changing the degree of division can improve the accuracy of the level. The day after tomorrow (when calibrating) by careful debugging is able to improve certain metering performance, but this is limited.
First, the domestic situation
At present, regardless of whether the use of truck scale units, or manufacturing units like to weigh the truck scale is relatively large, such as the largest weighing for the 120t truck scale indexing value of 20kg, the degree of division is 6000; the maximum weighing 150t truck scale The scale value is set at 20kg, the degree of division is 7500. So why is this happening?
1, Weighing units
For the use of weighing units, there are two guiding ideology: First, that a scale of the scale value of the smaller the better, especially weighing more expensive items; the second is to scale the value of the scale can be as small as possible Some, you can use a large weighing instruments weighing relatively light items, you can save, do not need to buy a small weighing scales.
2, weighing the manufacture and sale of enterprises
Always want to scale the number of degrees as a selling point, as if the product division of the number of more, the better the performance of the same. I do not know that this product to bring their own poor stability of the hidden dangers, as long as the use of the scene a little sign of trouble, weighing the value of the instrument on the changes up and down.
I personally think that the reason for the above situation, there are two reasons: First, the concept is not clear, one is in a private interest.
For the concept of the problem, we must first clear what is the "test scale value" and "actual scale value"?
Check the scale value e: the value expressed in mass units for the rating and verification of the instrument.
Check the degree of sub-n: the maximum weighing and test division ratio, that is, n = Max / e.
Actual scale value d: The following values in mass units:
- for analog indications, refers to the adjacent two ruler mark corresponding to the difference;
- for digital instructions, refers to the difference between the two adjacent signs.
For the issue of self-interest, do not understand the essence of the product, just to see the surface of the phenomenon, can not correctly grasp the performance characteristics of the product, its purpose is to drill management loopholes. As the use of units, often buyers only consider the level of accuracy, and users are considering the long-term stability of the product. As a sales staff, always compete with the competitors, how much the degree of weighing, rather than the reliability of the product, stability.
2, the requirements of the structure
(1) the applicability of the application
The structure of the instrument should be designed to meet the intended use. In the recently published GB / T7723-2008 "fixed electronic weighing", for this article, the current domestic use, the largest weighing 30t to 150t large scale loader, put forward the amount of relative deformation requirements. That is, after the first test after the new installation, the maximum relative deformation of the carrier is not more than 1/800.
(2) the applicability of the use
Weighing the structure should be reasonable, strong, durable, to ensure the use of its measurement period of performance. And, for the installation of the instrument on the basis of its basis should meet the following requirements:
1) must meet the maximum load carrying capacity requirements;
2) The base shall have a straight channel with a length equal to half the length of the carrier (but not exceeding 12 m) and a width equal to the carrier and maintained at the same level as the carrier. Close to the loader at least 3m above the ends of the loader, the application of concrete or other sturdy material manufacturing, can bear all the load with the equalizer loader; the rest of the above-mentioned channel channel should ensure that the vehicle into the slope.