This article mainly introduces the error standards for weighing scales and provides a detailed answer to the question: What is the allowable error range for electronic weighing scales of different specifications? According to relevant metrological regulations, the allowable error for weighing scales is 0.3%, which means that within ± 3 ‰, it is considered normal. The allowable error is determined based on the weighing range and can be adjusted freely through weighing instruments. Generally, the allowable error for weighing scales over 50 tons is 20kg, and for weighing scales over 150 tons, it can be adjusted to 20kg or 50kg. This is calculated based on the calibration scale value, not the displayed scale value. In practical use, the error standard is often higher than the calibration error standard.
weighbridgeError standard:
(1) 0~500e (0 to 10 tons): The use error is 20kg (e);
(2) 500e~2000e (10 tons to 40 tons): The error in use is 40kg (2e);
(3) 2000e (i.e. 40 to 100 tons) and above: The error in use is 60kg (3e).
Additional explanation: The calibration error of the metrology institute is half of the error in use. Here are two examples:
1、 Analysis of Standard Error of Weighing Scale
The maximum allowable error for the national standard 100 ton weighing scale is+0.5e; for 500 ＜ m2000, the maximum allowable error is+1.0e; for 2000 ＜ m10000, the maximum allowable range is+1.5e; subsequent verification: the maximum allowable error is also based on the above standards. In use inspection: The maximum allowable error for in use inspection is the maximum allowable error for verification. Repeatability experiment: for the same load, the difference between the results obtained from multiple weighings should not exceed the maximum allowable error of the scale. Conduct a partial load experiment: The error of the readings of the same weight at different positions shall not exceed the maximum allowable error of the weighing.
When the value of 100 tons of goods weighed is 99980kg-100020kg, it is normal.
2、 Standard Error Analysis of 1-Ton Electronic Weighing Scale
The 1-ton electronic weighing scale in small scales has an accuracy level of 3 and a maximum range of 1 ton. The calibration division number is n=3000, and the division value is 5/2 optional. If the division value is 0.5kg, a measurement error of 3kg is allowed between the maximum scales. If n does not exceed 3000, you can only set the division value to 0.5kg. If the tolerance does not meet the requirements, the weighing scale or sensor needs to be replaced. If the sensor level is high, n can exceed 3000, such as greater than 5000, so you can set a 0.2kg division value. The corresponding tolerance has also been reduced, which basically meets the needs of your factory. If the calibration scale does not exceed 3000 and the maximum weight is 1 ton above ground, then e=0.5kg and the calibration scale is 2000. The maximum allowable deviation for calibration is plus or minus 0.5kg. When comparing two above ground scales, the maximum allowable deviation for calibration should be considered, with one maximum positive deviation and one maximum negative deviation being only 1kg. According to regulations, the error during testing should be doubled to 2kg.
Additional explanation: The digital indicator scale can be set by oneself, and the actual division value d is set by oneself. The calibration division value e is used for grading and calibration, and the calculated tolerance is independent of the set actual division value.
Summary: A weighing scale is a commonly used large measuring instrument, commonly known as a truck scale, which is usually installed outdoors for use. It is mainly used for weighing various large goods and has a wide range of applications in measuring the weight of goods circulating in various units. In the process of using a weighing scale, various errors are inevitably generated, and there are also many problems during use. Studying these problems and calculating and reducing errors can help to weigh objects more accurately. Shanghai Zhirong weighbridge manufacturer has conducted research on the error calculation method of weighbridges, and based on years of production and maintenance experience, has deeply explored the working principle, error causes, and error calculation methods of weighbridges, and summarized some effective error control methods.