在非标准温度下进行的维度测量的不确定性
1National Institute of Standards and Technology, Gaithersburg. MD 20899-0001.
概括
温度和热膨胀的不确定性显著影响长度测量的准确性. 这项研究量化了各种材料的这些效应,对于精确的维度计量学至关重要.
科学领域:
- 计量学 计量学 计量学
- 材料科学 材料科学 材料科学
- 热力学是一种热力学.
背景情况:
- 维度测量对温度变化非常敏感.
- 精确的长度测量需要考虑材料的热膨胀.
- 与标准参考温度 (20°C) 的偏差带来不确定性.
研究的目的:
- 分析温度和热膨胀不确定性对长度测量不确定性的影响.
- 评估来自各种热膨胀系数来源的不确定性.
- 评估与1990年国际温度尺度 (ITS-90) 相对的温度测量的不确定性.
主要方法:
- 从各种参考来研究热膨胀系数的不确定性.
- 使用不同类型的温度计检查温度测量的不确定性.
- 分析ITS-90实现的温度控制水平.
主要成果:
- 因热效应而导致的长度测量的量化扩展不确定性.
- 从热膨胀系数值确定了不确定性的主要贡献者.
- 评估温度测量精度对维度计量学的影响.
结论:
- 温度和热膨胀的不确定性是长度维度测量中的关键因素.
- 准确的材料性能数据和精确的温度实现对于减少测量不确定性至关重要.
- 这种分析为管理非标准温度环境中的不确定性提供了一个框架.
相关概念视频
02:46Uncertainty in Measurement: Reading Instruments
38.4K
Counting is the type of measurement that is free from uncertainty, provided the number of objects being counted does not change during the process. Such measurements result in exact numbers. By counting the eggs in a carton, for instance, one can determine exactly how many eggs are there in the carton. Similarly, the numbers of defined quantities are also exact. For example, 1 foot is exactly 12 inches, 1 inch is exactly 2.54 centimeters, and 1 gram is exactly 0.001 kilograms. Quantities...
38.4K
03:37Uncertainty in Measurement: Accuracy and Precision
74.0K
Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy of their results. Measurements are said to be precise if they yield very similar results when repeated in the same manner. A measurement is considered accurate if it yields a result that is very close to the true or the accepted value. Precise values agree with each other; accurate values agree with a true value.
74.0K
01:23Dimensional Analysis
919
Dimensional analysis is a powerful tool that is used in physics and engineering to understand and predict the behavior of physical systems. The basic idea behind dimensional analysis is to express physical quantities in terms of fundamental dimensions such as the mass, length, and time. Derived dimensions like the velocity, acceleration, and force are derived from the combinations of these fundamental dimensions.
Dimensional analysis allows us to analyze and compare physical quantities on a...
Dimensional analysis allows us to analyze and compare physical quantities on a...
919
01:08Problem Solving: Dimensional Analysis
3.5K
Every mathematical equation that connects separate distinct physical quantities must be dimensionally consistent, which implies it must abide by two rules. For this reason, the concept of dimension is crucial. The first rule is that an equation's expressions on either side of an equality must have the exact same dimension, i.e., quantities of the same dimension can be added or removed. The second rule stipulates that all popular mathematical functions, such as exponential, logarithmic, and...
3.5K
01:15Distance Corrections
52
To achieve precise distance measurements, especially in surveying and construction, certain corrections must be applied to account for potential sources of error like the standardization errors, temperature variations, and slope adjustments.Standardization error emerges when measurement equipment undergoes changes, such as wear, repairs, or weather impacts. To address this, surveyors compare the equipment’s readings to a standard. This process identifies any deviation that might lead to...
52
00:59Uncertainty: Overview
603
In analytical chemistry, we often perform repetitive measurements to detect and minimize inaccuracies caused by both determinate and indeterminate errors. Despite the cares we take, the presence of random errors means that repeated measurements almost never have exactly the same magnitude. The collective difference between these measurements - observed values - and the estimated or expected value is called uncertainty. Uncertainty is conventionally written after the estimated or expected value.
603