Scale and precision are two important concepts that describe the attributes of measuring tools, but what is the difference
between them? Many people tend to confuse these two concepts. Today, we will delve into the distinction between
scale and precision to help everyone better understand and use measuring tools.
I. What is a scale?
1. A scale can be understood as the marks on a measuring tool used to indicate the measured value.
For example, the millimeter marks on a ruler, and the milliliter marks on a graduated cylinder, are all scales.
The scale value refers to the numerical difference between adjacent two scale lines.
2. The smaller the scale value, the more precise the reading of the measuring tool is.
However, this does not necessarily mean that the measurement result is more accurate.
For instance, a vernier caliper has a scale value of 0.02 millimeters, while a steel tape measure might have
a scale value of 1 millimeter. Although the scale value of the vernier caliper is smaller and the reading is more precise,
if the operation is improper, the error in the measurement result may be greater than that of the steel tape measure.
II. What is Precision?
1. Precision refers to the degree of closeness between the measured result and the true value.
The higher the precision, the closer the measured result is to the true value, which means the measurement error
is smaller. The measurement error of a high-precision vernier caliper is usually within 0.02 millimeters,
while the measurement error of an ordinary tape measure may be around 1 millimeter.
2. There are numerous factors influencing the accuracy, including the quality of the measuring tool itself,
the correctness of the measurement method, the influence of environmental factors, and human errors, etc.
Even for the same measuring tool, its accuracy may vary under different measurement conditions.
III. Relationship between Scale and Precision
1. There is a certain relationship between scale and precision, but they are not equivalent concepts.
Measuring tools with smaller scale values can provide more precise readings, which lays the foundation
for improving measurement accuracy. However, this does not mean that their precision is necessarily high.
High precision requires a smaller error range, which requires multiple aspects of guarantee such as the quality
of the measuring tool and the standardization of the measurement method.
2. It can be understood in this way: The scale value determines the smallest reading unit of the measuring tool,
while the accuracy reflects the reliability of the measurement result. Measuring tools with smaller scale values
have higher resolution, but the level of accuracy also depends on other factors.
IV. How to Improve Measurement Accuracy?
1. Select the appropriate measuring tool: Based on the size and precision requirements of the object being
measured, choose the appropriate measuring tool. For example, when measuring the length of a part,
if the precision requirement is high, a vernier caliper or a micrometer can be selected; if the precision requirement
is not high, a steel tape measure can be chosen.
2. Standardize operation procedures: Operate strictly according to the correct measurement methods.
For example, when reading the value, the line of sight should be perpendicular to the scale line to avoid parallax;
apply force evenly to avoid deformation, etc.
3. Control environmental factors: Temperature, humidity and other environmental factors can affect the measurement
results. Therefore, efforts should be made to maintain the stability of the measurement environment.
4. Taking the average of multiple measurements: Conducting multiple measurements can reduce random errors
and improve measurement accuracy.
V. Case Analysis
For instance, there are two rulers. One has a scale value of 1 millimeter, and the other has a scale value
of 0.5 millimeters. The ruler with a scale value of 0.5 millimeters can measure more precisely to 0.5 millimeters.
However, if the material of this ruler is poor and it is prone to deformation, then its measurement accuracy
may be lower than that of the ruler with a scale value of 1 millimeter.
