Line and end standards plan: Introduction Line and end measurements

LINE AND END STANDARDS

Plan:

1. Introduction
2. Line and end measurements
3. Transfer from Line Standard to End Standard
CHIZIQLI VA YAKUNIY O’LCHASHLAR

Reja:

1. 
   Kirish
   

2. 
   Chiziqli va yakuniy o’lchashlar
   

3. 
   Chiziqli standartdan yakuniy standartga o’tish
   

Introduction
Human beings have always been innovative and have exploited the natural resources of the earth to manufacture products and devices that satisfy their basic needs and desires. They have always experimented with the form, size, and performance of the products they have invented. During the medieval period, the measurement process underwent an evolution and people accepted the process in specific trades, but no common standards were set. Generally, these measurement standards were region-dependent, and as trade and commerce grew, the need for standardization was also realized. In fact, it would be impossible to imagine today’s modern world without a good system of standards of measurement. Mass production, an idea generated during the last industrial revolution, has become very popular and synonymous with the present manufacturing industry, and a necessity for manufacturing identical parts. Today, almost all manufacturing units practise the principle of interchangeability of manufacture. In order to accomplish complete interchangeability of manufacture in industries, it is essential to a have a measurement system that can adequately define the features of the components/products to the accuracy required.

Line and end measurements
We all know that sometimes distances have to be measured between two lines or two surfaces or between a line and a surface. When the distance between two engraved lines is used to measure the length, it is called line standard or line measurement. The most common examples are yard and metre. The rule with divisions marked with lines is widely used. When the distance between two flat parallel surfaces is considered a measure of length, it is known as end standard or end measurement. The end faces of the end standards are hardened to reduce wear and lapped flat and parallel to a very high degree of accuracy. The end standards are extensively used for precision measurement in workshops and laboratories. The most common examples are measurements using slip gauges, end bars, ends of micrometer anvils, vernier callipers, etc. For an accurate measurement, it is required to select a measuring device that suits a particular measuring situation. For example, for a direct measurement of the distances between two edges, a rule is not suitable because it is a line-measuring device. However, a comparison of characteristics of the line and end standards clearly shows that the end standards provide higher accuracy than line standards.