Standards definition & Types of Standards

Hello guy’s !! How are you?… I know you are fine. Today we are going to learn discuss about Standards and comparators.
Engineering have lots of branches and here we will share with you all detailed knowledge of mechanical engineering with the help of best notes.

*Standards :-

Definition of standards :-

Standards a fundamental reference for a system of weights and measures against which all other measuring devices are comparators.
OR
Standard physical representation of a unit of measurement.
OR
Standard is a agreed normal by most techniques community.

Types of standard :

1) Primary standard :

A primary standard will have only one value and it is fix. These are basic standard And instrument which is use to measure the value of primary Standard quantity is called as primary standard instrument.

2) Secondary standard :

It is similar to primary standard if sum error is found in measuring instrument they are Compared with secondary standard. It is use for Comparison with tertiary standard.

3] Tertiary standard :

It is use for reference purpose in workshop and laboratories. It is use for comparison with working standard.

4) Working standard:

This will be use for general application in metrology laboratory. They are available with the less cost.

5) Line standard :

Line standard is the standard in which distance is measured between two lines.
It is quick and easy standard they are not much accurate. The parallel axis error can be generated. Eg . It is use sleel rule.

6) End standard :

The distance between measured two surface is called as end standard.
The high accurate upto 0.005 mm . They are costly and difficult to use.
Eg. The slip gauge end bars.

7) Wavelength standard :

The standard is subjected to destroy day by day of enviromental changes . This concept leads to generate wavelength standards.
                   For this krypton 86 any hot cathode discharge land at 68°k, generate orange radiation and they can be use as ultimate wavelength standard.
          According to this standard,
      1 meter = 1650763.73 x wavelength kr 86

Advantages of standards:

1) It is not affecting by environment.
2) They have doesn’t required to be store.
3)It can don’t be destroyed.
4)Use for comparison with high accuracy.

5) It is use the time consuming in use.

6) It required more cost with comparing to other standards.

Disadvantages of standards:

1) It’s time consuming to use it.
2) It required more cost compare to other standard.

The classification of standards :

1.Line standards :

Their are accuracy is limited. The time of measurement is quick. It is a parallel axis error.They are Line standards cost is low. It is a process of simple.

Ex. It is use steel rule.

2.End standards :

They are accuracy is good. The time of measurement are time consuming. The end standards cost is High. It is error is environment wringing. It is a process of little difficult.

Ex. Slip gauge.

3. Wavelength standards :

Wavelength standards accuracy is Highest. The of measurement are time consuming. The cost is high. It is no error . It is a process of Highly difficult.

Ex. Monochromatic line source.