Calibration of measuring instruments 

Hello mechons, in this post we are going to explain you about the simple topic in metrology called "Calibrations" in detailed. In calibration of measuring instruments we going to see about what is calibraition, need for calibration in measurements and basics of calibration of measuring instruments.

 

Ok, first let me start explaining with the question that arises in your mind after entering to this page. 

What is calibration?

Calibration is the act of comparison of Measurements to maintain the accuracy of certain measurements. It is the process used for configuration of instruments to provide results within the acceptable range of tolerance. 

In simple words, the calibration is the traceability of measurement by applying the act of comparison with the known standards(Eg: ISO standards, 

Before going to learn about calibration, check whether you know about accuracy, precision, and other static characteristics of Measurements. If not feel free to read our article about Engineering Metrology basics, where we explained all the static characteristics of Measurements such as accuracy, precision, sensitivity, drift and so on. 

Why calibration is done in a instruments? 

The calibration is done 

• To remove the errors that are produced in a process of measurement 
• To maintain the tolerance of error within the range of acceptance. 
• To improve the accuracy and Precision of Measurement and analysis results. 

Need for calibration 

1. To maintain quality control and quality assurance in the production 
2. To obtain the requirements provided by ISO standards
3. To ensure the quality of goods in the global trade. 

Basic requirements for calibrations 

The basic requirements for calibrating are as follows 

• Reference standards 
• Certain environmental conditions 
• Traceability of calibration standards 
• Documentation of Calibration testing certificate. 

Reference / Calibration standards:

Calibration or reference standards are instruments that are used to compared against the less accurate devices for verifying the performance of those less accurate instruments. 

There are certain standards for calibration to check the accuracy. 

SI, BIPM, NMI, Primary standards, Secondary standards, Working standards

What are the standards in Metrology? 

• Primary standards 
• Secondary standards 
• Laboratory standards 
• Working standards 

Environmental conditions for Calibrations:

There are many environmental cases for errors to occur in the process of measuring or calibrating a device. To avoid certain environmental affects there some environmental condition that are required for calibrating a device in a laboratory. 

The environmental affects includes factors like temperature, relative humidity, pressure, sound and vibrations. A laboratory for calibration must need to monitor these environmental situations while doing or before doing the calibrating process. 

1. The temperature must be 68°F(20°C)  acceptable range is ±4°F(±2°C)
2. The Relative humidity should be at 60%. 
3. And at last the place where the testing happens must be free from sound, vibrations and dust. 

Traceability / Uncertainty of Calibration

Traceability:

Traceability is defined as the property of result of a measurement or the value of a standard whereby it can be related with references like National or International standards. 

Uncertainty:

Uncertainty is the way to estimate the amount error associated with the calibration measurement. The higher accuracy of calibration measurement is obtained from the smaller uncertainty value.

Documentation 

The documentation is nothing but getting the documentary or filing the calibrated instruments or devices test report. There certain procedures for documentation of Calibration devices by following those rules laid by NMI's and ISO standards one have to document the calibrated report.

Conclusion

That's all about the Introduction to calibration of instruments, definition, need for calibration, requirements for calibrating an instruments. I hope that you understand this topic. 

If you have any queries or doubts regarding this topic don't hesitate put that in the below-mentioned comments section. We are here for you, we will reply as fast as possible. 

And one more thing Always remember to 

Spark your brain and Throttle your knowledge!.