Calibration vs Validation
Calibration and validation are two processes in manufacturing to guarantee the quality of the product or related apparatus. With the calibration, the measurements are compared with an accepted reference measurement, to assure the considered measurements comply with the requirements. With the validation, the performance, quality, and other operating parameters of a system are tested to verify that they comply with the requirements.
What is Calibration?
Calibration can be considered as a comparison between two entities, to ensure one is equal to the other, within the accepted tolerances. The entity used as a reference in the comparison is known as the standard.
Calibration is often required in instruments, to ensure that they produce accurate results. Consider a spring scale. The accuracy of the measurements made by this type of scale is directly related to the stiffness of the spring used. The indicator face is marked with graduation, to give the corresponding weights. In this process, a known set of weights is used to achieve the proper extension length of the spring. This process can be considered as calibration. Also, the usage causes the stiffness of the spring to vary, and the values indicated are not going to be accurate. Therefore, the scale has to be compared with the known set of weights and corrected to give proper weights. This is also a calibration (or rather re-calibration).
The calibration process is done for new instruments, instruments after repair and component replacement, or after a specified time interval or a certain usage hours, before a critical measurement, after a serious operation with the instrument, or a sudden change in the instrument environment, or when the measurements are questionable.
What is Validation?
Validation is a process to ensure that the system, a service, or a product meets its requirements and specifications. Often it is a verification done by a third party, to ensure the buyer is supplied with the product which meets the specifications, requirements, and accepted standards and a documented results are produced at the end of the process.
Process of validation can be categorized as follows;
Prospective validation: Validation conducted before the distribution of a new product or a product made under a modified manufacturing process, where the modifications might cause variation in the product’s characteristics.
Retrospective Validation: Based upon accumulated production, testing and control data, validation can be carried out for a product already in distribution.
Locational or Re-Validation: After a certain time has elapsed, repeating the validation for a method that already had been validated.
Concurrent Validation: Control activities of the validation method are performed during ongoing testing, to approve the method of control and ensure the validation results are valid.
What is the difference between Calibration and Validation?
• Calibration is a process to assure that the measurements of an instrument is accurate, by comparing it to a standard (a reference).
• In a broader sense, during a validation process, the quality in terms of the performance, operation, and compliance with the specifications and requirements are tested and documented.