What is calibration ? why we do calibration ?

Formally, calibration is the documented comparison of the measurement device to be calibrated against a traceable reference device.

Calibration is important because it helps assure accurate measurements and accurate measurements are required for most research, development, and innovation as well as safe and profitable production across virtually all industries of most products and services we use every day.

Calibration is used to ensure that the finished product meets all standards in relation to tolerances, and can be used to measure and record data.

The calibration unit, for example a digital voltmeter would be calibrated from its minimum measure point to its maximum against a known unit, to ensure that it matches, otherwise it would be set to match the calibrator.

Another example would be a set of weights which would be weighed against a Type A weight which is kept in a temperature controlled room to determine the2nd weights true value, any changes would be then made to either add lead to the weight to make it heavier or drill away at the weigh to remove surplus metal. These weights would then become a type A class calibrated mass.

Hope this helps with your query.

Kind Regards

Mr Razzak

Calibration is the method to ensure the accuracy of an instrument and compare it with a standard.....

Calibration in the easiest terms is putting back its reading to the acceptable standard, however there are no same standard from different manufacturer of various measuring devices.But  It is the actual reading base on the process value or actual value, they are not same but the diffrence is negligible. Calibration is needed on the regular basis due to the fact that all measuring devices wear out or the the change of it minimum, maximum referrence, it is the result of stress ( thermal or mechanical), the life span of the device itself, etc.

Imagine if a pressure gauge has difference of .01 bar compare to its actual value, in the production of100,000 cubic meter to30 bars of certain finish product chemical24 hours a day,365 day in a year, imagine the lost........

Regular Calibration is not only for the aspect of production ( gain and lost), but also in respect to safety of the operation, that is testing and calibration...