Editing Calibration (section)

===Purpose and scope===
The calibration process begins with the design of the measuring instrument that needs to be calibrated. The design has to be able to "hold a calibration" through its calibration interval. In other words, the design has to be capable of measurements that are "within [[engineering tolerance]]" when used within the stated environmental conditions over some reasonable period of time.<ref name="HaiderAsif2011">{{cite book|last1=Haider|first1=Syed Imtiaz|last2=Asif|first2=Syed Erfan|title=Quality Control Training Manual: Comprehensive Training Guide for API, Finished Pharmaceutical and Biotechnologies Laboratories|url=https://books.google.com/books?id=-djll_c9Z9MC&pg=PA49|date=16 February 2011|publisher=CRC Press|isbn=978-1-4398-4994-1|page=49}}</ref> Having a design with these characteristics increases the likelihood of the actual measuring instruments performing as expected.
Basically, the purpose of calibration is for maintaining the quality of measurement as well as to ensure the proper working of particular instrument.