Editing Calibration (section)

===Intervals===
The exact mechanism for assigning tolerance values varies by country and as per the industry type. The measuring of equipment is manufacturer generally assigns the measurement tolerance, suggests a calibration interval (CI) and specifies the environmental range of use and storage. The using organization generally assigns the actual calibration interval, which is dependent on this specific measuring equipment's likely usage level. The assignment of calibration intervals can be a formal process based on the results of previous calibrations. The standards themselves are not clear on recommended CI values:<ref>{{cite book|last1=Bare|first1=Allen|title=Simplified Calibration Interval Analysis|date=2006|publisher=NCSL International Workshop and Symposium, under contract with the Office of Scientific and Technical Information, U.S. Department of Energy|location=Aiken, SC|pages=1–2|url=http://sti.srs.gov/fulltext/2006/ms2006099.pdf |archive-url=https://web.archive.org/web/20070418143512/http://sti.srs.gov/fulltext/2006/ms2006099.pdf |archive-date=2007-04-18 |url-status=live|access-date=28 November 2014}}</ref>
:''[[ISO/IEC 17025|ISO 17025]]''<ref name="iso17025" />
::"A calibration certificate (or calibration label) shall not contain any recommendation on the calibration interval except where this has been agreed with the customer. This requirement may be superseded by legal regulations.”
:''ANSI/NCSL Z540''<ref>{{cite web|title=ANSI/NCSL Z540.3-2006 (R2013)|url=http://www.ncsli.org/I/i/p/z3/c/a/p/NCSL_International_Z540.3_Standard.aspx?hkey=7de83171-16ff-416c-9182-94c8447fb300|publisher=The National Conference of Standards Laboratories (NCSL) International|access-date=28 November 2014|archive-url=https://web.archive.org/web/20141120230954/http://www.ncsli.org/I/i/p/z3/c/a/p/NCSL_International_Z540.3_Standard.aspx?hkey=7de83171-16ff-416c-9182-94c8447fb300|archive-date=2014-11-20|url-status=dead}}</ref>
::"...shall be calibrated or verified at periodic intervals established and maintained to assure acceptable reliability..."
:''[[ISO 9000#Contents of ISO 9001|ISO-9001]]''<ref name="iso9001" />
::"Where necessary to ensure valid results, measuring equipment shall...be calibrated or verified at specified intervals, or prior to use...”
:''MIL-STD-45662A''<ref>{{cite web|title=Calibration Systems Requirements (Military Standard)|url=http://www.medivactech.com/revA.pdf|publisher=U.S. Department of Defense|access-date=28 November 2014|location=Washington, DC|date=1 August 1998|archive-url=https://web.archive.org/web/20051030004254/http://medivactech.com/revA.pdf|archive-date=2005-10-30|url-status=dead}}</ref>
::"... shall be calibrated at periodic intervals established and maintained to assure acceptable accuracy and reliability...Intervals shall be shortened or may be lengthened, by the contractor, when the results of previous calibrations indicate that such action is appropriate to maintain acceptable reliability."