Editing Calibration (section)

===Manual and automatic calibrations===
Calibration methods for modern devices can be manual or automatic.
[[Image:US Navy 040830-N-4565G-002 Fireman Joshua Morgan, of Waco, Texas, calibrates an Engineering pressure gage.jpg|thumb|Manual calibration - US serviceman calibrating a pressure gauge. The device under test is on his left and the test standard on his right.]]

As an example, a manual process may be used for calibration of a pressure gauge. The procedure requires multiple steps,<ref>{{cite book|title=Procedure for calibrating pressure gauges (USBR 1040)|publisher=U.S. Department of the Interior, Bureau of Reclamation|pages=70–73|url=http://www.usbr.gov/pmts/geotech/rock/EMpart_2/USBR1040.pdf |archive-url=https://web.archive.org/web/20130512121612/http://www.usbr.gov/pmts/geotech/rock/EMpart_2/USBR1040.pdf |archive-date=2013-05-12 |url-status=live|access-date=28 November 2014}}</ref> to connect the gauge under test to a reference master gauge and an adjustable pressure source, to apply fluid pressure to both reference and test gauges at definite points over the span of the gauge, and to compare the readings of the two. The gauge under test may be adjusted to ensure its zero point and response to pressure comply as closely as possible to the intended accuracy. Each step of the process requires manual record keeping. 

[[Image:US Navy 040829-N-7884F-006 Machinist Mate 2nd Class Frank Cundiff completes calibration testing on pressure gauges using the 3666C auto pressure calibrator.jpg|thumb|Automatic calibration - A U.S. serviceman using a 3666C auto pressure calibrator]]
An automatic pressure calibrator <ref>{{cite web|title=KNC Model 3666 Automatic Pressure Calibration System|url=http://www.kingnutronics.com/Model%203666%20Automatic%20Pressure%20Calibration%20System.pdf|publisher=King Nutronics Corporation|access-date=28 November 2014|archive-url=https://web.archive.org/web/20141204112439/http://www.kingnutronics.com/Model%203666%20Automatic%20Pressure%20Calibration%20System.pdf|archive-date=2014-12-04|url-status=dead}}</ref> is a device that combines an electronic control unit, a pressure intensifier used to compress a gas such as [[Nitrogen]], a [[pressure transducer]] used to detect desired levels in a [[hydraulic accumulator]], and accessories such as [[Trap (plumbing)|liquid traps]] and gauge [[Piping and plumbing fittings|fittings]]. An automatic system may also include data collection facilities to automate the gathering of data for record keeping.