Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision
Previous revision
Next revisionBoth sides next revision
articles:optimizing_calibration_intervals [2019/03/19 21:38] – [Reducing Waste: Through Optimizing Calibration Intervals] rrandallarticles:optimizing_calibration_intervals [2020/01/14 13:17] – [Reducing Waste: Through Optimizing Calibration Intervals] rrandall
Line 5: Line 5:
 Why should you care about optimizing calibration intervals? Why should you care about optimizing calibration intervals?
  
-Most M&TE are on arbitrary 12 month calibration intervals... as if “one size” fits all. These are typically “manufacturer recommended intervals” - which are often extremely conservative because the manufacturer wants their calibration labs to stay busy. And most companies happily pay them to do so. Yes… over-calibrating M&TE reduces risk… but only to a degree((A MUCH better way to reduce risk is to increase the minimum "Accuracy Ratio" between the M&TE and the tolerance of the characteristic being measured, but that's a topic for a separate article.)). Is it efficient or cost effective? No. Does the reduction in risk justify workers being without M&TE or the company paying excessive amounts for this “over calibration”? In most situations, the answer is a resounding NO!+Most M&TE are on arbitrary 12 month calibration intervals... as if “one size” fits all. These are typical “manufacturer-recommended intervals” - which are often extremely conservative because the manufacturer wants their calibration labs to stay busy. And most companies happily pay them to do so. Yes… over-calibrating M&TE reduces risk… but only to a degree((A MUCH better way to reduce risk is to increase the minimum "Accuracy Ratio" between the M&TE and the tolerance of the characteristic being measured, but that's a topic for a separate article.)). Is it efficient or cost-effective? No. Does the reduction in risk justify workers being without M&TE or the company paying excessive amounts for this “over calibration”? In most situations, the answer is a resounding NO!
  
-If M&TE calibration intervals were optimized based upon performance, optimal calibration intervals for some instruments might be 18 months, 24 months, or even longer. This results in immediate tangible cost savings. And while a few instruments may require shorter calibration intervals (e.g., 9 month intervals), immediate intangible savings are realized through the reduction of risks.+If M&TE calibration intervals were optimized based upon performance, optimal calibration intervals for some instruments might be 18 months, 24 months, or even longer. This results in immediate tangible cost savings. And while a few instruments may require shorter calibration intervals (e.g., 9-month intervals), immediate intangible savings are realized through the increased confidence in the reliability of the M&TE.
  
-One company I visited, had over 13,000 instruments in their calibration system. They'd contracted all of the calibrations with a metrology laboratory who "optimized" their calibration intervals for them. The number of instruments found "Out-of-Tolerance" dropped from 5% (650 instruments) per year to less than 0.5% (only 65 instruments)!+One company I visited, had over 13,000 instruments in their calibration system. They'd contracted all of the calibrations with a metrology laboratory that "optimized" their calibration intervals for them. The number of instruments found "Out-of-Tolerance" dropped from 5% (650 instruments) per year to less than 0.5% (only 65 instruments)! This reduced their risk (of "Out-of-Tolerance" instruments being used to inspect product), reduced their administrative costs (associated with performing "Out-of-Tolerance" impact analysis), and reduced their total annual cost for calibration services (fewer calibrations were performed)!
  
 +<note>An excellent paper on this topic is [[https://us.flukecal.com/literature/articles-and-education/electrical-calibration/papers-articles/calibration-intervals-manuf|"Calibration Intervals, A Manufacturer's Perspective"]], written by David Deaver - [[https://us.flukecal.com|Fluke Corporation]].</note>
 ===== Methodologies for the Determination of Calibration Intervals ===== ===== Methodologies for the Determination of Calibration Intervals =====