Questions and Answers
Can I continue to use the item if there are reading(s) found to be out of tolerance (OOT)?
It depends on the purpose and usage of this item.
The user should compare the calibration report with the application of the device and decide accordingly.
Although simple acceptance rule has been applied as the default decision rule by MD, you can and should decide the usability based on your internal procedures.
What happens when the calibration shows that the readings are out of tolerance (OOT)?
When the calibration and measurement is completed and the readings are found to be out of tolerance, MD’s laboratory will compare the readings with the last calibration report(s), if available.
If the last calibration report is not available, a second-person check may be activated (if resources allows) and confirm the readings are out of tolerance.
The subsequent procedures such as reporting and invoicing will continue even if the readings are found to be OOT.
Why are the readings found to be out of tolerance (OOT)?
There are many possibilities for OOT readings. As the laboratory is not privy to the condition and usage of the gauge over time, it will be difficult to pinpoint the exact reason(s) for OOT.
One of the most common reasons will be due to wear and tear or the tolerance being applied is too tight for the usage. In cases where the tolerances are applied too tight, please let us know at the quotation stage your specifications/ tolerances so that these can be placed in the reports before calibration starts.
Where are the tolerances taken from? Are tolerances going to be reported in all reports?
The tolerances are commonly taken from the International Standards (eg: BS, JIS, ISO, ASME, ANSI, etc…), Manufacturers or End Users.
Tolerances are not always provided on the calibration reports as the device may have been an obsolete model or cannot be found in International Standards or Manufacturer’s catalogues. In these cases, if you wish to include tolerances in the report, kindly let us know at the quotation stage.
How is error computed?
Error = Readings from UUT – Reference Readings
How is error expressed as “% of readings” calculated?
Error as % of Readings = [Error] / [Readings] x 100%
How is error expressed as “% of full scale” calculated?
Error as % of Full Scale = [Error] / [Full Range] x 100%