FEATURE CALIBRATION
IT’S TIME TO TORQUE ISO 6789-2:2017 Having been named as the first laboratory in the world to be accredited to perform
calibrations on hand torque tools to the newly revised BS EN ISO 6789-2:2017 standard, here, Neill Brodey, managing director at Norbar Torque Tools, takes the opportunity to outline the key changes, and what they mean for manufacturers and tool users alike
opposed to a “Calibration Certificate”. Part 2 of the standard now covers the
traceable calibration of the tool, and the requirements of the calibration equipment. This includes highlighting the steps that need to be taken to distinguish uncertainty factors that may cause the calibration values to vary from calibration to calibration for that particular torque tool. Therefore, should a manufacturer also wish to produce a certificate of calibration, they must issue it in accordance with Part 2 of the new ISO 6789 standard. For a new torque tool model that has not yet been seen by the laboratory, calibration to this standard takes around 60 minutes. However, the good news is that what
T
he BS EN ISO 6789:2003 divided requirements into three sections:
design conformance testing, quality conformance testing and recalibration. The intention was to allow different groups of users to identify the relevant clauses for their needs. Coming into play last year, the 2017 edition takes this logic even further and divides the standard into two distinct parts. As a result, the type of documentation supplied with tools has changed. With new requirements for design and quality control, Part 1 relates to the manufacturer and conformance, whereas Part 2 focuses more closely on the calibration of torque tools. In essence, the key changes have been made to protect the word ‘calibration’, which is often used too casually. Calibration is defined by ISO as: “a set of operations that establish, under specified conditions, the relationship between values of quantities indicated by a measuring instrument or measuring system… and the corresponding values realised by the standards.” While most of the requirements from
the 2003 edition are carried into Part 1, there are new design requirements at work of which manufacturers need to be aware. These include the introduction of new maximum torque values for
10 DECEMBER/JANUARY 2018 | INSTRUMENTATION
The update to ISO 6789 will help to provide more clarity in the long run
The 2017 edition divides the standard into two distinct parts
hexagonal output drives, which is of particular interest for torque screwdriver manufacturers. Additionally, changes have been made to certain quality conformance requirements. For example, the time to attain the last 20 per cent of the torque application during testing has now been more tightly defined according to the size of the torque tool. Manufacturers will also now need to state that the tools adhere to the new requirements of Part 1 by supplying a “Declaration of Conformance” with the tool, as
this all means for the tool user is quite simple. Those who were previously content with buying a new torque tool and putting it into service on the basis of the “Calibration Certificate” supplied by the manufacturer, can still do so. However in its place, there will be a “Declaration of Conformance”. The declaration does come with a date of issue, but retesting should take place within 12 months, or 5,000 use cycles of the tool being put into use, rather than the date of the Declaration of Conformance. However, for those working in
environments with stricter quality control processes that require a traceable “Calibration Certificate” issued by an accredited laboratory, it will be necessary to request that the tool be tested to Part 2 of the standard as well. This will provide the tool user with both a “Declaration of Conformance” and a “Calibration Certificate”. While the change may take a little
getting used to, the update to ISO 6789 will help to provide more clarity in the long run, with two distinct parts and separate documentation to match. The 2017 edition is now published and should be used in place of the old 2003 edition, which has been withdrawn. However, in Europe the Euro Norm or EN version has a 12-month period of overlap (February 2017 – February 2018) where either edition can be used.
Norbar Torque Tools
www.norbar.co.uk
/ INSTRUMENTATION
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52
