If you've experienced a calibration failure and require a new tester, take a look at this! ukposts.info/have/v-deo/faV0qKZuf4FewHU.html

What / who calibrates a calibrator? Calibration labs will work to "ISO/IEC 17025 - Testing and calibration laboratories" Ideally these labs will have UKAS Accreditation, and their scope can be checked on the UKAS web page. (UKAS = UK Accreditation Service) It may be that a company offering calibration services will be approved to do so by another company who is UKAS accredited. Audits will be performed to make sure this company is following the procedures to which it was approved and it will likely have ISO 9001 approval. (ISO 9001 is the international Standard for Quality Management.)

All calibration should be traceable back to national standards which in the UK is NPL.

My megger 1552 was not giving stable continuity reading, i asked them to test it and they said £250+VAT just for finding the problem and the repair will be extra( although i bought it for £200 (used) three year ago.)

I've got some checkboxes, Megger and Kewtech being the main ones, which I use, and record , every month to show the MFTs I have, have not gone out of range. My NICEIC assessor put me into this, and as long as i keep a record showing no excessive deviation from when the MFTs came back from the Calibration House, they are happy. For belt and braces, i send the checkboxes for calibration every few years. I saved a fair bit of money doing that.

Most MFTs fail due to Capacitor failures which if you handy with a soldering iron you can replace yourself and very helpful people like Big Clive can show you how to make a test device

I have a failed calibration mft, but fortunately its only the 10mA RCD test function. Which I never use.

As an ex iso 17025 cal lab manager, i can confirm the calibration equipment used on site is ultimately traceable along with any measurement uncertainty right back to the S.I. standards in France. What This means is that the national standards lab in any country (apart from the USA, they use some funny ANSI srandard) gets their their reference instruments calibrated against a traceable unit and in turn use that to calibrate instruments used to perform "lower level" calibrating. This means if everything is done correctly you can trace your calibration right back to the S.I standard unit for that calibration point. . Yep, im being geeky, but it is an interesting field. The labs even check items of unknown (except to the national lab) calibration to see if they all get the same results, especially in metrology

Megger like to use clean components in the 1720 range. This way unless you have all the data down to component level you’re unable to complete a repair, which results in sending it to the direct.

So faulty mft,s can be fixed ---- at a price

Could you enlight us a little more what happens if tester fails calibration? All right, they put it in the corner - what's next? How much is to adjust/repair that faults in terms of most important thing - money? Who is doing it? Do manufacturers give somebody right to repair testers they produce? Can you show us a dark side of it, where is not all smiles

Yorkshire owt f nowt.

The chicken came first