Summary for rectifier calibration Discussion
Rectifier calibration is discussed as a practical rather than standards-driven issue. Mark Lees asks whether there is a standard for calibrating electroplating and anodising rectifiers, since customer specifications do not mention amps or volts and he wants a reference for any limits set. Ted Mooney replies that he does not know of an industry standard for rectifier calibration limits, but notes that meters can be calibrated and certified. He explains that rectifiers typically use a shunt, often a 50 mV shunt at full nameplate capacity, so a known certified ammeter can be temporarily connected across the shunt to compare readings with the rectifier’s meters. Mark then says there are no industry specs giving actual calibration limits and that his shop has always used a calibrated ammeter; the real question is what standard rectifiers are held to. He concludes that, since their specs only require equipment capable of achieving the coating quality standard and staying within the manufacturer’s claims, they will continue with that approach.
Q. Hi Folks,
Does anyone know of a standard to which electroplating and anodising rectifiers can be calibrated.
None of our customer specs so much as mention amps or volts in relation to the processes.
If we set any limits we would surely need some standard reference to back up our choice.
Thanks and Best regards
Mark Lees
Mark Lees
– A dull grey rock in the Irish Sea
October 25, 2023
A. Hi Mark. I don’t exactly know of any such standards, but it would seem that the meters can be calibrated and certified.
Rectifiers always have a shunt which drives the ammeter, usually a 50 mV one (a drop of 50 mV across the shunt when the rectifier is operating at maximum nameplate capacity). So it should be possible to temporarily attach a known & certified ammeter across the shunt to compare to the meters on the rectifier.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
Thanks Ted, as you say there are no industry specs that give actual calibration limits. We have always used a calibrated ammeter, but the question was asked, to what standard are the rectifiers held. So the can of worms is opened.
Given that the closest any of our specs come to mentioning plating electronics is to say that we use equipment capable of achieving the coating to the defined quality standard, then what ever we do can not be found to be non-conforming.
The only aspect that is perhaps specified is the test frequency, and that they stay within the rectifier manufacturers claims. So I guess we continue to comply with that.
Best regards
Mark
Mark Lees
– A dull, cloudy rock in the Irish sea
October 26, 2023