I'm in the Mech Engineering field, so asking for a little guidance here.
I'm trying to see how I can detect reverse polarity on thermocouples. In this situation there will be a load going into an autoclave that may have well in excess of 100 thermocouples in play. Understandably, they should all be wired correctly... However, we're having situations where they are not, and you can't just stop the load autoclave cycle because there is a bad reading somewhere. When mounted to the tooling, the TC's are wired into a receptacle that is bolted to the tool, and it is not possible to view the wire colors or use other normal means of checking polarity.
Does anyone have knowledge of something that would work for this? A device, a circuit or whatever? Is it possible to use something like an AD594 amplifier (Analog Digital) or maybe a pair of these, and have the TC wired to both, 1 correctly wired, the other in reverse? I tried looking at the voltage generated using just a DMM and then reversing the leads, expecting the voltage to have reversed polarity. Maybe it was just my DMM, but both readings were the same magnitude and polarity, not what I expected - at least regarding the polarity. So this idea might be off the table...
I would like to have something that is portable, preferably battery powered (LED and buzzer indicators), so that the technicians can crawl in and around the load and plug into the TC receptacles to check for reversals, prior to loading, closing and running the autoclave. Not looking to measure anything, just a simple indicator. Would also be looking for this to detect opens (found a video on the AD website that seems to cover this OK, should work with the AD594) and shorts to the metal tools that the TC's are mounted to. (TC's used here are ungrounded J Type).
Thank you for anyone that may have something to offer.
Brad
I'm trying to see how I can detect reverse polarity on thermocouples. In this situation there will be a load going into an autoclave that may have well in excess of 100 thermocouples in play. Understandably, they should all be wired correctly... However, we're having situations where they are not, and you can't just stop the load autoclave cycle because there is a bad reading somewhere. When mounted to the tooling, the TC's are wired into a receptacle that is bolted to the tool, and it is not possible to view the wire colors or use other normal means of checking polarity.
Does anyone have knowledge of something that would work for this? A device, a circuit or whatever? Is it possible to use something like an AD594 amplifier (Analog Digital) or maybe a pair of these, and have the TC wired to both, 1 correctly wired, the other in reverse? I tried looking at the voltage generated using just a DMM and then reversing the leads, expecting the voltage to have reversed polarity. Maybe it was just my DMM, but both readings were the same magnitude and polarity, not what I expected - at least regarding the polarity. So this idea might be off the table...
I would like to have something that is portable, preferably battery powered (LED and buzzer indicators), so that the technicians can crawl in and around the load and plug into the TC receptacles to check for reversals, prior to loading, closing and running the autoclave. Not looking to measure anything, just a simple indicator. Would also be looking for this to detect opens (found a video on the AD website that seems to cover this OK, should work with the AD594) and shorts to the metal tools that the TC's are mounted to. (TC's used here are ungrounded J Type).
Thank you for anyone that may have something to offer.
Brad