CJC repair

[ceilingwalker]

Hello, has anyone successfully repaired a CJC (A-BS94238301) for a 1756-it6i series A module? I am commissioning and the electrician was a little careless and broke mine. Of course I have no spare. I was thinking about soldering that tab back on but I am pretty sure that will render the thing useless as I am creating another cold junction. But, I am sure someone on here has been in a similar position and I was looking for some advice, as I wait 3 days for my new one to arrive.......or, if anyone here sells these things and can get it to me quicker, I am open to that also. Thank you

 

[danw]

I’ve probably read 200 thermocouple AI spec sheets over the years annd I can’t remember one that spelled out what tkind of element the CJ was.

There are thermistor CJ’s or RTD CJ’s: most are analog, but some are actually serial output.

But a CJ is never another thermocouple unless an isothermal known-reference-temperature measuring location is being used; meaning a physical ice bath.

So go ahead and try to solder it, solder will not appreciably affect either sn RTD or thermistor (sp?) circuit, if the element itself is not damaged.

Dan

 

[Firejo]

If you're going to repair it I would still order the replacement and install it when it arrives. CJC's are specific to the device they are intended for and are calibrated as such. The solder will change the resistance value thus changing the value the CJC has. If it's noticeable or not depend on the level of accuracy you require.