Thought I'd give these links their own thread so they're easier to find in case someone's looking for info on Watlow SD PIDs (SD3C etc). You need to download the PDF files to view.

Watlow SD series user manual -
https://www.watlow.com/-/media/docum...vember-04.ashx

Watlow SD series calibration Manual-
https://www.watlow.com/-/media/docum.../sdcale-a.ashx

Watlow PID practical guide -
https://www.watlow.com/-/media/docum...cal-guide.ashx

Also Watlow SD retrofit guide -
https://www.watlow.com/-/media/docum...-03042015.ashx

Thought I'd throw in the link for the full Watlow catalogue in case anyone's interested -
https://www.swhc.com/pdf/Catalogs%20...ls_Catalog.pdf