Ok, it looks like I found my OD/converter lockup switches.

I'm certainly "NOT" a programmer, maybe (Dave) KitCarlson can help you

https://www.google.com/search?num=2...p..0.23.2413.0..0i131j0i155i3j0i3.pSHQ7RiV2jI

I did find these

Differential Pressure switch, gauge, transmitter, portables - for air, gases, water, aggressive media, chemicals, non-aggressive media