Recommendations for Field Engineer

[Vtile]

I would say that a person for no prior experience of HP rpn machines, go with DM42. The is no algebraic entry at all (41 or 42) everything is done with postfix operations:
1 1 + is the same as 1 + 1

That said there might be full professional module for HP41 and DM41 for your field of engineering.

You can try out Free42 from Thomas Okken in your phone to evaluate if you like it or not. Dm42 from Swiss Micros is actually a physical device running Free42.

What do acronym DMS stand for?

DM41 and HP41xx are more "hackable" and it is more like a microcontroller in a box (a hobby project with endles modules etc. what I have understood, a fine machine especially for those who have prior experience of HP41xx).