is there such a thing as a digital pressure gauge?

I'll comment but not REALLY answer your question.

Waste Management at one time bought some kind of scale or measuring device on their frontend load trucks when I worked for them. I dont think they lasted very long & were expensive for them to keep up mechanically. However, they would go in & out of the landfill several times a day & it would be muddy or dusty etc, so I am not sure how well they would hold up otherwise.

In short, I know someone makes a "permanate" scale of sorts that you can mount on your truck/trailer to read the weight at all times without manually putting out portable scales etc every time. I am not sure of the cost etc.

Sorry I couldn't be of more help but hope this puts you on the right track.