At our hospital, we have psych tech 1's and 2's. The tech 2's have a four year degree in psych,and run groups, take crisis calls, do impromptu 1:1's, ask non-nursing questions on our 9 page (!!) intake assessment form, do vitals, etc.
The tech 1's are, to be blunt, CNA's in street clothes. They aren't required to have a degree in anything. They do basically the same thing as the tech 2's except run groups. That's the only difference.
1's and 2's respond to take-downs, do vitals, 1:1's with patients in restraints, assist with ADL's, take the patients out for smoke break, help them fill out menus, ad nauseum.
Personally, I think the 1's get a raw deal. Some of them have been working psych for 10+ years and have it all over the ones that just got their BA's. As far as a staffing ratio...