Hardness Tester

I'm going to look at one and was wondering if anyone knows how to use one so I can test.
I have used a hardness tester before, long ago, but I don't know if it was an Avery, and can't quite remember the details.
I think they go like this for test block of 62 HRC:Install diamond indenter.Install 150kg weightput block on anvil.move anvil to contact indener until a needle points up (usually a separate needly to the main scale).Apply the load (Not sure how ... I remember pushing a button, so the thing was probably electric, but others have levers and knobs, so this is where I really need help).Sometimes, I think you have to pre-set the load by moving a leaver or winding the anvil until another scale points appropruately for the C scale. Is this the case for Avery? Then click another leaver or button to apply load sequence.Read HRC directly off scale (although some just measure penetration and you need to do a calc like 100 - d/2. I don't think this is case with the Avery).Wind the block back down.
Any tips - just so I can test it sort of works for HRC?
Ames hardness testers