Test your valve springs?

This is a quick how to and why you should know a little something about your valve springs, there pressures and how to test them with a small portable Proform spring tester. Normally I don't like battery operated stuff for the shop. When the battery is dead, you need a new one, which for me, could be at 3:00 am, & your screwed. Just the hassle to get one whenever there dead, UGH!