Can anyone advise regarding using a tube tester?

I recently purchased an old "PACIFIC SALES CORP. CUSTOM BUILT DIAL JUNIOR TUBE TESTER" which I really have no idea how to use properly. I haven't seen a tube tested in 40 years! Even the slightest bit of help would be greatly appreciated. Thanks & God bless!
The tester should have come with a booklet with the tube ###'s and settings for the tester. If it didn't, you may have to search for one!


Paul :-)