I bought a ballast tester from Greenlee.
A waste of money IMO.
First to use it you need new ballast of exactly same type and brand ballast of the one you want to test.
Then you have to unwire the one to be tested and compare readings from the old one to the new one.
At the labor rate of an electrician around here it is more cost effective to just replace the ballast in the first place after trying new lamps and taking a look at the connections.
Bob
