[Mitch//pa]

You'll get a better idea of the flow of spark into the cap if you place the spark tester in series of the coil wire instead of the plugs... This will be a more rapid and steady flash unless you have an issue. Checking them at the plugs is good for diagnosing a misfire or cylinder drop out. Condenser wise I keep a few good modern short proof ones on hand and never test them, as its to subjective...kind of like using a vacuum gauge