Alkalinity test kits

[bassman]

What is the best Alkalinity test kit? Right now I am using Fastest. I doesn't seem very accurate to me. The instructions say to add the testing solution one drop at a time until the water turns a greenish yellow. I could add the entire bottle and never see a green hint to the water, it's always just pale yellow. Is this right? It's the same color after 4 drops as it is after 10.

Is there a more accurate (digital) way of testing?