Testing numbers-How are they decimals?

[camlov2]

Nearly every post I see someone ask "what are your water parameters?" I then see people list of a bunch of test that they have done, many with numbers like PH=8.05, or Nitrites=.5
How are people getting results this accurate? I am using a testing kit where you mix drops of a solution with 5ml of tank water. The tests are not even close to being this accurate. Am I missing something or do all these people all have expensive testing equipment?
Brian

[Savas]

I am using a kit similar to yours (API test kit) and am interpreting the color results against the color cards to approximate a reading, which is in decimals.