How do you chart a negative ppd mantoux test and what do you chart it on?

The Mantoux test determines rather a person has tuberculosis. A patients forearm skin is injected with 1ml tuberculin protein. It is the reaction to the injection that is read. If the inject swells and spreads to 5 mill or more Iit is positive. A negative reading is less then 5mm. The measurement and response is charted on a Medwatch form.