nomograph

/ˈnɑməˌɡræf/
noun
  1. A synonym for nomogram; a graphical tool for calculating a value by aligning a straightedge with known values on scales.
    • Using a nomograph, the chemist could determine the concentration of a solution without any arithmetic.
    • The textbook included a nomograph to help students convert temperatures between Celsius and Fahrenheit.
    • The old engineering manual had a nomograph for estimating the strength of steel beams.