Definition - What does Nomograph mean?
A Nomograph is a geographical calculating tool that is designed for approximate graphical computation of any function. The Nomograph, also known as a nomogram, contains a set of n scales, one each for all the variables in the equation. If the value of n-1 is known, the values of the other unknown variables can be easily found. The relationship between the values that are unfixed can be studied easily by fixing values of some of the variables. Nomographs were flourished for roughly around 75 years in various different contexts as they provided accurate and quick calculations before the pocket calculators came into existence.
Petropedia explains Nomograph
A Nomogram is used to obtain reliable results quickly by drawing one or more lines. It is a two-dimensional diagram. The user is not required to know the equation to calculate the result. Nomograms incorporate explicit and implicit knowledge naturally into their designs. To create a larger Nomograph for more accuracy, the nomographer includes only scale ranges which are of interest to and reasonable for the problem. They also include various useful marking like colored regions and reference labels. These are useful for the users as user guideposts. They are used in various applications in which the approximate answers are useful and appropriate.