Linear Interpolation refers to the method by which values are calculated from a table when the reference parameter falls between the tables row/column centres.

 

Example

Take the following Warm-Up Enrichment Table. This table has temperature column cell centres at -40, -30, -20, -10, 0 ,+10 etc... degrees. Assume the current Engine Coolant Temperature is -6 degrees. This does not lie exactly on one of these cell centres, but somewhere part way between -10 and 0 degrees. The chart below shows that at -6 degrees, the warm up enrichment is interpolated and found to be 38%.