PROFILOGRAPH TESTING accurately measures surface roughness through a computerized recorder capable of graphing a pavement profile both vertically and horizontally. The information it collects is used to calculate the International Roughness Index (IRI), which is expressed in units of inches/mile or millimeters/meters.

What does Profilograph mean?

1 : an instrument borne on wheels for recording automatically the profile of the land over which it travels. 2 : an instrument for measuring smoothness of a surface (as of a metal casting) by amplification of the minute variations from the plane or arc of smoothness.

What is pavement smoothness?

Pavement Smoothness (sometimes termed roughness – the opposite of smoothness) is ultimately a measure of the drivers' comfort. It is commonly estimated using a pavement profile (a measure of minute elevation changes in the pavement surface). ... Measuring techniques have evolved over time.