Skip to main content

Total Indicator Reading

Total Indicator Reading (TIR) measures roundness in relation to a center line.

TIR is expressed in total diametric deviation.
Example: ±0.004 (0.10mm) deviation is defined as 0.008 (0.20mm) TIR.

TIR is the total lateral distance traveled by the indicator needle resting against the O.D. of a round part, as the part is turned one full revolution.

Need help solving a tough engineering problem?