A diagnostic system and method for monitoring operating conditions of turbine machine components (18, 19, 22, 23) that comprise one or more non-contact sensors (24, 31) that detect an operating condition of a turbine component (18, 19, 22, 23) over a defined region of the component. In addition, point sensors (50) are provided that detect and monitor the same operating condition within the defined region. Data generated from the point sensor (50) is used to calibrate the non-contact sensor (24, 31) and the data generated by the non-contact sensor (24, 31).