Abstract: In an instantaneous profile gauge system, the scanning pyrometer is used to measure temperature of the hot strip section. The acquired temperature data are applied in strip thickness compensation, so that the compensated thickness can be fed back to the rolling mill to adjust the strip profile. In order to acquire real time strip temperature data, an OPC client is needed to interact with OPC server of the scanning pyrometer. The OPC data access specification was introduced and analyzed. In the Visual C++ development environment, an OPC client program was implemented based on the Microsoft active template library (ATL), so that data items of the scanning pyrometer can be acquired. The acquired temperature data were delivered to temperature compensation module for thickness correction and a good correction result was obtained.