The fluid path systems have been widely used in many industries and civil society. In order to maintain the stability of system and avoid relative emergencies, the authors have to measure and monitor important parameters of fluid such as the temperature, pressure and flow. This study presents one method for designing the multi-channel measuring system that includes modern digital data processing as micro processing, programmable logic controllers, and field-programmable gate array. By using the measured information processing algorithm by combination method of a second-order interpolation through three succeeding data points with the loop transformation, not only errors of system are significantly reduced but also data processing speed is improved. The results calculated by using the MATLAB program have shown the ability to reduce errors of measurement devices.