This paper presents an application of LabVIEW graphical programming and FPGA technology in the area of sensor calibration. A water quality sensor calibrator based on compact reconfigurable FPGA core that works under a real-time controller is described. The system provides automatic calibration of stand alone sensors such as turbidity, pH or conductivity using different calibration solutions that are injected in the calibration vessels using a set of pumps and electro valves. The control of the system actuators, data acquisition, primary filtering of the acquired signals and sensor modelling is implemented using the FPGA core included in the compact reconfigurable I/O system. To programme the FPGA the LabVIEW FPGA Module that extends LabVIEW graphical development to reconfigurable FPGAs on National (NI) Reconfigurable I/O (RIO) hardware was used. Parts of data processing, data logging, and data communication are embedded on the real time controller that is connected to the FPGA core through a PCI interface.