Disclosed is a food wash sensor system that includes a sensor disposed along a fluid flow path that can circulate a wash fluid through the food wash sensor system. The sensor can detect a concentration of an analyte in the wash fluid. The system also includes a reference fluid reservoir including a reference fluid, the reference fluid including a predetermined concentration of the analyte in solution, a delivery system fluidly coupled to the fluid flow path and operable to supply the reference fluid to the fluid flow path upstream from the sensor while maintaining the sensor in place along the fluid flow path, and a control and monitoring system configured to receive a signal from the sensor, the signal indicating the concentration of the analyte in the reference fluid at a first time, and control calibrating the sensor and validating the sensor over time based on the received signal.