Research on real-time control system of infrared drying process

The hardware of a real-time data acquisition system for infrared drying fruits and vegetables is designed. The hardware system includes a strain gauge mass transducer, two AD590 temperature sensors, a PCI8310 data acquisition board and corresponding circuits. The mass sensor with strain resistances is fixed on a support beam which is outside of drying chamber, thus the temperature of mass sensor elastomer doesn´t change in drying process. One of temperature sensors is fixed near the silicon heater, the other is near the samples. Physical signals of mass and temperature are converted to faint electric signals, and which are amplified with analog circuits, then analog signals are converted to digital signals by PCI8310 data acquisition board. Digital signals are sent and stored into the PC. The functions of between temperature and mass and output voltage are obtained respectively, and which all have goodness of fit with high R² value.