Page - 36 - in Adaptive and Intelligent Temperature Control of Microwave Heating Systems with Multiple Sources

2. IntroductionofHEPHAISTOS 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 02 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 T 1T 2T 3 T e m p e r a t u r e m e a s u r e d b y F O S ( ° C ) M i s m a t c h e d r e g i o n (b) Figure2.18. TemperaturecomparisonbetweenFOSandIRC(aftercompensa- tion). After the compensation, the temperature measured by the infrared camera is further verified. Temperatures of three different locations onthesurfaceofaworkpieceweremeasuredbybothfiberopticesen- sors and the infrared camera. The corresponding temperature curves andfittingresultsareshowninfigure 2.18. Fromtheresult infigure 2.18, it isclearthatafterthecompensationthe temperaturesmeasuredbytheinfraredcameraareclosetothetemper- atures measured by the fiber optic sensors. The differences between them are limited within±2◦C except the mismatched region, which is labeled in both figures in 2.18. This region is caused by the fact that when the temperatures have large changes (see figure 2.18a), the response of the infrared camera is much faster than the response of fiber optic sensors. In other words, this mismatched region is gener- ated because of the time delay of fiber optic sensors. Due to the fast andaccurate temperaturemeasurementresults, the infraredcamerais mainlyusedin the followingexperiments. 36