Infrared Thermometry System for Temperature Measurement in Induction Heating Appliances

The theoretical analysis and design of an infrared (IR) thermometry system for temperature measurement in domestic induction hobs is presented together with the results of its implementation. The system includes an InGaAs PIN photodiode and a preamplifier which detects the IR radiation emitted from the bottom of the cookware and the glass-ceramic top. The analysis includes an algorithm to discount the contribution of the glass-ceramic material from the total signal. The proposed system has been designed for frying temperature measurements (140 ^°C-180 ^°C) and tested in the cooking range from 120 ^°C to 200 ^°C for cookware made of different materials. Finally, the measurement temperature errors were around 20 ^°C for almost any emissivity of the cookware.