Microwave heating is very popular for quick and selective digestion of materials in various industries e.g. Food and feed, Pharmaceutical, Chemistry, Environmental, etc. In these application, the sample is mixed into an acid mixture and heated to high temperature, up to 250 or 300⁰C. However, spontaneous heating of acid mixture induces exothermic reaction resulting into very rapid change in temperature and pressure.
Therefore, faster and accurate monitoring of temperature and pressure is crucial in minimizing safety risks. Fiber optic sensors for temperature and pressure measurement have been widely successful in microwave assisted digestion applications due their immunity to electro magnetic field within the microwaves.