In Microwave Pressure Digestion Systems, the samples in digestion equipment are heated directly by the absorption of microwave radiation. This allows for an extremely rapid simultaneous heating of typically 8-12 sample solutions which represents the actual microwave effect or advantage of microwave heating than the open heating method in hot plate. Once the set point temperature is reached, the decomposition reactions proceed at the same rate as in conventionally heated stainless steel pressure digestion vessels. Thus typical microwave digestions take merely 20-40 minutes. Microwave digestions are today employed for all types of samples and have therefore replaced stainless steel pressure digestion vessels in all applications other than the specialized applications. The strength of microwave digestion lies in its significantly higher sample through put resulting from the decrease in the duration of digestion. However, since this rapid heating is accompanied by an equally rapid pressure increase and possibly spontaneously induced exothermic reactions, the temperature and pressure progression of each sample must be continuously recorded and the microwave power must be regulated accordingly.