How does a laboratory microwave processor differ from a kitchen microwave oven?
The problem in establishing routine laboratory procedures using microwave technology has been the inadequacy of kitchen microwave ovens for laboratory use. Kitchen microwave ovens are rated by their maximum output power levels (e.g. 700 watts), and the only way of varying the amount of microwave energy entering the oven cavity is by switching the magnetron on and off over a period of time. All kitchen microwave ovens have preset cycle times, usually between 15 and 30 seconds. Therefore, if an oven with an output of 700 W and a cycle time of 30 seconds is required to operate at half its power (350 W), the magnetron is on for the first 15 seconds and off for the subsequent 15 seconds. In laboratory use, this often results in a cycle of heating and cooling that produces suboptimal and inconsistent results. At even lower power levels, the problem is exacerbated by the fact that the magnetron needs a second or so to warm up and begin emitting microwaves. For example, if 150 W of power is re
