US Patent 7829828 Microwave assisted chemical synthesis instrument with controlled pressure release

An instrument for carrying out controlled microwave assisted chemical processes, and that is particularly useful for handling relatively small samples. The instrument includes a microwave-transparent reaction vessel with an open mouth, a pressure-resistant seal on the mouth of the vessel, and a needle, portions of which penetrate the seal with a first end of the needle and provide fluid communication into the vessel. A pressure transducer is at the opposite end of the needle and in fluid communication with the interior of the vessel through the needle. The instrument defines a pressure control flow path from a portion of the needle outside of the vessel to a fluid port, the flow path being in communication with the needle, the interior of the vessel and the transducer. A controllable pressure release valve for the flow path is associated with the port.