Abstract: In accordance with an embodiment of the invention, there is provided a method of warming a heat exchanger array of a very low temperature refrigeration system, the method comprising diverting at least a portion of refrigerant flow in the refrigeration system away from a refrigerant flow circuit used during very low temperature cooling operation of the refrigeration system, to effect warming of at least a portion of the heat exchanger array; and while diverting the at least a portion of refrigerant flow, preventing excessive refrigerant mass flow through a compressor of the refrigeration system.

Abstract: In accordance with an embodiment of the invention, there is provided a method of warming a heat exchanger array of a very low temperature refrigeration system, the method comprising diverting at least a portion of refrigerant flow in the refrigeration system away from a refrigerant flow circuit used during very low temperature cooling operation of the refrigeration system, to effect warming of at least a portion of the heat exchanger array; and while diverting the at least a portion of refrigerant flow, preventing excessive refrigerant mass flow through a compressor of the refrigeration system.

Abstract: In accordance with an embodiment of the invention, there is provided a method of warming a heat exchanger array of a very low temperature refrigeration system, the method comprising diverting at least a portion of refrigerant flow in the refrigeration system away from a refrigerant flow circuit used during very low temperature cooling operation of the refrigeration system, to effect warming of at least a portion of the heat exchanger array; and while diverting the at least a portion of refrigerant flow, preventing excessive refrigerant mass flow through a compressor of the refrigeration system.

Abstract: Atmospheric sampling system designed to minimize cross-contamination between successive samples acquired by a portable, or handheld, mass spectrometer. Techniques to reduce the overall sample load on portable mass spectrometers having limited pumping capacity, such as capture pumps. Techniques and methods employing simple manual devices and micro vacuum pumps for purging the inlet system of a mass spectrometer. Reduction of cross-contamination between successive samples, permitting a portable mass spectrometer to correctly associate sample positives with specific sample sites or individuals.

Abstract: Atmospheric sampling system designed to minimize cross-contamination between successive samples acquired by a portable, or handheld, mass spectrometer. Techniques to reduce the overall sample load on portable mass spectrometers having limited pumping capacity, such as capture pumps. Techniques and methods employing simple manual devices and micro vacuum pumps for purging the inlet system of a mass spectrometer. Reduction of cross-contamination between successive samples, permitting a portable mass spectrometer to correctly associate sample positives with specific sample sites or individuals.

Abstract: A portable or handheld mass spectrometer making use of a cryogenic pumping, ion pumping or getter pumping system. The portable mass spectrometer contains a cryopump, ion pump, or getter pump, and operates in conjunction with a fixed docking station. The docking station contains a backing pump to bring the mass spectrometer manifold down to operating pressure prior to being placed into portable operation using the cryopump, ion pump, or getter pump. The individual pumps may be operated either separately or simultaneously. This configuration permits the portable mass spectrometer module to be small, lightweight and rugged, and yet be easily and quickly recharged and regenerated for use in either a field or laboratory environment.

Abstract: In accordance with an embodiment of the invention, there is provided a method of warming a heat exchanger array of a very low temperature refrigeration system, the method comprising diverting at least a portion of refrigerant flow in the refrigeration system away from a refrigerant flow circuit used during very low temperature cooling operation of the refrigeration system, to effect warming of at least a portion of the heat exchanger array; and while diverting the at least a portion of refrigerant flow, preventing excessive refrigerant mass flow through a compressor of the refrigeration system.