Abstract: A device for supplying cold gases to an NMR installation or analytical apparatus equipped with a measuring probe, with cold gases ensuring the cooling of the sample contained in the probe, but also its lift and rotation, the device including an insulated tank containing liquid gas at boiling point and in which are arranged exchangers through which gas streams to be cooled pass, these exchangers being connected to transfer lines channeling the cooled gases to the probe. The device also includes at least one additional exchanger that ensures a pre-cooling of the gas stream before it is channeled to the corresponding exchanger, with the or each additional exchanger coming in the form of a double-flow exchanger that is supplied either by the gaseous vapor produced by the boiling of the liquid gas in the tank or by the cold gas that is evacuated or that escapes at the probe.

Abstract: A heat exchanger delivers a pressurized dry gas stream cooled to an essentially constant temperature. The gas stream circulates in a coil with a functional part immersed in a liquid fraction of a second gas in a chamber of a corresponding container, whereby a portion of the wall of the container with the chamber contacts a liquid fraction of a third gas, providing a condensation surface for the second gas. The container containing the second pressurized gas is airtight. The condensation surface is dimensioned to allow absorption of a predetermined caloric power by the gas in the chamber without significant variation of temperature/pressure. Included is a monitored variable heater of the bath of the liquid fraction of the residual gas in the container, whereby total caloric power released by the circulating gas to be cooled and by the heater is constantly kept approximately equal to the specified caloric power.

Abstract: A heat exchanger delivers a pressurized dry gas stream cooled to an essentially constant temperature. The gas stream circulates in a coil with a functional part immersed in a liquid fraction of a second gas in a chamber of a corresponding container, whereby a portion of the wall of the container with the chamber contacts a liquid fraction of a third gas, providing a condensation surface for the second gas. The container containing the second pressurized gas is airtight. The condensation surface is dimensioned to allow absorption of a predetermined caloric power by the gas in the chamber without significant variation of temperature/pressure. Included is a monitored variable heater of the bath of the liquid fraction of the residual gas in the container, whereby total caloric power released by the circulating gas to be cooled and by the heater is constantly kept approximately equal to the specified caloric power.

Abstract: A cold junction compensation device for a thermocouple, comprising a thermostatically interface casing (1) receiving directly the wires (3, 3') of the thermocouple (2) and ensuring the interconnection of these latter with an extension cord (4). The interface casing (1) contains moreover a cold junction compensation circuit (5).