Air sampling system for a low-temperature space that enables removal of ice build-up within a sampling conduit

1. An air sampling system for a low-temperature space, the low-temperature space having a temperature of +4 degrees Celsius or below, the air sampling system including:

an air sampling pipe for passing sampling air to an air sampling device;

a sampling conduit having an entry port of a sampling point in the low-temperature space to an exit port outside the low-temperature space; the sampling conduit further having a longitudinal axis that extends from the entry port to the exit port, the air sampling pipe being connected to the exit port of the sampling conduit via a connection assembly having a restrictor for restricting flow of sampling air from the sampling conduit to the sampling pipe; wherein the connection assembly and restrictor are selectively removable from the exit port of the sampling conduit, enabling access in line with the longitudinal axis to a full cross-section of the sampling conduit from outside the low-temperature space whilst the sampling conduit remains in position, thereby to provide line of sight visual inspection from the exit port to the entry port and enable insertion of a rod into the exit port and sampling conduit for removal of ice build-up within the sampling conduit out through the entry port, wherein the sampling system further includes a bell or dome shaped nozzle at the entry port of the sampling conduit.

2. The air sampling system of claim 1 , wherein the sampling conduit has a cross-section that is substantially constant, or has a cross-section that increases in size from a downstream end thereof to an upstream end thereof.

3. The air sampling system of claim 1 , wherein the restrictor is part of a restriction fitting located at a mating portion or end of the connection assembly, the mating portion or end being connectable with and selectively removable from the exit port of the sampling conduit.

4. The air sampling system according to claim 1 , wherein the restrictor is a flow-restricting washer or orifice-plate.

5. The air sampling system according to claim 1 , wherein the restrictor acts as to limit flow through the sampling conduit to a pre-determined flow-rate.

6. The air sampling system according to claim 1 , wherein the restrictor is at a location that is warmer than and sufficiently far from the low-temperature space to prevent water vapor, sampled from the low-temperature space, from freezing on the restrictor.

7. The air sampling system of claim 1 , wherein the entry port is coated with silicone to prevent ice buildup.

8. The air sampling system according to claim 1 , wherein the sampling pipe has a plurality of connection assemblies and sampling conduits arranged at spaced intervals along the sampling pipe to draw air from the low-temperature space at a number of respective spaced sampling points.

9. An air sampling system for a low-temperature space, the low-temperature space having a temperature of +4 degrees Celsius or below, the air sampling system including

an air sampling pipe for passing sampling air to an air sampling device;

a sampling conduit extending from an entry port from the low-temperature space to outside the low-temperature space; the air sampling pipe being connected to an exit port of the sampling conduit via a connection assembly that is removable from the exit port, wherein the connection assembly has a restrictor that is selectively removable with the connection assembly from the sampling conduit, enabling access to the full cross-section of the sampling conduit from outside the low-temperature space while the sampling conduit remains in position, thereby to enable removal of ice build-up within the sampling conduit through the entry port;

wherein the sampling system further includes a bell or dome shaped nozzle at the entry port of the sampling conduit.