Compressed breathing air sampling device

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG.
1, a sampling apparatus 10 includes a flow control member 12 amd a sample collector 14.
The flow control member 12 is connected to the sample collector 14 by a pair of tubes 16, 18.
The tube 16 is connected to the inlet of a flow meter 20 mounted on a vertical wall 22 of a support plinth 24.
The outlet to the flow meter terminates in a terminal member 26 mounted on the horizontal face 28 of the plinth 24.
The tube 18 is connected to a filter assembly 30 mounted on the horizontal face 28 and having an output connected to a flow meter 32.
The outlet from the flowmeter 32 is vented to atmosphere through a conduit 34.
The flowmeter 20 includes a flow adjustment device 36 which controls the flow through the tube 16.
The flow passing through the tube is indicated on a scale 38 mounted on the flow meter in known fashion.
Similarly the flow meter 32 includes a flow regulating device 40 which controls the flow through the tube 18.
The flow regulating device 40 is arranged so that it cannot completely close the passage of gas through the tube 18 to prevent pressurization of the filter assembly 30.
The flow control member 12 is best seen in FIG.
2 and includes a body 42 with a longitudinal blind bore 44 extending from an outlet nozzle 46.
The nozzle 46 is provided with a series of circumferential serrations 48 to assist in retaining the tube 18 which is connected to the nozzle 46 in location.
The bore 44 is intercepted by an outlet conduit 50 which is connected through an elbow 52 (FIG.
1) to the tube 16.
The bore 44 is also intercepted by a pressure relief conduit (not shown) which connects to a safety relief valve 54 (FIG.
1) to prevent overpressurization of the tubes 16 and 18.
Admission of gas to the bore 44 is provided by an inlet nozzle generally designated 56.
The nozzle includes a circular recess 58 which is relieved at its peripheral portion 60 to provide a seat for an O ring 62.
The dimensions of the recess 58 are chosen to match the standard dimensions of a compressed gas filling yoke commonly associated with pressurized sources of compressed gas