Proportional sampling apparatus and method

Claim 3

A method according to claim 1 including cleaning said inlet by opening said inlet while said air is being introduced to said chamber and after said sample has been conveyed to said collection chamber.

Claim 4

A method according to claim 1 wherein the upstream flow assumes a level proportionate to its flow by obstructing the normal flow in said stream by inserting a weir plate having a weir notch therein into an opening of said primary measuring element to thereby cause an accumulation of liquid on the upstream side of the primary measuring element, wherein the sampling chamber is positioned with its inlet generally on the same level as the bottom of the weir notch, allowing a sample of the fluid to enter the sampling chamber at predetermined intervals, closing the inlet and pneumatically conveying the sample to said collection chamber.

Claim 5

A method according to claim 3 including the additional step of proportioning the configuration of the sampling chamber to the flow through the weir notch, to obtain a sample of a volume proportional to the flow as measured by the level of the stream upstream of the weir notch.

Claim 6

In a proportional sampling system for a flow stream, a damming unit adapted to be positioned in the flow stream to produce a change in the level of the flow stream upstream of the damming unit, a removable weir plate slidably guided in said damming unit and positioned in said damming unit during a sampling operation and having an opening therein of a predetermined configuration to produce a variation in the liquid level upstream of said weir plate during a sampling operation, a sampling chamber upstream of said damming unit and weir plate and having a volume proportional to the flow past said opening in said weir plate, an inlet to said sampling unit in a predetermined relation with respect to the bottom of said opening in said weir plate, an inlet valve in said inlet, means selectively operable to vent the top of said sampling chamber during the collecting of a sample therein, a control panel remote from said valve and flow stream, a source oF air under pressure, a selective connection from said source of air under pressure for supplying air under pressure to open and close said valve, another selective air connection leading from said control panel to said sampling chamber and providing air under pressure to said sampling chamber, a sample container remote from said sampling chamber, and an eductor leading from said sampling chamber for transferring a sample from said sampling chamber to said sample container by the pressure of air entering said sampling chamber.

Claim 7

In a proportional sampling system for a flow stream, a damming unit adapted to be positioned in the flow stream to produce a change in the level of the flow stream upstream of the damming unit, a removable weir plate slidably guided in said damming unit and positioned in said damming unit during a sampling operation and having an opening therein of a predetermined configuration to produce a variation in the liquid level upstream of said weir plate during a sampling operation, a sampling chamber upstream of said damming unit and weir plate and having a volume proportional to the flow past said opening in said weir plate, an inlet to said sampling unit in a predetermined relation with respect to the bottom of said opening in said weir plate, an inlet valve in said inlet, means selectively operable to vent the top of said sampling chamber during the collecting of a sample therein, a control panel remote from said valve and flow stream, a source oF air under pressure, a selective connection from said source of air under pressure for supplying air under pressure to open and close said valve, another selective air connection leading from said control panel to said sampling chamber and providing air under pressure to said sampling chamber, a sample container remote from said sampling chamber, and an eductor leading from said sampling chamber for transferring a sample from said sampling chamber to said sample container by the pressure of air entering said sampling chamber.

Claim 8

The sampling system of claim 5, wherein individual solenoid controlled valves are provided on said control panel, one valve controlling the flow of air from said source of air under pressure to said inlet valve to open said inlet valve to collect the sample, to close said inlet valve upon the collection of the sample, and the other valve being selectively operable to supply air to said sampling chamber under pressure to educt the sample to said container remote from said sampling chamber upon closing of said inlet valve.

Claim 9

The sampling system of claim 6, wherein said collection container is vented to atmosphere, and wherein said sampling chamber is vented to atmosphere through said collection chamber to accommodate the inlet of a sample to said sampling chamber upon opening of said valve.