Liquid sampling device and method

A liquid sampling system comprising:

• a liquid sampling device to be lowered below ground level to a submerged sampling position in a body of liquid to be sampled and operable in a sample collecting mode and in a sample transfer mode while in said sampling position, said sampling device comprising sample collecting means including a sample collection chamber having a liquid inlet opening to the exterior of said device and a liquid outlet, sample collecting means operable in said sample collecting mode for effecting entrance of liquid in which the device is submerged into said collecting chamber through said inlet to collect within the chamber a liquid sample having a fixed volume, and sample transfer means operable in said sample transfer mode for evacuating a said liquid sample from said collection chamber through said outlet,
• sample receiving means to be located at a ground level sample receiving site remote from said sampling device,
• a sample transfer tube connecting said outlet of said sampling device to said sample receiving means, and
• control means to be located at said sample receiving site and connected to said sample collecting means and said sample transfer means for operating said sample collecting means and said sample transfer means to collect a liquid sample of said fixed volume in said sample collection chamber and then transfer the collected sample from said chamber to said remote sample receiving means, and wherein
• said chamber has normally upper and lower ends,
• said outlet opens to said chamber adjacent the lower end of the chamber,
• said sample collecting means includes a vent tube having one end connected to the upper end of said chamber and an opposite end to be located at said sample receiving site for venting said chamber to atmosphere during entrance of liquid into said chamber during said sample collection mode,
• said chamber evacuating means includes a pressurized gas source to be located at said sample receiving site and a gas tube having one end connected to said gas source and its opposite end connected to the upper end of said chamber for introducing pressurized gas into said chamber to expel a liquid sample from said chamber through said sample transfer tube,
• said sample receiving means comprises a removable sample container,
• said sample container comprises a septum bottle having a top opening and a septum closing said top opening,
• said sample receiving means further comprises a support, a pair of tubular needles mounted on said support including a first needle having open ends and a second having one end connected to said sample transfer tube for receiving liquid from said liquid sampling device and an opposite free end, and
• said needles puncture said septum for connecting said bottle to said liquid sampling device to receive a liquid sample from said liquid sampling device through one needle and vent the bottle to atmosphere through the other needle.

Liquid sampling apparatus for sampling liquid in a body of liquid and operable in a sample collecting mode and in a sample transfer mode, said sampling device comprising:

• a sampling device to be lowered to a submerged sampling position in said body of liquid and including a sample collection chamber having upper and lower ends, a liquid inlet opening into said chamber and to the exterior of said device for inflow of liquid from said body of liquid into said chamber through said inlet, a pressurized gas inlet opening into said chamber, and a liquid outlet opening into said chamber adjacent the lower end of the chamber and to the exterior of said device,
• sample collecting means for affecting inflow of liquid in which said sampling device is submerged into said collection chamber through said liquid inlet in said sample collecting mode to collect within the chamber a liquid sample having a certain fixed liquid volume and then closing said liquid inlet to block further liquid inflow into the chamber and liquid outflow from said chamber through said liquid inlet,
• sample transfer means for introducing a pressurized gas into said chamber through said gas inlet in said sample transfer mode and while said liquid inlet is closed to expel said liquid sample from said collection chamber through said outlet, and wherein
• said sampling device is devoid of any barrier blocking direct communication through said chamber between said gas inlet and said outlet, and said sample transfer means is operable to continue introducing pressurized gas into said chamber through said gas inlet drier expulsion of the entire liquid sample from the chamber through said outlet and without admission of additional liquid into the chamber, whereby Pressurized gas entering the chamber after expulsion of the liquid sample from the chamber exits the chamber through said outlet.

A liquid sampling system operable in a sample collecting mode and a sample transfer mode, said system comprising:

• a liquid sampling device to be submerged in a liquid to be sampled and including a sample collection chamber having upper and lower ends, a liquid inlet opening into said chamber and to the exterior of said device for inflow of liquid in which said device is submerged into said chamber through said inlet, a pressurized gas inlet opening into said chamber, and a liquid outlet opening into said chamber adjacent the lower end of the chamber and to the exterior of said device,
• sample receiving means to be located at a sample receiving site above the liquid in which said device is submerged,
• a sample transfer passage connecting said outlet to said sample receiving means,
• sample collecting means operable in said sample collecting mode for admitting liquid in which said device is submerged into said collection chamber through said liquid inlet to collect within the chamber a liquid sample having a certain fixed volume and then closing said inlet to block further liquid inflow into said chamber through said inlet and liquid outflow from said chamber through said liquid inlet,
• sample transfer means for introducing a pressurized gas into said chamber through said gas inlet in said sample transfer mode to expel the liquid sample from said collection chamber through said outlet and said transfer passage,
• control means to be located at said sample receiving site and connected to said sample collecting means and said sample transfer means for operating said collecting means and transfer means, and wherein
• said device is devoid of any barrier which blocks direct communication between said inlet and outlet through said chamber after expulsion of the entire liquid sample from the chamber through said outlet, and said sample transfer means is operable to continue introducing pressurized gas into said chamber after expulsion of the entire liquid sample from the chamber through said outlet and without admission of additional liquid into the chamber, whereby pressurized gas entering the chamber after expulsion of the liquid sample from the chamber exits the chamber through said outlet and said transfer passage,
• said transfer passage receives the liquid sample from said chamber through said outlet and forms the sample into a liquid column having a certain finite length which is directly proportional to the fixed volume of the sample, inversely proportional to the diameter of said transfer passage, and substantially less than the length of said transfer passage, and
• control means to be located at said sample receiving site and connected to said sample collecting means and said sample transfer means for operating said sample collecting means to collect a liquid sample of said fixed liquid volume within said chamber and then operating said sample transfer means without admission of more liquid into the chamber to introduce pressurized gas into the chamber through said gas inlet in a manner such that the gas first expels the collected sample of fixed volume from said chamber through said outlet into said transfer passage and then enters the transfer passage behind the liquid column formed by the liquid sample within said transfer passage and pushes the liquid column through the transfer passage to said sample receiving means.

A liquid sampling installation comprising:

• a body of liquid to be sampled located below ground level,
• liquid sampling apparatus operable in a sample collecting mode and a sample transfer mode and comprising a liquid sampling device including a sample collection chamber having upper and lower ends, means supporting said sampling device in a submerged sampling position in said liquid, a liquid inlet opening into said chamber and to the exterior of said device, a liquid outlet opening into said chamber adjacent the lower end of the chamber and to the exterior of said sampling device, sample receiving means located at a ground level sample receiving site, and a liquid transfer passage connecting said liquid outlet to said liquid receiving means, and wherein
• said sampling apparatus further comprises sample collecting means operable in said sample collecting mode for effecting inflow of said liquid into said collection chamber through said inlet to collect within said chamber a liquid sample having a certain fixed volume and then closing said inlet to block liquid inflow into and liquid outflow from said chamber through said inlet and sample transfer means for introducing a pressurized gas into said chamber in said sample transfer mode and while said inlet is closed to expel the liquid sample from said chamber through said outlet and said transfer passage, and said device is devoid of any barrier which blocks direct communication between said inlet and outlet through said chamber after the liquid sample has been expelled from said chamber,
• said sample transfer passage receives the liquid sample from said chamber through said outlet and forms the sample into a liquid column in said transfer passage having a certain finite length which is directly proportional to the fixed volume of the sample, inversely proportional to the diameter of said transfer passage, and substantially less than the length of said transfer passage, and
• said sampling apparatus further includes control means located at said sample receiving site and connected to said sample collecting means and said sample transfer means for first operating said sample collecting means to collect said liquid sample within said chamber and then close said liquid inlet and thereafter operating said sample transfer means while said inlet is closed and hence without admission of additional liquid into the chamber to introduce into the chamber a pressurized gas which first expels the collected sample of fixed volume from said chamber through said outlet into said transfer passage and then enters said transfer passage behind the liquid column formed by the liquid sample within said transfer passage and moves the liquid column through the transfer passage to said sample receiving means.

A liquid sampling method comprising the steps of:

• providing a liquid sampling apparatus including a sampling device containing a sample collection chamber having upper and lower ends for receiving a liquid sample of a certain fixed liquid volume, a liquid inlet opening to said chamber and to the exterior of said device, a liquid outlet opening to said chamber adjacent the lower end of the chamber and to the exterior of said device, a gas inlet opening to said chamber, and wherein said sampling device is devoid of any barrier blocking direct communication between said gas inlet and said liquid outlet, whereby gas entering said gas inlet may exit said chamber through said liquid outlet, a sample receiver, and a sample transfer passage connecting said outlet to said sample receiver having a diameter such that a liquid sample of said fixed liquid volume contained within said passage is formed into a liquid column having a certain finite length which is directly proportional to the said liquid volume, inversely proportional to said diameter, and substantially less than the length of said passage,
• placing said device in a submerged sampling position within a body of liquid to be sampled located below ground level,
• placing said sample receiver at a sample receiving site located above said liquid,
• admitting liquid into said chamber through said liquid inlet from
• said body of liquid to provide within said chamber a liquid sample of said certain fixed liquid volume and then closing said liquid inlet, and
• while said device occupies said submerged sampling position with said liquid inlet closed introducing into said chamber through said gas inlet a pressurized gas which first expels said fixed volume liquid sample from said chamber through said outlet into said sample transfer passage to form a liquid column of said certain length within the passage and then enters said passage behind said liquid column to move said liquid column through said passage to said sample receiver.