US3714830A

US3714830A - Water sampling device

Info

Publication number: US3714830A
Application number: US00128395A
Authority: US
Inventors: R Keir
Original assignee: US Department of Navy
Current assignee: US Department of Navy
Priority date: 1971-03-26
Filing date: 1971-03-26
Publication date: 1973-02-06
Anticipated expiration: 1990-02-06

Abstract

A water sampling device capable of carrying a conventional laboratory-type flask container having a neck opening and a bottom opening with means for closing each of said openings to capture a water sample therein at a preselected water depth whereby the contamination problems of transferring the water sample to another container for laboratory analysis are avoided.

Description

United States Patent [191 Keir [4 1 Feb. 6, 1973 WATER SAMPLING DEVICE 3,339,417 9/1967 Richard; ..73/425.4 R Inventor: Robin S. Keir, San Diego, Calif. 3,097,532 7/1963 Brown et a1 ..73/425.4 R

[73] Assignee: The United States of America as Primary ExaminerS. Clement Swisher represented by the Secr ary f h Assistant ExaminerDaniel M. Yasich y Attorney-R. S. Sciascia, George J. Rubens and J. W. 22 Filed: March 26,1971

[2]] Appl. No.: 128,395 57 ACT A water sampling device capable of carrying a con- [52] US. Cl. ..73/425.4 R ventiona] laboratory type flask Container having [51] Int. Cl. ..G01n 1/10 neck opening and a bottom opening with means for [58] Field 01 Search ..73/425.4 R, 425, 421 R closing each of Said i g to capture a water ple therein at a preselected water depth whereby the [56} References cued contamination problems of transferring the water sam- UNITED STATES PATENTS pleodanother container for laboratory analysis are avoi e 2,223,598 12/1940 Brooks ..73/425.4 R 2,598,183 5/1952 Long et a1 ..73/425.4 R 2 Claims, 2 Drawing Figures FIG. 2

FIG. I

v INVENTOR. ROBIN s. KEIR ATTORNEYS WATER SAMPLING DEVICE STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION The invention relates to water sampling devices, and more particularly to a water sampling device which utilizes a conventional laboratory-type container that eliminates the need for transferring the water sample to another container for analysis purposes.

The determination of the amount of dissolved oxygen in sea water by the so-called Winkler method involves three basic steps, namely; the capture of the water sample at the preselected depth; the addition of chemicals to the sample; and the titration of the sample.

Previous methods of analysis require transfer of the water sample from one container to another between the several method steps described above. One of the most commonly used techniques is to transfer the sea water sample obtained by a Nansen bottle or similar seawater sampler by pipetting to a 300 ml reagent bottle in which the sample is pickled. The sample is then acidified and 50 ml aliquots are transferred to an Erlenmeyer flask for titration.

A modification of the above method provides for the transfer of the water samples from the Nansen bottle to Erlenmeyer flasks in which the subsequent pickling and titration steps are conducted. This procedure eliminates one of the pipetting transfer operations of the sample between the steps of pickling and titration. However there remains a practical problem involving the relative capacity of the 140 ml flask compared to that of a Nansen bottle of 1 liter. Since proper techniques require overflowing the flask by at least one volume to avoid a contaminated sample, no more than two flasks of sea water can be drawn from any one Nansen bottle in order to leave enough sea water for salinity analysis as well as other chemical analyses that may be desired.

There are several disadvantages of transferring the water sample between containers among the method steps described above. It is difficult to prevent the water sample from being exposed to air, the amount of exposure being heavily dependent on operator technique. Exposure of the sample to air presents two major sources of error, namely, loss of iodine gas owing to its appreciable volitility, and secondly, oxidation of acid solutions of iodine by oxygen of the air. Accepted procedure calls for a length of tubing to be connected to the petcock on the Nansen bottle and extended to the bottom of the laboratory flask. The petcock is opened slowly and the flask is filled, avoiding the creation of air bubbles. In practice, this result is difficult to achieve as air bubbles are very easily trapped in the transfer tubing. If air bubbles are present, the sample must be discarded and a new one redrawn--a condition the limited capacity of the Nansen bottle will not always allow. The magnitude of this error cannot be quantitatively estimated as it depends on the rate of transfer of oxygen gas from the air into solution in the sea water sample. This, in turn, depends on rate of filling of the sample bottle, turbulence of the inflowing sample, air bubbles trapped in the delivery tubing, i.e., conditions strongly dependent on operator skill. Such errors become quite significant when one is dealing with sea water samples having very low dissolved ox ygen concentrations.

SUMMARY OF THE INVENTION A water sampling device utilizing essentially a laboratory-type container preferably an ,Erlenmeyer flask, which has openings at the top and bottom thereof to permit the passage of water therethrough as the device is lowered to the desired depth. The flask is of a conventional design modified to the extent of cutting the opening in the base. Means are provided to close each opening at the selected water depth to capture a water sample at that level. When the device is raised to the surface the necessary laboratory analysis can be conducted in the sample container without the need for transferring the sample, minimizing the likelihood of contamination.

STATEMENT OF THE OBJECTS OF INVENTION A principal object of this invention is to provide a water sampling device utilizing a conventional container in which the sample can be captured and chemically analyzed, which will eliminate the need for transferring the water sample between separate containers. I

Another object of this invention is to provide a water sampling device which incorporates a conventional laboratory container.

Still further objects are to provide a water sampling device which is simple and inexpensive; which will ensure a more accurate laboratory analysis; and which will expedite the laboratory processes.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation of the water sampling device, partially in section, shown in an open condition such as during lowering; and

FIG. 2 is a top view of the water sampling device of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings where like reference numerals refer to similar parts throughout the figures, there is shown in FIGS. 1 and 2 a novel water sampling device 10 comprising basically a container 12 for capturing a sample of the sea water. Container 12, preferably, is a conventional polycarbonate clear plastic ml Erlenmeyer flask having a neck opening 14. The flask is modified only to the extent of cutting a 20 mm opening 16 in the enlarged base portion thereof. The oppositely disposing openings 14 and 16 in flask l2 enable the free flow of sea water therethrough as the device is being lowered to the selected depth to ensure that the water in the flask at all times is representative of the water outside the flask at all levels.

Neck opening 14 is adapted to be closed by a polyethylene stopper 18 secured at the lower end of a plunger 20 slidably mounted in a bar 22 secured to the top of a tube 24. Plunger 20 is provided with a handle 25 for manually unseating the stopper for insertion of chemicals into the flask during laboratory testing. The lower end of tube 24 is attached by a set of screws 26 to a bossed collar 28 secured around the neck of the flask.

A compression spring 30 is positioned between stopper 18 and bar 22 to bias the stopper to a seated position in the flask. Stopper 18 can be locked to an open position by a pin 32 which projects through both sides of tube 24 and through a horizontal opening in the stopper. One end of pin 32 has an integral eye portion 34 to which is attached a lanyard 36 for pulling the pin from the device to enable the stopper to be seated by spring action. Lanyard 36 can be tripped by the rotatable operation of a conventional Nansen bottle (not shown), to which the invention sampling device may be attached, or by any other mechanical action available on the particular lowering devices presently employed.

Base opening 16 in the flask is also provided with a closure means including a hinge 38 having one vertical leaf 40 fixedly strapped by spaced bands 42 to one side of flask 12. Another spring leaf 44 is rotatable having secured thereto a polyethylene stopper 46 adapted to be seated in opening 14 when leaf 44 is swung to a horizontal position. Spring leaf 44 is resiliently biased to its horizontal position by an elastic tubing 48 secured at its free end to a ring 49 attached to the end of leaf 44 and anchored at the other end to the flask, by a ring 50 through a guide 52. There is sufficient resiliency in tubing 48 when in a contracted condition to maintain stopper 46 seated in its closed position in the flask.

Hinge 38 is maintained in an open, vertical position shown in FIG. 1 against the tension of tubing 48 by a wire 54 attached to the free end of hinge leaf 44 at ring 56 and at the other end secured to a ring 58 through which pin 32 is normally threaded. When pin 32 is pulled free of tube 24 by lanyard 36, ring 58 is detached to unleash hinge 38 to its closed position with respect to the flask. It is obvious that the two closure means heretofore described need not be operated simultaneously nor triggered by the same means.

OPERATION In an oceanographic operation one or more of the invention water sampling devices may be secured piggy back, for example, to a conventional Nansen bottle or any other available water sampling lowering device.

Stoppers

18 and 46 are maintained in an unseated condition with respect to flask openings 14 and 16 to enable the sea water to flow freely therethrough until the desired d'epth is reached at which the sample is to be taken. When the Nansen bottle is flipped by the research personnel to record the temperature, etc., this movement may be utilized in the present invention to trigger lanyard 36 which simultaneously releases

stoppers

18 and 46 to close their respective openings and capture the desired water sample.

The Nansen bottle and the invention water sampling devices are simultaneously retrieved. Each flask 12 is transferred to the laboratory for the conduct of the chemical analyses. Plunger 20 can be lifted by hand to enable the required chemicals to be added to the flask and the stopper reseated. After acidification of the sample, the entire top closure mechanism including tube 24 is unscrewed and removed. A magnetic stirring bar can be inserted in the flask for titrating the sample.

After the laboratory processes are concluded flask 12 can be reassembled with the top closure mechanism and the device ready for reuse.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is: l. A water sampling device for lowering in a body of water comprising:

a conventional laboratory-type transparent container having an opening in a neck portion and an opening in the base portion thereof; I a closure member for each of the neck and base openings; separate resilient means for biasing each of said closure members to a closed position to block its respective opening; releasable restraining means for each of said resilient means; said restraining means maintaining each of said closure members to an open position to enable passage of the water through the container as it is being lowered in said body of water and operable to simultaneously release both closure members; whereby release of said restraining means will enable the closure members to block their respective,

openings by the action of its resilient means to trap a sample of water in the container at a predetermined level in the body of water. 2. The device of claim 1 wherein said container is an Erlenmeyer type flask.

l =l l

Claims

1. A water sampling device for lowering in a body of water comprising: a conventional laboratory-type transparent container having an opening in a neck portion and an opening in the base portion thereof; a closure member for each of the neck and base openings; separate resilient means for biasing each of said closure members to a closed position to block its respective opening; releasable restraining means for each of said resilient means; said restraining means maintaining each of said closure members to an open position to enable passage of the water through the container as it is being lowered in said body of water and operable to simultaneously release bOth closure members; whereby release of said restraining means will enable the closure members to block their respective openings by the action of its resilient means to trap a sample of water in the container at a predetermined level in the body of water.