METHOD AND APPARATUS FOR SUPPLYING SAMPLES FOR AUTOMATED ANALYSIS

• US 3,795,149 A
• Filed: 10/15/1971
• Issued: 03/05/1974
• Est. Priority Date: 10/15/1971
• Status: Expired due to Term

• Current Assignee: Technicon Instruments Corporation
• Original Assignee: Kent M. Negersmith, William H. Gillette, William J.C. Mccandless
• Inventors: Gillette, William H., McCandless, William J. C., Negersmith, Kent M.
• Primary Examiner(s): Swisher, S. Clement
• Application Number:
  US05/189,673
• Time in Patent Office: 872 Days
• Field of Search: 73/423A 210/391
• US Class Current: 73/863.24
• CPC Class Codes: G01N 35/1004 Cleaning sample transfer devices
• CPC Class Codes: G01N 35/1095 for supplying the samples to flow-through analysers for a specific analyser see relevant groups, e.g. under G01N15/00, G01N21/00, G01N27/00, G01N30/00, H01J49/00

Abstract

Liquid from a liquid sample container is flowed in automated analysis apparatus into a filter-equipped inlet end of a probe while the latter is immersed in the liquid, for transport of the sample to automated analysis. The probe is subsequently removed from the container and immersed in the liquid of a wash receptacle. Prior to immersion in another liquid sample, a fluid, other than sample, is flushed through the aforementioned filter in a reverse direction to cleanse it of particulate matter, the flushing being in timed relation to the movements of the probe.

Claims

1. Apparatus for supplying samples for automated analysis comprising:

a series of upwardly opening receptacles for different samples of a liquid, a dipping probe comprising a takeoff tube for the passage of a stream of liquid under a pressure differential from each one of said receptacles sequentially toward analysis, means to move said probe relatively between successive ones of said sample receptacles, said take-off tube having a filter adjacent a sample inlet thereof to catch and remove particulate matter from the sample liquid entering said sample take-off tube, said probe comprising a filter-flushing conduit extending axially along at least a portion of the length of said take-off tube, having an outlet upstream of said filter and in proximity thereto for reverse flushing of the latter, said flushing conduit having an inlet for flushing fluid, a source of flushing fluid for delivery under pressure, and means coupled to and between said source and said flushing conduit inlet and including a valve intermittently supplying flushing fluid to said flushing conduit to cleanse said filter of particulate matter, said valve being operated to deliver flushing fluid to said outlet after removal of said probe from one sample receptacle and before entry into the next following sample receptacle in timed relation to said probe movements.

2. Apparatus for supplying samples for automated analysis as defined in claim 1, further including:

a container for wash liquid, said probe moving means being operable to immerse the probe in the liquid of said wash liquid container between immersions in the samples of successive sample receptacles.

3. Apparatus for supplying samples for automated analysis as defined in claim 1, wherein:

the sample inlet pressure in said take-off tube is created by continuously operating suction means in communication with a sample outlet in said take-off tube upstream of said sample inlet thereof, and the take-off tube inlet flow rate is substantially less than the flow rate of said flushing fluid.

4. Apparatus for supplying samples for automated analysis as defined in claim 1, wherein:

said flushing conduit outlet is directed into said take-off tube in proximity to said sample inlet thereof.

5. Apparatus for supplying samples for automated analysis as defined in claim 1, wherein:

said sample filter is of cup form, and said sample inlet is formed in an end of said take-off tube, said tube end extending a distance into said filter cup, said flushing conduit being formed as a tube in which said take-off tube extends axially, said take-off tube having a substantially smaller outer diameter than the inner diameter of said flushing conduit.

6. Apparatus for supplying samples for automated analysis as defined in claim 1, wherein:

said flushing fluid is a gas.

7. Apparatus for supplying samples for automated analysis as defined in claim 2, further including regulated means for supplying said wash liquid to said wash receptacle, and controlled means for regulating the discharge of said wash fluid from said wash receptacle to waste, the filter being flushed in said wash receptacle.

8. Apparatus for supplying samples for automated analysis as defined in claim 2, wherein:

said valve is operated in timed relation to said probe movements to flow said flushing fluid through said filter when said probe is immersed in the liquid of said wash receptacle.

11. Apparatus for supplying samples for automated analysis as defined in claim 1, wherein:

said flushing conduit is formed as a tube and has said outlet thereof directed into said take-off tube.

12. Apparatus for supplying samples for automated analysis as defined in claim 11, wherein:

said sample inlet is formed in an end of said sample take-off tube, and said sample filter is of cup-shape and extends over said sample inlet.

13. Apparatus for supplying samples for automated analysis as defined in claim 12, wherein:

said sample take-off tube extends axially within said flushing tube and has an outer diameter less than the inner diameter of said flushing tube to form a flushing fluid passageway between said tubes.

9. A method for supplying samples for automated analysis employing a filter and a series of upwardly open receptaCles for different samples of a liquid, comprising:

flowing under pressure a stream of liquid from each one of said sample receptacles sequentially toward analysis in a take-off tube while filtering with said filter the sample liquid as it enters said tube to remove particulate matter, moving said take-off tube relatively between successive ones of said sample receptacles for immersion in the samples thereof, and introducing on plural occasions a flushing fluid other than said sample upstream of and in proximity to said filter in a direction opposite the direction of sample flow to remove particulate matter from said filter, after removal of said take-off tube from one sample receptacle and before entry into the next following sample receptacle.

10. A method for supplying samples for automated analysis as defined in claim 9, wherein:

a receptacle of wash liquid is provided, said take-off tube being moved for immersion in the liquid of said wash receptacle between movements of said take-off tube into successive ones of said sample receptacles, said flushing fluid comprising a gas, said flushing taking place on one of said occasions in the liquid of said wash receptacle and on another occasion, when said take-off tube is not immersed, immediately prior to immersion of the take-off tube in the next sample.