Abstract:
A fluid sampling system for sampling the contents of a container of fluid includes an elongate hollow sampling conduit extending between a first end for withdrawing the fluid from the container and a second end for returning the fluid to the container, pump means for circulating the fluid between the container and the sampling conduit, a sample probe having a tip extending into the sampling conduit so as to contact the fluid within the sampling conduit, and a controller unit for controlling flow of the fluid within the sampling conduit and monitoring the properties of interest of the fluid within the sampling conduit via signals received from the sample probe. The present invention also provides an in-line pH probe.

Description:
This application is a filing under 35 U.S.C. 371 of international application number PCT/US2008/056926, filed Mar. 14, 2008, which claims priority to U.S. application No. 60/894,943 filed Mar. 15, 2007, the entire disclosure of which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to fluid sampling systems. More specifically, the present invention relates to a closed-loop fluid sampling systems having an in-line probe. 
     BACKGROUND OF THE INVENTION 
     Producing radioactive Thallium products for pharmaceutical use, like other hazardous or valuable materials, is a fairly complex process with many steps and requirements. One requirement during production is that pH samples of the product have to be tested very often. A typical day may require four to ten pH tests. Each test requires a two-point calibration of the probe, along with a wash and dry of the probe before and between taking these calibration measurements. A two-point calibration requires that the pH probe be cleaned and dried, followed by a dip in a first buffer fluid, setting the probe electronics to the pH level of the first buffer; a second cleaning and drying, followed by a dip in a second buffer, and setting the probe electronics to reflect the second buffer level. As a result, a typical day of thallium production may require many buffer dips, cleans, and dries per day. Furthermore, performing these tests manually, with paper testing, dipping of the probe into fluids such as buffer  4 , buffer  7 , and water for injection, and subsequent towel drying the of the probe is very manually intensive work, time consuming, and also results in shutting down the process as well as risking contamination or exposure to the human operator. 
     Additionally, testing the pH is a destructive test and waste of the sampled fluid because it requires fluid to be removed from the fluid container and tested for its pH level. Should the pH level be too high or too low, a pH additive is added to the sample. Testing is repeated until the sample fluid reads as being at the desired pH level. All of the fluid tested is lost or wasted since it will not be added back into original sample container but disposed of as waste during the subsequent cleaning of the probe. Even though the amounts of fluid may seem to be small, for particularly hazardous or valuable fluids, such losses can be quite costly due to the loss of product or even just the cost of handing and disposing of a radioactive or biologically sensitive material. 
     In order to eliminate the loss or exposure of the hazardous fluid, there is a need a for a closed-loop conduit system incorporating an in-line probe. While probes for manually dipping into a sample well are available, no probes are provided in an assembly for use in a closed-loop system. In order to calibrate or clean the probe, the probe must be manually transferred from the sample well to a cleaning or calibration station. Valuable or hazardous product on the probe may be lost or exposed to the atmosphere, endangering the surrounding environment, the handler, or the product itself. 
     There is therefore a need for a probe which may be provided integrally to a fluid handling or dispense system. There is also a need for a fluid sampling system with an in-line probe. The in-line probe should be able to be calibrated and cleaned without requiring disassembly of the probe from the system. Additionally, there is a need for a fluid sampling system which allows the monitoring and adjustment of the pH level of the fluid conducted within. 
     SUMMARY OF THE INVENTION 
     In view of the needs of the prior art, the present invention provides a fluid sampling probe for use in a fluid handling system. The probe include an elongate conduit segment having a conduit body defining first and second opposed open ends and an elongate fluid passageway extending in fluid communication therebetween. The conduit body further includes a probe aperture in fluid communication with the fluid passageway. A fluid sampling probe having an elongate probe body is supported in the probe aperture so that a first end of the probe extends into the fluid passageway. 
     The present invention also provides a fluid sampling system for sampling the contents of a source of fluid having an elongate hollow sampling conduit extending between a first end for withdrawing the fluid from the container and a second end for returning the fluid to the container. The sampling system also includes pump means for circulating the fluid between the container and the sampling conduit and a sample probe having a tip extending into the sampling conduit so as to contact the fluid within the sampling conduit. The sampling system further includes at least one of a calibration fluid source, a wash fluid source, and an additive source. A controller unit controls flow of the fluid to and from the container as well as flow from any calibration fluid source, wash fluid source or additive source so included in the sampling system while also being able to monitor the properties of interest of the fluid within the sampling conduit via signals received from said sample probe. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a schematic of the fluid handling system of the present invention. 
         FIG. 2  depicts an in-line sampling probe of the present invention. 
         FIG. 3  depicts the pH-adjusting sub-systems and the calibration sub-systems of the fluid handling system of the present invention. 
         FIG. 4  depicts a valve used in the fluid handling system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to  FIG. 1 , the present invention provides a fluid sampling system  10  which is able to continuously monitor and adjust a fluid&#39;s characteristics without the need for manual exposure or intervention. The present invention is able to introduce a hazardous material into a closed loop system and containing the waste, maintaining separation of hazardous material from the environment, protecting the environment and the material from each other. There is no need to break down system  10  for maintenance, as it is self-contained to clean itself between uses. Additionally, the present invention allows for non-destructive testing of the fluid product. Some fluids, such as radioactive thallium, are very expensive to manufacture, the present invention saves fluid and thus reduces costs of lost product. Furthermore, while the current sampling process for a radioactive product takes over one hour to complete, the present invention is able complete all steps within about 5 minutes. Fluid sampling system  10  includes a touch-screen monitor  752  for interfacing between an operator and a programmable logic controller  750 . Controller  750  controls each of the mechanical and electro-mechanical components of the present invention. 
     Fluid sampling system  10  includes a hollow conduit  12  comprised of various conduit segments  12   a - l  extending between a first open free end  14  and a second open free end  16  within the cavity  18  of a product collection bottle  20 . Conduit  12  provides an interruptable circular flow path  15  beginning and ending at cavity  18  of product collection container  20 . Container  20  is typically a 100 mL product collection bottle which holds a fluid of interest  22  within its cavity  18 . By way of illustration and not of limitation, fluid  22  may be radioactive thallium, but it is further contemplated that system  10  may be used for handling a wide variety of hazardous materials or for materials which should be protected from the environment. Free ends  14  and  16  of conduit  12  desirably extend into cavity  18  so as to be in sealed fluid communication therewith, such that fluid  22  is isolated from the outside environment. Typically container  20  includes a cap or stopper  19  which permits ends  14  and  16  of conduit  12  to extend therethrough so as to place cavity  18  in isolated fluid communication with flow path  15 . 
     Conduit  12  thus provides a closed circuit loop for the flow of fluid  22  into first end  14  of conduit segment  12   a , through flow path  15 , and out second end  16  back into cavity  18 . While flow path  15  is defined by the various conduit segments, and extends through the provided valves and probe housing, its typical flow direction is depicted by arrows  15  in  FIG. 1 . A pH probe  24  is extends into passageway  15  so as to provide an in-line probe for determining the pH level of the fluid flowing therepast. Conduit segments  12   a - k  extend in sealed fluid communication between a series of valves  30   a - i , described further hereinbelow, provided along flow path  15 . 
     Additional valves  40   a - c  regulate the provision of product fluids from supply ports  44   a - c , respectively, to be introduced into container  20  through a conduit  42  including conduit segments  42   a - e . Conduit supply ports  44   a - c  are provided in fluid communication with three distinct sources of product fluid, not shown. While shown in  FIG. 1 , valves  40   a - c  and conduit segments  42   a - d  are not central to the present invention. Any system for supplying a fluid of interest to valve  50   c  may be incorporated into the system of the present invention. Valves  50   a - b  regulate the provision of clean air and saline through conduits  12  and conduit segments  42   e  and  52   a - e  for the purpose of cleaning and drying flowpath  15  and conduit segment  42   e  between runs of filling successive containers  20  with a product fluid. Clean air, or any other suitable drying agent, is provided to valve  50   a  through a clean air port  54  which is in fluid communication with a source of clean air, not shown. Saline, or any other suitable washing fluid, is provided from a saline container  56  to valve  50   a  through conduit  52   b.    
     Conduit  12  desirably incorporates a total length of approximately 2 feet of 1/16″ to ⅛″ inner diameter of tubing such that the total volume of flow path  15  is less than about 3 ml. It is further contemplated that conduit  12  may be made from polypropylene, tygon or any other suitable material for pharmaceutical preparation. 
     In-line probe  24  is desirably provided extending though a segment of stainless steel tubing which has been incorporated into the fluid circuit. In-line probe  24  is provided to detect the pH level of fluid  22  as it flows through conduit  12 . As shown in  FIG. 2 , in-line probe  24  includes a housing  70  defining a passageway  72  therethrough for receiving free ends of conduit segments  12   h  and  12   i  therein so as to be placed in fluid communication with, and thus form part of, flow path  15 . Housing  70  is desirably a segment of stainless steel conduit. Housing  70  also defines a probe aperture  74  extending in fluid communication between passageway  72  and the exterior of housing  12 . An elongate probe body  76  extends through aperture  74  so that its sampling tip  78  desirably extends into about the center of passageway  72 . The opposing end  80  of probe body  76  is positioned in electronic communication with a pH meter  25  which determines the pH level of fluid  22  as it flows therepast. In-line probe  24  has been constructed using a probe body provided by Fisher Scientific. In the past, such probe bodies were used for manually dipping into a sample container having a sample of a product fluid therein. The present invention incorporates the probe body into a fluid sampling and dispense system as described herein. While in-line probe  24  is shown and described for measuring pH of a fluid of interest, one of skill in the art will recognize that other probe bodies may be incorporated into a sampling system of the present invention for detecting, by way of illustration and not of limitation, purity, concentration, color, or turbidity. 
     Probe  24  provides a signal indicative of the measured pH level of the fluid  22  flowing therepast. While the present invention is shown and described as providing a system for measuring and adjusting the pH-level of the fluid, other fluid characteristics are also contemplated as being measured by probe  24 . 
     Referring again to  FIG. 1 , fluid sampling system  10  desirably provides a vacuum trap  90  provided in isolatable fluid communication between valve  30   a  and a vacuum source  92 . Vacuum trap  90  is typically a bottle having a stopper  94  in its mouth  96 . A vacuum conduit  100  having vacuum conduit segments  100   a - c  extending between valve  30   a  and vacuum source  92 . Stopper  94  accommodates segment  100   a  and  100   b  therethrough. Valve  102  isolates vacuum source  92  from vacuum trap  90 . Providing vacuum trap  90  ensures that any radioactive or other environmentally-sensitive fluid drawn to product collection bottle  20  is contained prior to reaching vacuum source  92 . 
     Valve  30   g  is connected to a waste collection container  110  via a waste conduit  112 . A waste vent conduit  114  extends from waste collection container  110 . Waste collection container  110  is provided to collect and vent the saline and clean air, respectively, after each has been sufficiently circulated through conduits  12 ,  42   e , and  52   d - e  between dispensings to a respective product collection bottle  20 . Waste vent conduit  114  is desirably placed in fluid communication with a means for withdrawing waste fluid from container  110 . The withdrawing means may include, for purposes of illustration and not of limitation, a peristaltic pump, a syringe pump, a vacuum source, or even a gravity siphon. 
     Fluid sampling system  10  also includes a fluid pump  120  placed in fluid communication with flow path  15  between conduit segments  12   c  and  12   d . Pump  120  is desirably a peristaltic pump. Between pump  120  and in-line probe  24 , fluid sampling system  10  provides for four separate fluid inputs at valves  30   c - f . Valve  30   c  provides for the input into flow path  15  of a high pH fluid, such as NaOH. Valve  30   d  provides for the input into flow path  15  of a low pH fluid, such as HCl. Valves  30   c  and  30   d  thus provide for the adjustment of the pH level of fluid  22  in response to the reading provided by in-line probe  24 . Valve  30   e  provides for the input into fluid flow path  15  of a solution of buffer  4 , i.e. a solution having a known low pH level. Valve  30   f , conversely, provides for the input into fluid flow path  15  of a solution of buffer  7 , a solution having a known high pH level. Valves  30   e  and  30   f  provide for the calibration of in-line probe  24  prior to drawing fluid  22  into container  20 . Saline solution and clean air will desirably circulate through flow path  15  between the calibration runs and the pH sampling runs for fluid  22 . 
     With additional reference to  FIG. 3 , valve  30   c  selectably connects conduit segment  12   e  with a high-pH additive system  130 . System  130  desirably provides an additive such as NaOH into fluidpath  15  so as to raise the pH level of the fluid being analyzed. High-pH additive system  130  includes a flow control valve  132 , a syringe pump  134 , a first conduit  136  extending between valve  132  and an input port  138 , and a second conduit  140  extending between valves  132  and  30   c . Input port  138  is desirably placed in fluid communication with a bulk source of high-pH additive (not shown). A check valve  142  is provided along conduit  136  to prevent flow from traveling from valve  132  towards input port  138 . Syringe pump  134  is an electronically-controlled syringe device having an elongate barrel  146  defining a barrel cavity  147  and supporting a movable piston  148  therein. An elongate piston rod  150  extends between piston  148  and a free end  152  which is engaged for urging piston  148  in an extended or retracted direction through barrel cavity  147 . Presently, a 50 cc syringe manufactured by Becton-Dickinson is employed for syringe pump  134 . Barrel  146  also includes a luer-lock tip  154  defining a flow port  156  in fluid communication between barrel cavity  147  and flow control valve  132 . Suitable connection between tip  154  and valve  132  may be provided to extend the separation between the two while maintaining fluid integrity therebetween. Flow control valve  132  provides for selectable fluid flow from a high pH bulk source to barrel cavity  147 , and from barrel cavity  147  to valve  30   c . As piston  148  is drawn in a retracted direction, flow control valve  132  is set to allow the high pH fluid to be drawn through input port  138  into barrel cavity  147 . When piston  148  is extended towards flow port  156 , valves  132  and  30   c  will be set to allow the high pH fluid to be injected into flow path  15 . 
     Valve  30   d  selectably connects conduit segment  12   f  with a low-pH additive system  230 . System  430  desirably provides an additive such as HCl so as to lower the pH level of the fluid in fluidpath  15 . Low-pH additive system  230  includes a flow control valve  232 , a syringe pump  234 , a first conduit  236  extending between valve  232  and an input port  238 , and a second conduit  240  extending between valve  232  and  30   d . Input port  238  is desirably placed in fluid communication with a bulk source of low-pH additive (not shown). A check valve  242  is provided along conduit  236  to prevent flow from traveling from valve  232  towards input port  238 . Syringe pump  234  is an electronically-controlled syringe device having an elongate barrel  246  defining a barrel cavity  247  and supporting a movable piston  248  therein. An elongate piston rod  250  extends between piston  248  and a free end  252  which is engaged for urging piston  248  in an extended or refracted direction through barrel cavity  247 . Presently, a 50 cc syringe manufactured by Becton-Dickinson is employed for syringe pump  234 . Barrel  246  also includes a luer-lock tip  254  defining a flow port  256  in fluid communication between barrel cavity  247  and flow control valve  232 . Suitable connection between tip  254  and valve  232  may be provided to extend the separation between the two while maintaining fluid integrity therebetween. Flow control valve  232  provides for selectable fluid flow from a low pH bulk source to barrel cavity  247 , and from barrel cavity  247  to valve  30   d . As piston  248  is drawn in a refracted direction, flow control valve  232  is set to allow the low pH fluid to be drawn through input port  238  into barrel cavity  247 . When piston  248  is extended towards flow port  256 , valves  232  and  30   d  will be set to allow the low pH fluid to be injected into flow path  15 . 
     Still referring to  FIG. 3 , valve  30   e  selectably connects conduit segment  12   g  with a low-buffer additive system  330 . The low-buffer additive has a known, relatively low, pH level and may be run through fluidpath  15  in order to calibrate probe  24 . Low-buffer additive system  330  includes a flow control valve  332 , a syringe pump  334 , a first conduit  336  extending between valve  332  and an input port  338 , and a second conduit  340  extending between valve  332  and  30   e . Input port  338  is desirably placed in fluid communication with a bulk source of Low-buffer additive (not shown). A check valve  342  is provided along conduit  336  to prevent flow from traveling from valve  332  towards input port  338 . Syringe pump  334  is an electronically-controlled syringe device having an elongate barrel  346  defining a barrel cavity  347  and supporting a movable piston  348  therein. An elongate piston rod  350  extends between piston  348  and a free end  352  which is engaged for urging piston  348  in an extended or retracted direction through barrel cavity  347 . Presently, a 50 cc syringe manufactured by Becton-Dickinson is employed for syringe pump  334 . Barrel  346  also includes a luer-lock tip  354  defining a flow port  356  in fluid communication between barrel cavity  347  and flow control valve  332 . Suitable connection between tip  354  and valve  332  may be provided to extend the separation between the two while maintaining fluid integrity therebetween. Flow control valve  332  provides for selectable fluid flow from a low-buffer bulk source to barrel cavity  347 , and from barrel cavity  347  to valve  30   e . As piston  348  is drawn in a retracted direction, flow control valve  332  is set to allow the low-buffer fluid to be drawn through input port  338  into barrel cavity  347 . When piston  348  is extended towards flow port  356 , valves  332  and  30   e  will be set to allow the low-buffer fluid to be injected into flow path  15 . 
     Valve  30   f  selectably connects conduit segment  12   h  with a high-buffer additive system  430 . The high-buffer additive has a known, relatively high, pH level and may be run through fluidpath  15  in order to calibrate probe  24 . High-buffer additive system  430  includes a flow control valve  432 , a syringe pump  434 , a first conduit  436  extending between valve  432  and an input port  438 , and a second conduit  440  extending between valve  432  and  30   f . Input port  438  is desirably placed in fluid communication with a bulk source of high-buffer additive (not shown). A check valve  442  is provided along conduit  436  to prevent flow from traveling from valve  432  towards input port  438 . Syringe pump  434  is an electronically-controlled syringe device having an elongate barrel  446  defining a barrel cavity  447  and supporting a movable piston  448  therein. An elongate piston rod  450  extends between piston  448  and a free end  452  which is engaged for urging piston  448  in an extended or retracted direction through barrel cavity  447 . Presently, a 50 cc syringe manufactured by Becton-Dickinson is employed for syringe pump  434 . Barrel  446  also includes a luer-lock tip  454  defining a flow port  456  in fluid communication between barrel cavity  447  and flow control valve  432 . Suitable connection between tip  454  and valve  432  may be provided to extend the separation between the two while maintaining fluid integrity therebetween. Flow control valve  432  provides for selectable fluid flow from a high-buffer bulk source to barrel cavity  447 , and from barrel cavity  447  to valve  30   f . As piston  448  is drawn in a retracted direction, flow control valve  432  is set to allow the high-buffer fluid to be drawn through input port  438  into barrel cavity  447 . When piston  448  is extended towards flow port  456 , valves  432  and  30   f  will be set to allow the high-buffer fluid to be injected into flow path  15 . 
     Each of the valves and pumps of the present invention are controlled through a programmable logic controller  750  which is itself desirably receives operator inputs through a touchscreen monitor  752 . A Controllogix processor having 3.5 Megabytes of nonvolatile memory sold by Allen-Bradley Co. was used in constructing the present invention. Monitor  752  was a an Allen-Bradley Co. Panelview Plus 1500 304×228 mm, 1024×768 18-Bit color graphics, batter backed clock timestamps, with extended 128 MB/128 MB Ethernet. Controller  750  desirably provides command and control of each valve and pump through a standard RS-232 interface, although any manner of control, such as either wireless or hard-wired, of each of the valves and pumps is further contemplated. The pH meter  25  incorporated was manufactured by Cole-Parmer as the Orion Perphect Model 370, 110 VAX, including electrode part #58820-59, and AC adaptor, PS232 output. Additionally, pH meter  25  may provide for wireless or hard-wired interface to monitor  752  or simply provide its own display of the measured pH of a fluid in fluidpath  15  in an operator-convenient location. It is further contemplated that data from meter  25  may be printed out or sent straight to an electronic record system which records and stores the data. 
     Additionally, while pumps  134 ,  234 ,  334 , and  434  are described as being syringe pumps, the present invention contemplates that any pump which provides for high precision microdispense (with minimum dispenses of about 0.05 ml) may be employed. Each such pump typically has its own controller which interfaces with controller  750  (typically a standard interface such as an RS232 connection) and is a solid state remotely programmable pump. These pumps are desirably either peristaltic or syringe pumps. 
     The valves are generally incorporated to provide another fluid or receptacle in selectable fluid communication with passageway  15 . “Selectable fluid communication” describes the valves ability to place one of two selectable input lines into fluid communication with a third fluid line. 
     Each valve is desirably a biochem valve with either a Teflon or stainless steel flow path. The valves are desirably operable by a controllable solenoid although it is further contemplated that each valve may be operated manually. The 3-way valves used to construct system  10  were manufactured by ASCO and include Teflon wetted parts, ¼-28 ports, 0.062 orifice, max pressure of 30 psi, 24 volt DC, 5.3 watts. 
     System  10  provides thus provides a closed loop system for measuring the pH of a fluid of interest. System  10  is able to wash and dry its fluid-handling conduit between successive runs. Additionally, system  10  provides a closed loop system for calibrating probe  24 . 
     First Calibration 
     Starting with conduit segments  12   h - i  in a clean and dry condition, system  10  closes the appropriate valves to isolate these segments so as to allow high-buffer fluid to be dispensed directly from pump  434 , through in-line probe  24  and directly into waste container  110 . Controller  110 , knowing the pH level of the high-buffer fluid can correct or interpret the signal from probe  24  so as to read the correct pH level of the high-buffer fluid. Valve  30   f  will isolate conduit  440  from fluidpath  15 . Valves  50   a ,  50   b  and  30   b - g  will then cooperate to serially provide first saline solution and then clean air to and through conduit segments  52   c ,  52   d , and  12   c - i  so as to clean and dry conduit segments  12   h  and  12   i.    
     Second Calibration 
     Then, with conduit segments  12   g - i  in a clean and dry condition, system  10  closes the appropriate valves to isolate these segments so as to allow low-buffer fluid to be dispensed directly from pump  334 , through in-line probe  24  and directly into waste container  110 . Controller  110 , knowing the pH level of the low-buffer fluid can correct or interpret the signal from probe  24  so as to read the correct pH level of the low-buffer fluid. Valve  30   e  will then isolate conduit  340  from fluidpath  15 . Valves  50   a ,  50   b  and  30   b - g  will then cooperate to serially provide first saline solution and then clean air to and through conduit segments  52   c ,  52   d , and  12   c - i  so as to clean and dry conduit segments  12   g - i.    
     With system  10  thus calibrated to read the correct pH of the fluid flowing through in-line probe  24 , system  10  is ready to read and adjust the pH level of the fluid. 
     Introduction of Fluid 
     Fluid  22  is introduced into system  10  through valve  50   c . A check valve  55  is provided to ensure one-way flow of fluid. Additionally, a 0.22 micron filter  57  is provided to capture particulate prior to entering system  10 . The actual plumbing between source ports  44   a - c  and valve  50   c  is not considered salient to the instant invention. The present invention contemplates that each of valves  40   a - c  may be provided in selectable fluid communication with a wash and dry fluid source when in the closed position so as to wash and clean the fluid line  42   d  between the respective valve  40   a - c  and valve  50   c . Controller  750  operates the appropriate valve  40   a - c  and valves  50   c ,  30   h ,  30   i ,  30   a , and  103  with vacuum source  92  so as to draw fluid from the appropriate source into cavity  18  of container  20 . It is contemplated that for this filling process, free end  14  of conduit segment  12   a  may be retracted away from the bottom of container cavity  18  so as not to draw fluid  22  towards vacuum trap  90  before the requisite amount of fluid reaches container  20 . 
     Adjusting pH of Sample Fluid 
     Once container  20  is filled with the appropriate fluid  22  of interest, system  10  is then able to perform a closed loop analysis and adjustment of the fluid&#39;s pH level. System  10  closes the appropriate valves to place cavity  18  in isolated fluid communication with fluidpath  15 . Pump  120  then circulates fluid  22  through fluidpath  15  so as to pass through in-line probe  24  where its pH is measured. The fluid is thus measured dynamically as the fluid circulates. If the measured pH level falls outside the prescribed level or range for fluid  22 , pump  120  will pause fluid flow. Then the appropriate valve  30   c  or  30   d  will close so as allow the appropriate pH additive system  130  or  230  to dispense a metered amount of the respective additive fluid. Should fluid  22  need a higher pH level, additive system  130  will dispense into conduit segment  12   e . Should fluid  22  need a lower pH level, additive system  230  will dispense into conduit segment  12   f . After the appropriate additive system has provided an adjusting aliquot into fluidpath  15 , its valve  30   c  or  30   d  will then re-open so as to re-establish fluid flowpath  15  in fluid communication with cavity  18  of container  20 . Pump  120  will then circulate fluid  22  through fluidpath  15  multiple times so as to ensure mixing of the additive and fluid  22  into a homogenous mixture. After a predetermined time of circulating, system  10  will again read the pH level at probe  24 . System  10  will again take corrective action, if necessary. Once system  10  reads an acceptable pH level for fluid  22 , container  20  may be removed from system  10 . 
     Post-Measurement Washing 
     A second container  20  may then be placed in fluid communication with fluidpath  15 . Any of the original fluid  22  still retained in fluidpath  15  will first need to be removed. System  10  cleans conduit segments  12   l  and  12   a  by closing valves  30   i ,  30   a  and  102  to draw the fluid entrained within segments  12   l  and  12   a  into container  90 . Then, vacuum source  92  operates to draw saline fluid from container  56  through segments  52   b ,  52   c ,  52   e ,  42   c ,  12   k , and  12   l  into cavity  18  of new container  20  and out through segments  12   a  and  100   a  into container  90 . As the volumes of the containers are much higher than the total volume of all the conduits, system  10  can ensure that the entrapped fluid  22  will not be drawn out line  100   c  to vacuum source  92 . Clean air will then be provided through conduit  52   a ,  52   c ,  52   e ,  42   c ,  12   k , and  12   l  into cavity  18  of new container  20  and out through segments  12   a  and  100   a  into container  90 . The clean air may be drawn towards vacuum source  92 . 
     System  10  then instructs vacuum source  92  to draw a sufficient volume of saline fluid from container  56  through segments  52   b ,  52   c ,  52   e ,  42   c ,  12   k , and  12   l  into cavity  18  of new container  20  so as to clean fluidpath  15 . Clean air is then similarly drawn through conduit  52   a ,  52   c ,  52   e ,  42   c ,  12   k , and  12   l  into cavity  18  of new container  20 . System  10  then opens each of valves  30   a - i  to place cavity  18  with the wash solution in container  20  in fluid communication with fluidpath  15 . Pump  120  then initiates a single circulation the wash fluid through fluidpath  15  so that the entrapped fluid  22  in fluidpath  15  is displaced into new container  20  without beginning back into conduit segment  12   a . System  10  then closes valves  30   i ,  30   a  and  102  and operates vacuum source  92  to draw the fluid entrained within segments  12   l  and  12   a  and new container  20  into container  90 . 
     At this point, segments  12   b - k  contain saline solution. First pump  120  draws clean air from source  54  through segments  52   a ,  52   c ,  52   d ,  12   c - i , and  112  and out vent  114  until the previously wet segments are dry. Then, valve  30   g  is closed and pump  120  and vacuum source  92  cooperate to draw clean air from source  54  through segments  52   a ,  52   c ,  52   d ,  12   c - l ,  12   a  and into container  90 . With only segment  12   b  still containing saline solution, system  10  directs pump  120  to draw clean air through segments  52   a ,  52   c ,  52   e ,  42   e ,  12   k - l , cavity  18 , and segments  12   a - i , into segment  112  so that the remaining saline is collected in container  110  and the excess air is vented out vent conduit  114 . 
     Each of the product-carrying conduits of system  10  are now clean and ready to begin circulating a second fluid  22  from one of sources  44   a - c . Container  90  contains a small amount of hazardous product fluid  22  therein and may be handled appropriately with minimum exposure for the operator. Container  110  contains a used wash saline wash fluid. The operator may desire to replace new container  20  with a third and clean container  20  prior to introducing a new fluid of interest into system  10 . 
     The present invention thus provides a system and method for non-destructive sampling of a fluid within a fluid handling system saving both valuable fluid and the need to positively control and dispose of radioactive or biologically sensitive fluids. The present invention reduces the loss of fluid product resulting in higher efficiency and higher accuracy in predicting the characteristics of the fluid. The present invention provides a remotely automated system which reduces or eliminates operator exposure to the fluid as well as reducing or eliminating exposure of the fluid to the open environment. When handling a radioactive fluid such as Thalium-201 (which typically includes some level of Thalium 202), both an operator&#39;s whole body dose and extremity exposure is greatly reduced over the manual methods of the prior art. As the operator need not manually adjust the fluid characteristics, such as the pH level, the present invention greatly reduces variability resulting from operator error or from different operators performing the same task differently, this variability has been measured to three decimal places. The present invention also provides a system which is able to remotely and automatically clean the fluid handling surfaces in a matter of several minutes, replacing the longer more arduous cleaning required of the prior art. 
     While the particular embodiment of the present invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the teachings of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.