WO2003067021A2

WO2003067021A2 - Multi-parameter monitoring tool assembly

Info

Publication number: WO2003067021A2
Application number: PCT/US2003/003649
Authority: WO
Inventors: Kent D. Henry; Mark A. Watson; Zachary A. Gray; Stanley B. Smith; Shanen Onken-Shaw; Christopher J. Mc Kee; Craig A. Mc Kee; Ronny D. Harris; Neal W. Syverson; Todd Hochwitz
Original assignee: In-Situ, Inc.
Priority date: 2002-02-06
Filing date: 2003-02-06
Publication date: 2003-08-14
Also published as: AU2003210893A8; AU2003210893A1; WO2003067021A3

Abstract

A multi-parameter tool assembly (10) provides for monitoring of one or more parameters, such as those relating to water quality. As part of the tool assembly, a sensor head (30) is configured to receive and electrically interconnected with a plurality of interchangeable sensor head components (32, 33, 36). The sensor head components are specially configured to provide for the removal and insertion of sensors through the application of linear force. The housing (12) for the tool assembly, which may include a plurality of layers, is further configured for simplified assembly with the sensor head and other components through the use of at least one radially compressive sealing device (68, 70). The assembly is further connectable to a communications network wherein signals may be exchanged with one or more remote locations.

Description

MULTI-PARAMETER MONITORING TOOL ASSEMBLY

FIELD OF THE INVENTION The method and apparatus described herein relate to the configuration and operation of a sensor head component employable in a monitoring tool assembly, and more particularly to sensor head component configured as an accessory configured to perform functions on other sensor head components.

BACKGROUND OF THE INVENTION An ever increasing emphasis is being placed on systematic monitoring of environmental conditions in relation to ground and surface water resources. Examples of some situations where monitoring of conditions of a water resource may be desired include environmental monitoring of aquifers at an industrial site to detect possible contamination of the aquifer, monitoring the flow of storm water runoff and storm runoff drainage patterns to determine the affects on surface water resources, monitoring the flow or other conditions of water in a watershed from which a municipal water supply is obtained, monitoring lake, stream or reservoir levels, and monitoring ocean tidal movements.

These applications often involve taking data over an extended time and often over large geographic areas. For many applications, data is collected inside of wells or other holes in the ground. A common technique is to drill, or otherwise excavate, a number of monitoring wells and insert down-hole monitoring tools into the wells to monitor some condition of the water in the wells. One desirable feature of such a tool assembly is the capability to monitor one or more conditions at the site where the tool assembly has been located. In addition to such parameters as water level, temperature, and turbidity, it is also desirable to measure other parameters such water quality (i.e., the amount of contaminants in the water) which can be measured through the use of a conductivity sensor or other ion selective electrodes (ISE) sensors specially configured to detect the presence of one or more specific contaminants. A significant issue with regards to the employment of tool assemblies for monitoring water quality conditions is the relatively high cost of each unit. One reason for the high cost is that they use expensive components and designs that frequently require a significant amount of expensive machining and assembly. The tools assemblies often require the complex assembly of many components and significant manufacturing expenses are often required to provide structures for coupling the components and for electrically interconnecting the components. Furthermore, assembly and disassembly of components of the down-hole tools frequently require the use of wrenches or other tools, and sometimes special tools. This complicates use of the down-hole monitoring tools, and providing features on the down-hole tools to accommodate tools required for assembly and disassembly often requires machining, which significantly adds to manufacturing costs. Furthermore, electrical interconnections between components typically require special keying of the components, or of the electrical connectors between the components which result in difficulty of use and a possibility for tool damage or malfunction due to misalignment.

In addition to the high cost of monitoring wells and down-hold monitoring tools, a significant amount of ongoing labor is typically required to maintain the tools and to obtain and use data collected by the tools. For example, it is frequently necessary to have someone visit the monitoring wells at periodic intervals to make sure that the tools are still working and to obtain data collected by the tools. Data must then be analyzed for use. The frequency between visits to a well may be a function of a number of variables, such as the reliability of the tools, the frequency with which batteries need to be replaced, and the capacity of the tools to collect and either store or provide access to the data. Moreover, many down-hole tools are difficult to service and must be returned to manufacturers and distributors for even relatively simple service tasks such as changing batteries in the tool. There is a significant need for tools that are simple to manufacture and assemble, require less attention, and are easier to service.

SUMMARY OF THE INVENTION The inventors have recognized that it would be advantageous to provide a multi- parameter monitoring tool which is easy to assemble and service, and is connectable to a communications network. The inventors have further recognized that the multi-parameter monitoring tool may be easily reconfigured to monitor selected parameters or perform various operations depending on the environment within which the monitoring processes will be performed.

Described herein is a multi-parameter monitoring tool assembly employable for monitoring in a number of environments, which include: groundwater, surface water and/or flow cells. The tool assembly may include an electronic housing portion which is substantially cylindrical in shape and within which a power supply and electronic components are positionable. The tool assembly further includes a sensor head which is connectable thereto and is configured to include a plurality of ports. Each port is configured to receive, engage and electrically interconnect which an interchangeable sensor head component wherein the interchangeable sensor head component is engaged and disengaged in a port through application of a linear force.

In particular, the plurality of ports are each substantially cylindrical in shape and are further configured to mechanically and electrically engage interchangeable sensor head components which are substantially cylindrical in shape and include at least one radially compressive sealing device disposed around the exterior of the cylindrical portion. Each sensor port may further comprise at least two different portions of different diameters, with a larger diameter occurring within the sensor head so as to provide for the expansion of the radially compressive sealing device into the increased volume. The radially compressive sealing device provides an environmental seal as well as a resistive force keeping the particular interchangeable sensor component in the port. To further provide for the plug-in connections established with the interchangeable sensors, atmospheric pathways may be configured into the sensor head so as to interconnect the ports. When one of the interchangeable sensor head components is inserted in a port, certain atmospheric pressure may build up beneath the component in the sensor port due to the environmental seal created by the radially compressive sealing device disposed around the exterior surface of the component. Through the atmospheric pathways, this atmospheric pressure is transferred to the other ports in the sensors head, and if there is an empty sensor port, exhausted into the atmosphere. In the situation where all the ports are filled, the last sensor plug to be inserted will create an increase in pressure whose effect will be reduced because it is spread out within the existing atmospheric pathways.

Further connectable to the sensor head may be a circuit board device which includes thereon a plurality of electrical interconnection plugs positionable within the ports configured in the sensor head opposite the sensor head components. These electrical interconnection plugs are configured to electrically interconnect with the sensor head components upon insertion of said sensor head component in a particular port. Disposed around the body of the connected portion, may be at least one radially compressive sealing device which upon insertion of the connector within the port of the sensor head, provides and environmental seal. Mounted on the circuit board device on a side opposite the plug in connectors may be a modular plug-in connection device. The modular plug-in connection device is in electrical connection with the electrical interconnection plugs and is further electrically connectable to a mating plug-in device so as to provide for the conduction of electrical signals to and from electronic components with the housing.

For engaging within a port in the sensor head, each of the interchangeable sensor head components may be configured to include a plug portion around which a least one radially compressive sealing devices may be positioned. The plug portion may further include a number of electrical connectors which are configured to electrically engage with the electrical interconnection plugs positionable in the sensor head. In one configuration of the sensor plug, two radially compressive sealing devices may be disposed around it's exterior, one specifically employed for expanding into the increase volume portion of the sensor port, and the other for providing additional environmental seal. The sensor plug may be further configured to establish a number of different types of electrical connections with the sensor head. These may include connections for passive sensors, active sensors, connection to accessories, as well as the establishment of electrical connections through the use of data ribbons.

The interchangeable sensors head components described herein may be configured as sensors for monitoring a number of different parameters or as accessories for performing more designated operations. Where the tool assembly is configured for monitoring water quality, the sensors may include active (powered) sensors employable for monitoring parameters such as pressure conductivity, dissolved oxygen, and/or turbidity, as well as, passive (unpowered) sensors for chemical detection and/or monitoring oxidation reduction potential (ORP). Sensors are also includable for monitoring temperature. Each of the sensors may be configured to monitor a single parameter and/or to monitor multiple parameters. Accessories may comprise stirring devices, wiper devices, and/or shutter devices.

Each of the sensor head components may be further configured with a memory device which is employed to store operational information for the particular interchangeable sensor head component. The operational information may include identification information. For sensor head components which comprise sensors, the operational information may further include calibration information. Once the sensor is installed in the sensor head this information may be retrieved from memory and employed in processing data signals generated by the particular interchangeable sensor head components.

Returning again to the housing portion of the tool assembly, this portion may include a plurality of housing layers. In one configuration, the housing may comprise inner and outer layers. The outer layer may be substantially cylindrical in shape and may be fabricated from a metallic material. The outer housing may be substantially without machined surfaces except for a groove located a predetermined distance from one end. To facilitate assembly, the sensor head may include a plurality of radially compressive sealing devices disposed around an outer portion. The portion of the sensor head including the radially compressive sealing devices may pass within the outer housing. Engagement occurs through compression of the radially compressive sealing devices against the inner surface of the outer housing. In order to resist rotation between the sensor head and the outer housing, the above-described groove partially engages one of the radially compressive sealing devices so as to generate a resistive force. The inner housing is also substantially cylindrical in shape and is sized to fit within the outer housing. The inner housing includes threaded portions at either end specifically configured to engage the threaded portions of other components of the tool assembly. The inner housing may be fabricated from a number of materials including plastics and metals. Included as part of the electronics assembly within the housing may be two or more circuit cards interconnected substantially without the use of wires and/or wire harnesses which require soldered connections. According to the invention described, interconnection between the two or more circuit cards may be established through simple modular plug-in connectors. As described above, an analog circuit board may be mounted on the sensor head on a surface opposite the sensor ports and within the housing when the tool assembly described herein is assembled. Disposed on one surface of the sensor head circuit board may be one portion of a plug-in connector pair with the necessary electrical connections running therefrom. Also included in the electronics assembly may be a main circuit board which also includes a mating set of plug-in connectors for electrically connecting with the sensor head circuit board. When assembled, the circuit boards are electrically connected through the plug-in connections, wherein the plug-in connection provides a portion of the support for the main circuit board. The inner diameter of the inner housing may also be sized to provide structural support for the main circuit board as it extends from the plug-in connector. Further included within the housing and connectable to the main circuit board may be a data ribbon which carries data and power signal to and from opposite ends of the housing.

The electronic assembly may further include one or more batteries which provide an internal power source for the tool assembly. The tool assembly includes a removable backshell which is specially configured to provide access to the batteries without interrupting data connections from the tool assembly to remote locations. The removable backshell may include first and second threaded portions, wherein the first threaded portion is employable for engaging a threaded portion of the inner housing and a second threaded portion configured to engage a quick-connect data connection device. The removable back shell may further configured to engage the outer housing in a manner similar to engagement between the outer housing and the sensor head described above.

Included as part of the removable backshell may be an electrode assembly specially configured to provide an electrical connections to the internal power source, which also includes an elastomeric connector configured to establish a compressive electrical connection with a circuit board included as part of the data quick connect. The elastomeric connector is positionable in an opening in the removable backshell proximate to the second threaded portion.

The data quick-connect is further configured to engage with the threaded portion of the battery removable backshell and to establish a data connection through the electrode assembly to the electronics within the housing. The data quick connect in conjunction with the battery removable backshell allows the data line to be removed and replaced without interrupting the internal power source and without the use of special tools. The data quick connect device may further be configured with a fluid path way which allows atmosphere pressure to be carried through fluid path way in the data line an interior volume of the housing.

The electronics portions of the tool assembly may comprise a Computing unit which includes a processor and memory having stored therein instructions readable and executable by the processor. The computing unit is in electrical connection with any sensor head components which are engaged and inter-connected in the sensor head. The computing unit is further configured to access the memory portion in each sensor head component and retrieve the operational information stored therein. Further, during operations of the tool assembly, the computing unit is configured to receive and process data signals generated by each of the individual sensor head components. As part of the tool assembly operation, the computing unit may be configured to store and implement a test schedule for each of the individual sensors connected in a sensor head. The computing unit may further run the test schedule for each sensor according to detected changes in magnitude of received data signals from each sensor. As part of the electrical system for the tool assembly, the computing unit is connectable to the ports in the sensor head over both powered and unpowered circuits. In order to substantially reduce stray currents in the system which may affect measurements being taken, high impedance buffers may be positionable in the unpowered circuits.

Positionable within the electronic housing is a barometric pressure sensor. As was described above, the electronics housing is configured with a fluid pathway through the data quick connect which provides atmospheric pressure within the electronic housing. In one configuration of the invention, the barometric pressure sensor may be mountable on the main circuit card. Barometric pressure readings provided by the sensor may be employed in the processing measurement signals generated by one or more sensors. The sensors may include a dissolved oxygen sensor and/or a water level sensor.

The monitoring tool assembly described above may be further included as part of a multi-parameter water quality monitoring system. Included in the system may be a central controller in connection with a communications network. The central controller includes functionality to exchange information over the communications network with configuration and monitoring information for each of the plurality of interchangeable sensors inserted in a sensor head for a particular tool assembly. The central controller may comprise a number of different devices such as a personal computer, a palm top computer, another tool assembly, as well as a top of well device. The communications network may comprise the Internet, the public switched telephone network, radio waves, as well as direct electrical connections. In situations where the tool assembly is located remotely from the central controller, a local modem/controller may be employed to facilitate communications between the central controller and the tool assembly.

Further described herein is a multi-parameter monitoring system which includes a plurality of multi-parameter monitoring tools connectable to a communications network, where each of the monitoring tools is configured to electrically interconnect with a plurality of interchangeable sensor head components. A central controller also connectable to the communications network, is configured to communicate with each of multi-parameter monitoring tools so as to extract operational information from the tool assembly which relates to the configuration of the sensor head components interconnected to the sensor head as well their operations.

The central controller is further configured to detect each of the multi-parameter tool assembly connected to the communications network, selectively access each of the tool assemblies and communicate so as to access, amend, and/or extract information stored in the tool assembly, relating to each of the interchangeable sensor head components interconnected with the access tool assembly. This selective accessing may be performed by placement of a unique address header in a message which is transmitted over in the communications network and identified by the addressed tool assembly. The operational information extracted from a particular tool assembly may comprise identification information for the components interconnected in that tool assembly. According to the system described herein, the sensor head components may comprise sensors and/or accessories. In the configuration of the invention where the tool assembly is configured to monitor water quality in location such as ground water, surface water and flow cells, the interchangeable sensors may be configured for monitoring a number of parameter which includes: conductivity, dissolved oxygen, pressure and/or turbidity, oxidation reduction potential (ORP), chloride, nitrate, chlorophyll, ammonium, and temperature. In the configuration of the multi-parameter monitoring tool assembly where the sensor head component is a sensor, the operational information may include calibration data. In the configuration of the multi -parameter monitoring tool assembly where the sensor head component comprises an accessory, this accessory may be a stirring, wiper, and/or shutter device.

The communications network over which central controller communicates with the multi-parameter monitoring tool assemblies may comprise at least one of: the Internet, the public switch telephone network (PSTN), a wireless telephone, as well as radio waves. The multi-parameter monitoring tool assemblies may be located at a remote site wherein communications with a central controller are facilitated through use of a modem/controller device. This modem/controller device may be configure to emulate at least one other system such that communications may be established with devices other than the central controller.

The central controller may comprise any number of different devices which include: a personal computer, a palm top computer, a well top device, as well as another tool assembly. The central controller may be further configured so as to visually present information related to each of the multi-parameter tool assemblies in communications with the central controller over the communication network. The visual information may be presented on a screen display device which also provides for manual entry of information related to the operations of the multi-parameter tool assembly. As part of the central controller operations, the central controller is configured to detect when at least one tool assembly is connected to the network, detect the sensor head components interconnected with the tool assembly and present a first screen display which provides detailed configuration information for the particular tool assembly including data for each of the individual sensor head components connected thereto. Further, the sentral controller may present a second screen display which provides for manual entry of parameter information for each of the sensors included in the sensor head components. A third screen display may be presented for manual entry of testing information for each of the sensors, as well as extracting and compiling test information gather by the tool assembly during the monitoring process.

Additional functions performed by the central controller may include the upgrading and/or replacing of firmware resident in a particular multi-parameter monitoring tool assembly.

With regards to the use of sensors interconnected with a multi-parameter monitoring tool assembly, various testing procedures may be employed. One procedure in particular includes the monitoring of dissolved oxygen in a volume of water. The procedure may include first positioning the dissolved oxygen sensor in the liquid to be monitored. As was disclosed above, liquid may comprise ground water, surface water, or water within a flow cell. In order to begin the test, an electrical pulse of a predetermined magnitude is initiated across the electrodes in the dissolved oxygen sensor. At a second period of time after the initiation of the pulse, a measurement of the current magnitude across the electrodes is taken. Once this measurement is taken, a coπection value related to the second period of time may be retrieved from memory and added to the measure value. This total comprises a final dissolved oxygen measurement which, depending on the configuration of the system, may be digitized and stored in memory for future access.

In order to conserve energy in the system, the first period of time may be equal the second period of time. That is, once a measurement is taken, the pulse may be terminated. Additionally, the above described measurement process may be performed on a periodic basis where each period is significantly longer than the first period of time.

The invention described herein may be further configured such that each of the multi-parameter monitoring tools in the system are configured to include at least one unactivated circuit connectable between a microprocessor device in the tool assembly and a sensor head component which is employable for monitoring at least one parameter. According to the system described herein, the unactivated circuit is further configured to include a high impedance buffer device so as to reduce cuπent magnitude through the un- powered circuit. This high impedance buffer device provides the benefit of reducing stray cuπents which may interfere with system operations.

In one configuration of the invention, the high impedance buffer device may include a micro powered operational amplifier. This operational amplifier may be connectable in a circuit with either an active or passive sensor. In the configuration where the operational amplifier is connectable to an active sensor, this circuit may further include a capacitive device connectable at the operational amplifier output which minimizes cuπent drive to un-powered circuitry, and a resistive element connected between ground and the output of the operational amplifier which provides dc bias. In the circuits where the operational amplifier is connected to a circuit with a passive sensor, a large magnitude resistive element may be connectable at the output of the operational amplifier. The resistive element minimizes cuπent drive to unpowered circuitry.

Further described herein is an apparatus and method for performing functions on one or more sensor head components interconnected in a sensor head for a monitoring tool assembly. The apparatus may comprise an interchangeable sensor head component specially configured as an accessory which includes an electrical connector portion for interconnecting with the sensor head. Extending from the electrical connector portion is a body portion configured to enclose a motor. The motor is further in connection with an accessory arm of a predetermined length and positionable at particular height so as to be movable by the motor in a target area.

In one configuration of the invention, the accessory is specially configured for cleaning and/or removing debris from other sensor head components interconnected in the sensor head of the monitoring tool assembly. As such, the accessory arm may be configured to hold a cleaning element, such as a cloth, brush, and/or abrasive material, at an end opposite the point where the accessory arm connects with the motor. Upon manual or automatic activation of the motor, the cleaning element may cyclically move within the target area in a manner whereby a particular surface of the interchangeable sensor head component is cleaned. For example, one or more interchangeable sensor head components interconnected in a sensor head may include windows or other surfaces which accumulate debris, such as algae or other waterbome particles, during the operation of the monitoring tool assembly. More specifically, sensors such as turbidity and pH may employ windows during their operation while sensors such as dissolved oxygen may use of membranes. The surfaces to be cleaned may be positioned in a target area for the accessory arm, such that upon activation of the motor the cleaning element contacts the particular surface and moves in a manner to remove the debris.

The cleaning element may be further configured to include one or more layers of elastic material. The elastic material provides that upon compression of the cleaning element between the accessory arm and the surface to be cleaned, an expansive force is exerted by the flexible materials so as to increase the force exerted upon the surface by the cleaning element for removing debris.

In another configuration of the invention, the motor is configured to rotate the accessory arm in a radius about the body portion. In this configuration, one or more sensor head components interconnected in the sensor head are positioned within the radius of the accessory arm and may be contacted by the cleaning element. In particular, the accessory described herein may be positioned in a central port in the sensor head for the monitoring tool assembly. One or more of the sensor head components may be interconnected in sensor ports around the central port, whereby a maximum number of sensor head components are contactable by the cleaning element during its operation.

In yet another configuration of the invention, the accessory arm may be configured to move a calibration a device such as a surface which reflects light at a known wavelength. With sensors that may be periodically calibrated, such as a turbidity sensor, the motor may be activated to move the calibration surface into a target area such as over a window behind which the sensor being calibrated is located. Once the calibration process is complete, the motor may then again be activated and the calibration surface moved out of the target area.

In the configuration of the invention where the motor is configured to rotate the accessory arm, the motor may be further configured to include one or more positional sensors which generate signals indicative of the rotational position of the drive shaft in the motor. This information is especially useful during the calibration process whereby that calibration surface may be positioned in a particular target area. Alternatively, positional information for the actuator arm may also be generated based on signals from one or more sensors incoφorated in sensor head components interconnected in the sensor head.

For example, the magnitude of the signals generated by a turbidity sensor is directly related to the amount of light detected through the window. As the accessory arm moves in front of the window of the turbidity sensor, this significantly affects the amount of light detected. The monitoring tool assembly may process this information in conjunction with other known information such as the radius of the accessory arm, the RPMs of the accessory arm, and the direction of movement of the arm, in order to generate positional information for the actuator arm. This information may then be further employed for positioning the accessory arm in a selected position.

The body portion may be further configured to include one or more electronic components such as a memory device upon which identification and other information relating to the sensor head component may be stored and accessed. With regards to the accessory component described herein, this information may include such things as model number and performance information for the particular accessory.

BRIEF DESCRIPTION OF THE DRAWINGS Figure la discloses a geometric view of the multi -parameter monitoring tool and Figure lb discloses an exploded view of same. Figures 2a-c discloses various views of the multi-parameter sensor head.

Figure 3a discloses a geometric view of an interchangeable sensor head component and Figure 3b discloses an exploded view of same.

Figures 4a and b disclose various views of a first embodiment of the conductivity sensor. Figures 5a-c discloses various views of a second embodiment of the conductivity sensor.

Figures. 6a-c discloses three configurations of an accessory. Figures. 7a-b discloses two configurations of an enclosure device. Figures. 8a discloses a breakaway view of the enclosure device including a second sensor head and Figure 8b discloses a breakaway view of the enclosure device including stirring mechanism.

Figure 9 discloses a breakaway side view of the multi-parameter monitoring tool. Figure 10 discloses a perspective view of the outer housing. Figure 1 la-b discloses views of the inner housing. Figure 12 shows an assembled view of the analog circuit card with sensor head. Figure 12b discloses an explode perspective view barometric and Figure 12c discloses a perspective view of the analog circuit card.

Figure 13 shows a side view of the main circuit board including barometric pressure sensor.

Figure 14a-c discloses views of the removable backshell including electrode.

Figure 15a-b discloses views of the data quick connect including printed circuit board.

Figure 16 discloses a system diagram for the electronics portion of the tool assembly.

Figure 17a-b discloses various configurations of the high impedance buffers employable in the tool assembly.

Figure 18 discloses a flow chart which describes the steps performed in performing monitoring operations for the dissolved oxygen sensor. Figure 19a-d is a system diagram which show the various configurations of the communications network employable to connect with the multi-parameter monitoring tool.

Figure 20 discloses multiple multi-parameter monitoring tools connected in a network configuration. Figure 21 discloses the system configuration for the central controller.

Figure 22 discloses a flow chart which describes the steps performed by the central controller in identifying tool assembly connected to the communications network.

Figure 23 discloses a flow chart which describes the steps performed by each of the tool assemblies connected to the communications network when transmitting . messages to the central controller.

Figure 24 discloses a flow chart which describes the steps performed by a tool assembly to collect data during the adaptive scheduling process.

Figure 25 discloses a flow chart which describes the steps performed in the upgrading or replacement of firmware in a tool assembly connected to the communications network.

Fig. 26a-c discloses various view of the sensor head component accessory.

Fig. 27 discloses a breakaway view of the body portion of the sensor head component accessory showing the positioning of the motor and electronics. Fig. 28 discloses a view of the sensor head for the monitoring tool assembly including the sensor head component accessory and a number of sensor head components interconnected therein.

Fig. 29 discloses an alternate configuration of the accessory arm.

DETAILED DESCRIPTION The present invention comprises a multi-parameter tool assembly employable for monitoring conditions in any number of locations, including ground and/or surface water, as well as within a flow cell. These locations may include insertion into a well or other hole. Specifically included in the multi-parameter tool assembly is a sensor head specially configured to receive and interconnect with one or more sensor head components. The sensor head components may comprise such things as a sensor or an accessory. The sensors may each be employable for monitoring a particular parameter. Further included in the multi-parameter tool assembly is an electronic system configured to direct at least one operation of the tool assembly and preferably substantially all operations. The electronic system may include a processor and memory having stored instructions readable and executable so as to direct operation. When one or more sensors are mounted in the sensor head, the computing unit is configured to identify and communicate with each of the sensors so as to take and process measurements. The multi-parameter tool assembly is also configured for interconnection with a data line so as to communicate with other systems, such as a central controller over data network.

Disclosed in Figures la and lb are assembled and exploded views, respectively, of the multi-parameter monitoring tool 10. The monitoring tool comprises a body portion 12 which is substantially cylindrical in shape, and enclosed within are the computing and power source components of the monitoring tool. Extending from the body portion 12 is an enclosure device 14, which in this view is a restrictor, which is also substantially cylindrical in shape. Formed in the restrictor are holes 15 which provide for the flow through of the liquid which is to be monitored. Although a restrictor 14 is shown in the embodiment of the invention shown in Fig. la, other enclosure devices, which will be described in greater detail below, are attachable to the tool assembly.

At the opposite end of the monitoring tool 10 is removable backshell 16, which as will be described in greater detail below, provides for easy access to batteries which are employed as a power source and are contained within the body portion 12. In connection with the battery removal backshell 16 is data quick-connect 18, which provides connections from one or more remote locations to the tool assembly, and is configured such that it is removable without the necessity of disconnecting the internal power source.

Disclosed in Fig. lb is an exploded view of the multi-parameter monitoring tool and shown in particular is sensor head 30, which is connectable with body 12 in a manner which will be describe in greater detailed below. Included on the sensor head portion is a male threaded portion 46, which is configured to engage female threads on enclosure device 14. Configured in the sensor block 30 are one or more ports 34. As will be discussed in greater detail below, the ports 34 are specially configured to receive and engage an interchangeable sensor head component 32. In one configuration of the invention, the interchangeable sensor head components 32 are substantially cylindrical in shape, however, both the ports 34 and the interchangeable sensor head components may be configured in other shapes depending on the particular parameter being monitored or function to be performed. As an example, pressure sensor 36 is substantially rectangular in shape but is still received by a specially configured sensor port in sensor head 30. Although the configuration as shown only includes five sensor ports for receiving interchangeable sensor head components, it is conceivable that this number may be increased or decreased depending on the particular environment within which the monitoring tool is operating and the available space in the tool.

As was mentioned above, the body portion 12 is configured to receive one or more replaceable batteries 38. In the prefeπed embodiment of the invention, the batteries are standard D-size cells, however, depending on the space available and the electronic configuration, other types of power cells may be employable. The replaceable batteries 38 are locatable within the housing 12 and accessible through removable backshell 16. Incoφorated into removable backshell 16 is a female threaded portion which is specially configured to engage a male threaded portion (not shown) of the housing 12. Also included in the removable backshell 16 is a female threaded portion configured to receive and engage with a male threaded portion configured on a data quick-connect 18. Certain electrical connections, to be disclosed below, are included in both the data quick-connect 18 and removable backshell 16 in order to provide for data connections. Disclosed in Figures 2a-c are detailed views of sensor head 30. As was discussed above, the sensor head 30 includes a number of sensor ports for receiving one or more interchangeable sensor head components. Specifically, the sensor head 30 may be configured to include a number different ports, such as port 34 which provide for engaging the interchangeable sensor head components, wherein other ports, such as ports 35 and 40 may provide for engaging and interconnecting with components other than those which are interchangeable. The sensor head 30 includes a number of features employable in the assembly of the monitoring tool. Specifically, included therein is a threaded portion 42 which is configured to rotateably engage the enclosure device 14. Also included are a number of grooves 44 which receive a radially compressible sealing device such as an O-ring, gasket, or similarly configured component. These sealing devices provide, at least partially, for the engagement of the sensor block 30 with the body portion 12. The threaded portion 46 of sensor block 30 also provides for the engagement of the sensor head 30 with the body portion 12. Shown in Fig. 2c is a cross-sectional view of the sensor head 30. Shown in particular is the configuration of the sensor ports 34 port which receives and engage the interchangeable sensors. Each sensor port 34 comprises a receiving hole 48 which is of a first constant diameter, where the receiving hole extends within the sensor head 30 to a predetermined depth. At the predetermined depth, the hole diameter expands to a second constant diameter 50 for a further depth in the sensor head. At the bottom of hole 48 is receptacle 52 which is specially configured to receive and engage a connector which is further configured to electrically connect with the interchangeable sensors when inserted in sensor port 34.

Sensor head 30 also includes an atmospheric pathway 53 which interconnects the bottom portion of each of the sensor ports. In the prefeπed configuration, each of the sensor ports 34 located around the outer perimeter of the sensor head 30 include an atmospheric pathway which provides an interconnection to the sensor port 34 in the center position of the sensor head. This atmospheric pathway between each sensor port reduces back pressure which may be created upon insertion of an interchangeable sensor head component in sensor head 30.

Disclosed in Figures 3 a and 3b are various views of the interchangeable sensor head component 32 which includes plug 60. As is shown in Fig. 3a, plug 60 is substantially cylindrical in shape and includes removal lip 62, which extends around the circumference of the plug, as well as grooves 64 and 66 within which a radially compressive sealing device may be positioned. The embodiment of the interchangeable sensor component shown in Fig 3a is a sensor 33, which is substantially cylindrical in shape and is sized to be positioned in plug 60. The sensor 33 may comprise any number of different types of water quality sensors which are employable in monitoring any number of parameters. These parameters may include conductivity, dissolved oxygen, oxidation reduction potential (ORP), as well as detection of trace elements such as nitrates, chlorides, and ammonium. Portions of the internal configuration and operation of these interchangeable sensors will be discussed in greater detail below. It should be noted that sensors such as those which are employed to measure pressure, turbidity, and temperature, may have a different configuration than a typical interchangeable sensor, and thus the sensor head 30 includes other ports to specially receive such a sensors.

Shown in Fig. 3b, is an exploded partial view of the sensor head component 32 including sensor plug 60. As is seen, the interchangeable sensor head component 32 includes a number of electrical leads 75 which are connectable to a number of electronic components including EEPROM 37. As will be discussed below, the EEPROM 37 is employable for storing and providing access to identification and other information about the sensor head component. The EEPROM 37 and electrical leads are positionable within plug 60. The electrical connector 74 may include a number of male electrical electrode 76 and a female electrodes 77 which provide for a plug-in engagement of the component with matching male and female electrodes within a port of the sensor head. Radially compressive sealing device 72 is positionable around a portion of the connector 74 and is insertable within cavity 76 so as to provide an environmental seal for the electrical connections.

As was mentioned above, the plug 60 includes grooves 64 and 66. These grooves are specially configured to receive radially compressive sealing devices such as the O- rings 68 and 70 shown in Fig. 3b. The puφose of the O-rings is to provide for a secure environmentally sealed engagement of the interchangeable sensor head device in the sensor head 30. According to the present invention, the use of threaded engagements for the interchangeable sensor head components has been avoided, as well as all of the necessary manufacturing and space considerations which go with threaded configurations. In order to engage and disengage an interchangeable sensor head components in one of the ports 34 in the sensor head 30, the plug portion of the interchangeable sensor is initially aligned with a selected port 34 such that the male and female electrodes of both the sensor plug and port are aligned. Once this is complete, the cylindrical portion of the sensor plug 60 is inserted in the selected port 34 such that both O-rings, 68 and 70, of the plug 60 pass into the hole of the first constant diameter 48. As the plug 60 is pushed further into port 34, the male and female electrodes, 76 and 77 of the plug 60 will engage with those extending into the sensor head and the bottom portion of the plug 60, will contact the bottom of the receptacle. Upon full insertion, the O-ring 70 positionable in the O-ring groove 66, will pass into the hole of the second diameter 50 and expand to fill the gap providing an environmental seal and creating a force for resisting ejection or removal forces on the sensor along its longitudinal axis. When fully plugged in, the second O-ring 68 will remain in the hole of the first constant diameter 48 and also act as an environmental seal.

Upon insertion of the sensor plug 60 in port 34, the atmosphere pathway 53 allows gases which would otherwise be trapped in the sensor port to pass out of other ports which do not cuπently have a sensor plug inserted therein. The atmospheric pathways incoφorated throughout the sensor head further provide that in the situation where the final interchangeable sensor is inserted when the other ports are filled, that the pressure built up caused by such insertion is shared by all of the interconnected sensor ports. The interchangeable sensor head components may be removed by applying an opposing linear force, using removal lip 62, of sufficient magnitude to compress the O-ring 70 into the first constant diameter hole 48, and applying the force until the interchangeable sensor is removed.

As was mentioned above, the sensor head components may comprise various devices such as interchangeable sensors or accessories. The interchangeable sensors typically are configured to monitor one or more parameters and the physical component for monitoring the parameter are enclosable within housing 33. The interchangeable sensors typically comprise one of two types. The first type of sensor employed in the monitoring tool is a passive sensor. Passive sensors do not require external power and typically only require an electrical circuit connectable across the sensing element. Different types of passive sensors include temperature sensors and chemical detection sensors employing ion selective electrodes (ISE). A second type of interchangeable sensor is an active sensor which requires external power source in order to perform its monitoring functions. Typically, an active sensor will include at least two additional electrical leads to conduct power to the sensor electronics. Examples of active sensors employable in the monitoring tool are pressure, conductivity, dissolved oxygen, and turbidity sensors. According to the invention described herein, each sensor (either passive or active) may be further configured to monitor multiple parameters. As such, each probe may be configured with multiple passive and/or active sensing elements. Electrical connections to the probe may be configured such that unique signals generated by the different sensing elements may be identified and read by the tool assembly electronics. As was mentioned above, one type of interchangeable sensor which is employable with the multi-parameter monitoring tool is a conductivity sensor. Shown in Figures 4a and b is one configuration of a conductivity sensor 80 which is employable for monitoring the amount of contaminants or other foreign substances which may be contained in the water. In the configuration shown, the conductivity sensor 80 includes two slanted surfaces 82 and 84 incoφorated into the cylindrical body. Electrodes employed in measuring conductively are positionable on the slanted surface. The use of the slanted surfaces provides the distinct advantage that as the multi-parameter monitoring tool assembly is placed in the liquid to be monitored, in typical vertical positioning, air bubbles will not form on one or more of the electrodes interfering with the taking of accurate readings.

Another configuration of a conductivity probe is disclosed in Figures 5a-c. The probe 90 in this configuration includes an internal channel 92 with at least two opposing surfaces 93 and 95. Positionable on each of the opposing surfaces are the electrodes employed by the system in monitoring the conductivity of the water. Shown in Fig. 5b is a cross-sectional view of the probe, which shows in particular opposing surface 93 with electrodes 96 and 98 positioned thereon. Positioned opposite electrodes 96 and 98 on surface 95 is another set of electrodes (not shown). Also passing through the body of probe 90 are vent holes 94. These vent holes are employable such that when the conductivity probe is submerged in water (and positioned vertically) any air bubbles which may have been trapped in channel 92 will pass out hole 94 and will not interfere with any conductivity measurements.

As was mentioned above, sensor head components may also be configured as various types of accessories. These accessories may include one or more mechanical or electro mechanical components configured for performing a particular task. Accessories, as with the sensors, are installable in plug 60. The body portion which extends upwards from the plug portion would include the necessary electro-mechanical components for performing a designated task.

Disclosed in Fig. 6a-c are some possible configurations for accessories. Although the applicant shows only three possible configurations, any number of electrical or electro-mechanical devices may be employable as an accessory. Disclosed in Fig 6a is an accessory which is employable with an interchangeable sensor that has an external window which may periodically require cleaning. One example is a turbidity sensor. The accessory 400 shown in Fig 6a includes a mechanical arm 404 which extends from the body 402. On the end of the mechanical arm is a wiper device 406. When installed in the sensor head, the mechanical arm 404 provides for extending the wiper portion over to the window on the interchangeable sensor and moving in a fashion so as to clear any obstructions, such as algae or other substances, disposed on the window of the sensor. Once the cleaning portion is finished the wiper portion moves away and is locked in position until it is again activated.

Disclosed in Fig. 6b is an accessory 410 configured as a stirring device. Contained with the body portion 412 may be an electrical motor and extending from the motor outside the body may be a drive shaft 414 upon which stiπing component 416 may be mounted. Upon activation, the electrical motor will spin the stirring component for a period time.

Disclosed in Fig. 6c is a shutter device which can be used either alone or in combination with the wiper device. Included in the shutter device is a mechanical arm 424 which extends from the body 422 of the sensor head component. Connected at the end of said arm is a shutter 426 which includes a portion which reflects light at a known wavelength. When the arm is activated, the shutter device can be positioned in front of the window of the sensor and since the visible portion reflects light at a known wave length it is employable to calibrate the sensing portion of the turbidity sensor. Once the calibration process is complete, the mechanical arm is employed to move the shutter away from the sensor and lock in place until a recalibration is requested. In one configuration of the accessory the wiper and shutter may be combinable in a single accessory.

Disclosed in Figs. 26a-c are further views of an embodiment of the 400 of Figs. 6a and b. As can be seen in figure 26a, accessory 300 includes a cylindrical body portion 302. This body portion that may be constructed from a water resistant plastic material which is the same or substantially similar to the material employed to construct the interchangeable sensors head components 32 described above. The body portion 302 is positionable in plug 304, which is the same or substantially similar to sensor plug 60 shown in figure 3. As can be seen in the bottom views shown in Fig. 26c, positioned within the plug are a number of male electrodes and female which provide for plug-in of the accessory with matching male and female electrodes within a port of the sensor head. Extending from the body portion 302 of the cleaning accessory is a drive shaft 306 which in turn is connected to an accessory arm 308. As will be discussed in detail below, the drive shaft 306 extends from a motor positioned within the body portion 302. The accessory arm 308 is connected to the drive shaft in a manner which provides for the rotation of the arm in a radius about the body portion. The accessory arm 308 may be constructed of any number of coπosion resistant materials with sufficient stiffness to connect with and cantilever outward from the drive shaft.

Connected to the accessory arm 308 is a functional device such as cleaning element 310. Although this view shows the use of a cleaning element, other components such as a calibration device, whose use will be described in greater detail below, may be employed with or instead of the cleaning element. According to the invention described herein, the cleaning element may comprise any number of items, such as cloth, a brush, and/or any abrasive surface which provide for cleaning away debris, such as algae or other waterborne debris, which may accumulate on a surface. Further incoφorated into the cleaning element may be one or more layers of a flexible material which generate an expansive of force against a surface being cleaned when the cleaning element is compressed between the accessory arm and the particular surface being cleaned.

Further incoφorated into the accessory arm 308 may be one or more attachment grooves 316 which are configured to receive and fixedly attach the cleaning element to the accessory arm 308. The grooves may be further configured such that upon periodic service of the multi-parameter tool assembly described herein, the cleaning material may be easily removed and replaced.

Disclosed in figure 27 is a breakaway view of accessory 300 which discloses in particular the internal electrical and electromechanical components. Shown in particular is electric motor 318 which is sized to fit within body portion 302. The inner diameter of the body portion is typically approximately .4 inches. In one configuration of the invention, the electric motor employed in the cleaning accessory is a series 0816S DC micromotor manufactured by Minimotor SA. Included as part of the motor assembly may be a selected reduction gear 320. In the configuration of the invention described herein, a series 08/1 reduction gear, also manufactured by Minimotor SA, may be employed. In one configuration of the invention, after reduction, the drive shaft typically rotates at about 15 RPM. One skilled in the art would realize that any number of electric motors are employable to move the accessory arm in a desired fashion, be it rotationally or otherwise, where such a device is sized to be positionable inside the body portion and is controllable through one or more electronic connections.

Also shown in Fig. 27 is the electronics portion 324 of the cleaning accessory. Electrical connections 325 and 326 comprise the power and return for powering the motor 318. The electronics portion 324 may be substantially similar to that which is included the interchangeable sensor head components described above. In particular, the electronics for the accessory may included an EEPROM device which is employable to store identification and other information about the particular accessory, where this information may include such things as model number for the accessory and identification and performance information for the motor.

In one configuration of the invention, the electric motor may be configured to include one or more positional sensors which provides feedback as to the rotational position of the drive shaft. Through further processing of this information, the location of the accessory arm may be determined and that information further employed in performing various functions. Positional information for the accessory arm may also be generated based on signals from one or more sensors interconnected in the sensor head. This method of determining position will be described in greater detail below.

The operation of the cleaning accessory in the multi-parameter tool assembly may be better understood through study of Figs. 28 a and b. As can be seen, a number of interchangeable sensor head components 32 may be interconnected in sensor head 30. The sensor head 30 is further connected to housing portion of 12. Also interconnected in the sensor head 30 is pressure/turbidity sensor 330, as well as the accessory 300. Each of the interconnected components, not including the accessory 300, may include one or more target areas (surfaces), such as surface 334 in sensor head component 32 and windows 332 in pressure/turbidity sensor 330, which the accessory 300 may be employed to clean. As part of the configuration of the system described herein, the accessory arm is of sufficient length such that as it is rotated by the drive shaft of the motor, the cleaning element wipes any surface which is at substantially the same height as the bottom of the accessory arm and is within the radius of the arm. As can be seen in the in the side view provided in figure 28b, one or more of the interchangeable sensors 32, as well as the pressure/turbidity sensor 330, are configured at a height substantially the same as the body portion of the accessory 300. Sensor head components not requiring cleaning may be configured at heights less than accessory 300. Shown in particular is the compression of the cleaning element 310 against the top of sensor head component 32 as the accessory arm 308 rotates.

Further shown in Fig. 28a is that by positioning the accessory in the most central port of the sensor head a plurality of components, including the pressure/turbidity sensor 330, are within the radius of the accessory arm, and may be cleaned by the cleaning element. It conceivable that the accessory 300 may interconnected in other ports within the sensor head, however this would limit the number of sensor head components within the radius of the accessory arm.

Any number of the interchangeable sensors may include one or more surfaces whose cleaning would benefit the operation of the sensor. For example, a dissolved oxygen sensor which includes a membrane through which oxygen and other gasses are diffused may be configured such that the membrane is at a height where it is cleaned by the cleaning element. Further, a pH sensor may include a pH sensitive glass which may periodically require cleaning. As with a dissolved oxygen sensor, the pH sensor may be configured at a predetermined height, and the glass positioned at the top of the sensor body such that when interconnected in the sensor head 30, the rotation of the accessory arm, including cleaning element, will wipe the glass.

As was described above, the accessory described herein may also be employable as a calibration device. Positionable on the accessory arm may be a shutter device which includes a surface which reflects light at a known wavelength. The shutter device may be used either alone or in combination with a cleaning element on the accessory arm. For example, disclosed in figure 29 is one configuration of the accessory arm 308 which includes both a cleaning element 340 and a shutter device 342.

With certain sensors such as the pressure/turbidity sensor, calibration processes may periodically need to be performed. As part of that operation, the shutter device is movable over one or more of the windows of the turbidity sensor and the reflected light into the sensor is compared against the stored value of the shutter to provide a calibration adjustment.

In order to properly position the shutter device over a particular surface, the system described herein may include the functionality to determine the rotational position of the accessory arm 308. As was described above, one way to determine this position is to configure the motor with one or more feedback sensors which monitor the rotation of the drive shaft and provide this information to a central controller. Another way to perform this operation is through analysis of output signals from one or sensors over which the accessory arm may pass. As part of the operation of the accessory, the accessory arm periodically moves over one more windows, behind which a turbidity or other light sensitive sensor may be located. As the accessory arm passes over a window it will block a portion of the light. This will significantly affect the output signal from the sensor. The central controller of the monitoring tool assembly may be configured to recognize this condition and using known values for the accessory, such as the rate of rotation and direction of rotation, may at any point in time calculate a rotational position for the accessory arm. Using this information, the accessory arm which includes a shutter device may be manipulated such that when a calibration procedure is to be performed, the shutter device is moved in front of a selected window. Upon completion of the calibration process, the arm may then be moved to a position which does not interfere with the operation of the sensor.

Referring again to Fig. lb, and Fig. 2a, it was noted that the sensor head 30 includes a threaded portion 42 for engaging a number of different tool assembly component. In Fig. lb, it was shown that the sensor head 30 may engage the restrictor device 14. The restrictor device 14 is ideal for exposing the water source to be monitored to the sensors, but still providing physical protection for these components. Two other components which are attachable to sensor head 30 are disclosed in Fig. 7a and b. Disclosed in Figs. 7a is a calibration cup 600 which is configured to threadably engage threads 42 of the sensor head so as to provide a environmental seal. The calibration cup is configured such that a calibrating solution 602 may be poured into the cup and then the cup attached to the sensor head such that each of the sensors may be exposed to the calibration solution. Once the calibration cup is attached to the tool assembly it may be reoriented in a different position so that one or more of the sensors 604 may be submerged and then exposed to atmosphere trapped within the calibration cup. Disclosed in Fig. 7b is a configuration of the tool assembly wherein a flow cell

610 is attached to the sensor head 30. The puφose of a flow cell 610 is to provide a means to expose the sensors in a tool assembly to a remotely located liquid source. Included as part of the flow cell is an inlet line 612 and an outlet line 614. The inlet and outlet are connected to one or more remote reservoirs or sources of the liquid to be monitored. The size of the input and output lines are known so that the rate of fluid passing through the flow cell is calculable

In yet another configuration of the invention, the tool assembly may be further configured to provide a greater amount of monitoring by employing a second sensor head. According to the configuration shown in Fig. 8a, a second sensor head 37 may be positioned within restrictor 14 or other enclosure device, opposite the first sensor head 30. As with sensor head 30, sensor head 37 includes a plurality of ports (not shown) which are substantially similar to those in sensor head 30 and are configured to receive and electrically engage one or more of the interchangeable sensor head components. A ribbon cable 39 may provide for the electrical interconnection between the sensor head and the electronics enclosed in housing 12.

Disclosed in Fig. 8b is yet another configuration of the tool assembly wherein a stirring device 630 is positionable proximate to the plurality to sensor head components positionable in the first sensor head. The stirring device 630 may be connectable to the restrictor or any other enclosure device described above. An electrical connection may or may not be established between the stiπing device 630 and the electronics contained within the tool assembly. The stirring device may comprise an electric motor with a drive shaft and propeller device which moves the liquid in a desired fashion. In another configuration of the invention, the stirring device may comprise a magnetic stiπer wherein a spinning magnet provides for the desired movement of the liquid.

Disclosed in Fig. 9 is a cutaway view of the multi-parameter monitoring tool 10, showing in particular the internal electrical components. Included therein are two circuit boards 100 and 104 which provide for the signal processing of the tool assembly. Circuit board 104 is mounted at the end of the sensor block 30 opposite the ports 34. The circuit board 104 is in electrical connection with a main circuit board 100 which in turn is connected via contact 108 to ribbon cable 112. This cable, in turn, extends to the far end of the assembly. Also shown are battery contact spring 144, as well as battery stop 113. The housing 12 may comprise any number of layers. In the configuration shown herein, an inner and outer housing are included. The outer housing 13, as shown in Fig. 10, may be manufactured of any number of different materials such as stainless steel or plastic. The outer housing 13 is configured as a cylinder without inner or outer engagement threads so that it would require a minimum amount of machining to manufacture. In order to engage with other components of the tool assembly, the inner diameter of the housing 13 is machined at a close tolerance. Also included a predetermined distance from the opening at one end of the outer housing is an internal groove 17 machined at a designated depth.

With regards to assembly of the outer housing with the sensor head 30, it was previously mentioned that the sensor block 30 includes grooves 44. The portion of sensor block 30 where the grooves are formed has an outer diameter, which is marginally less than the inner diameter of the housing 13. Positionable within the grooves 44 may be any number of radially compressible sealing devices. These devices may include O-rings, gaskets, or an X-seal. For description puφoses only, O-rings will be described as positionable in the grooves. During assembly of the tool, the bottom end of the sensor block 30, including O-rings, is placed within the outer housing 12 such that the O-rings are compressed against the interior surface of the housing 13. Upon full engagement, the outer housing will contact a stop portion of the sensor block 30. The compressed O-rings provide for an environmental seal as well as a mechanical force which resist disassembly of the components. In addition to, or as an alternate environmental seal, a flat compressive gasket may be positioned between the stop portion of the sensor head and the end of the outer housing 13.

Also employed in the assembly process between the outer-housing 13 and the sensor head 30 is the groove 17 machined into the interior surface of the outer housing 13. Refeπing again to Fig. 10, this groove is positioned at a pre-determine distance within the outer housing 13, such that upon assembly of the sensor head and outer housing, this groove partially engages one of the O-rings disposed around the sensor head. This partial engagement provides for a condition such that a desired resistive force is created which resist rotation of the outer housing relative to the sensor head 30. The additional resistive force provides for easier assembly and disassembly of components at the opposite end of the outer housing. The housing 13 also engages the battery removal backshell 16 in a substantially similar manner, although without the use of a machined groove. The configuration of the battery removal backshell 16 and its engagement with the outer housing will be described in greater detail below. The second portion of the housing 12 is inner housing 15 which is positionable within the outer housing 13. The inner housing may be comprised of a plastic material, although one skilled in the art would realize that this component may be constructed of many different rigid materials. Disclosed in Fig. 1 la and b are side and front views, respectively, of the inner housing 15. Both ends of the inner housing 15 include threaded portions for engaging other components. Specifically, female threads 120 configured on the interior surface of the inner housing 15 are employable for engaging the male threads 46 on sensor block 30. The male threads 122 disposed on the outer surface of the inner housing 15 are employable to engage female threads on the battery removable backshell 16. Also included in the inner housing is a battery stop 124, which extends across the inner diameter of the housing so as to block movement of the batteries relative to the electronics within the housing. The inner housing 15 is sized such that its outer diameter is only slightly smaller than the interior diameter of the outer housing 13. In order to connect the sensor head 30 to both the inner and outer housing, the inner housing will first rotatably engage the threaded portion of the sensor head. The outer housing may then be slid over the inner housing and then the outer portion of the sensor head, so as to compress and engage the seals dispose thereon.

One advantage of the two-piece housing 12 described above is that any number of different materials may be employed for both the inner and outer housings. Further, the inner and outer housings are configured such that they are both easily replaceable. For example, in the situation where a user wishes to switch outer housing materials (such as from stainless steel to plastic), all that is required is the removal of the battery removal backshell, sliding the outer housing over the engaging seals of the sensor head, removing the outer housing, sliding on a new outer housing, and then replacing the battery removal backshell.

As was mentioned above, the circuit board 104 and main circuit board 100 are connectable in a manner which, for the most part, avoids the use of external wires and wire harnesses which require the use of soldered electrical connections to circuit boards. Disclosed in Fig. 12a is a geometric view of the sensor head 30 with circuit board 104 attached thereto. Shown in particular are female connectors 106 mounted on the exposed side of the circuit board. Connectors 106 comprise a number plugs, each configured to receive a conductive pin of a matching electrical connector mounted in the sensor head.

Disclosed in Fig. 12b is a view of circuit card 104 showing in particular the connectors which pass within the sensor head 30. The electrical connectors 103 are wired via the circuit card 104 to female connector 106. Also mountable on the circuit card 104 is a temperature probe which extends therefrom. In the perspective view shown in Fig. 12b, it is seen that each of the connector plugs 103 includes a number of female and male electrodes configured to electrically connect with matching electrical connectors which are included in the sensor head components described above. Disposed around the exterior surface of each of the plugs 103 is a radially compressive sealing device 107 which provides an environmental seal in the sensor ports when these components are engaged. Also extending from the circuit board 104 is a temperature probe 109 which also is configured to pass within the sensor head 30. Included thereon is another compressible sealing device mounted proximate to a spring. Disclosed in Fig. 12c is a perspective exploded view of the sensor head 30 and circuit card 104 which shows in particular the manner in which the connectors pass within the sensor head 30. Shown on the sensor head 30 are ports 52 which are configured to receive the various connectors 103. When assembling the sensor head and circuit card 104, each of the connectors 103 is aligned with a particular port 52 and the connector passes within the port 52. The radially compressive sealing device 107 which encircle each of the connectors then provides an environmental seal. Fasteners may then be employed to fixably attach the circuit card 104 to the sensor head 30.

As was described above, the circuit board 104 is connectable to a main circuit card 100. Disclosed in Fig. 13 is a side view of main circuit card 100. Included on the circuit card 100 are male connectors 102 each configured to electrically engage with the female connectors on circuit board 106. In order to establish an electrical connection between circuit board 104 and main circuit board 100, the pins extending from electrical connectors 102 are aligned with the appropriate plugs in connectors 106. Once the plug- in connection is established, the main circuit board will cantilever peφendicular from the circuit board 104 as well as sensor head 30 in a manner which is enclosable within housing 12. The inner diameter of the inner housing 15 is sized such that when the main circuit board 100 is extending from circuit board 104, the interior surface of housing of provides support to the circuit board. Also included on the main circuit card 100 is barometric pressure sensor 115. The mounting of this barometric pressure sensor within the housing 12 provides for taking atmospheric pressure readings within this enclosure and then electrically providing this reading to the electronics for the tool assembly. As will be described in greater detail below, the data quick connect device with associated data line includes a fluid path way which provides atmospheric pressure within the housing 12. Anyone skilled in the art would realize that the barometric pressure sensor 115 may be mounted anywhere within the enclosure so as to provide a local pressure reading.

Also attachable to main circuit card assembly 100 is electrical connector 114 and data ribbon 112. This combination of components provide for the receipt and transmission of electrical signals to the far end of the tool assembly. Further, a spring 144 may be connectable to the circuit card so as to provide a grounding contact for the batteries positionable within the tool assembly.

The tool assembly 10 described herein further includes features for providing an uninterruptible power connection to the electronics in a manner which allows for the removal and reattachment of the data quick connect cable 20. Disclosed in Fig. 14a is an exploded view of the removable backshell 16. Included in the backshell are female threads 126 which are configured to engage the male threads on the inner housing 15 when the tool assembly is assembled. Grooves 127 are configured to receive radially compressive sealing devices so as to engage the outer housing 13 upon assembly of the tool. As with the engagement between the sensor head and the outer housing, engagement occurs by sliding the outer housing over this portion of the backshell until the stop portion is contacted. Also included as part of the battery removable backshell is insert 120, which compressively fits within the cover and provides for the positioning of electrode assembly 122. Passage 123 through the insert 120 is configured to include a set of female threads 125 which are sized to engage with data quick-connect device 18. In connection with electrode assembly 122 is the data ribbon 112, which runs to the main circuit board along the length of the interior of the tool assembly.

Passage 123 is also sized to receive insulative layer 129, within which multiple connector unit 124 is configured. A front view of connector unit 124 is shown in Fig.

14b. The multiple connector unit 124 is comprised of an elastomeric material upon which conductive traces are disposed. The multiple connector unit is described in detail in U.S. Patent 6,305,944 which is hereby incoφorated, in its entirety, by reference. The opposite side of electrode assembly 122 is show in Fig. 14c. Included therein is electrode 128 for providing an electrical contact to the batteries. Power from the batteries is also delivered to the tool assembly electronics through connector ribbon 112.

The final mechanical portion of the multi-parameter monitoring tool assembly 10 is the quick-connect device 18 and associated data line 20. Disclosed in Fig. 15a is a geometric view of the quick-connect device. Included therein is a threaded portion 130 which is specially configured to engage the threaded portion 125 in the removable backshell. Extending therefrom is data line 20 which can be of any known construction and include enough conductive lines which provide for the transmission and receipt of necessary data (and power) signals. The data line 20 is further configured to include a fluid pathway which provides atmospheric pressure to the interior of the housing when the quick connect device is connected to the backshell. The quick-connect device is removable from the assembly through disengagement of the threaded portion 130 from the removable backshell. As can be seen from reviewing the structure of the removable backshell, the backshell itself would remain engaged thus continuing to apply the necessary pressure through electrode 128 so as to maintain a power connection for the monitoring tool assembly electronics over data ribbon 112.

In order to provide for the proper alignment of the different conductive lines within data line 20, the quick-connect device includes a printed circuit board 135 substantially as shown in Fig. 15b. This printed circuit board is specially configured for establishing individual electrical connections through conductors 136 with the multiple connector unit 124 through application of a compressive force generated through engagement of the threaded portions. The manner in which this connection is established is described in U.S. Patent 6,305,944 which, as was mentioned above, is incoφorated in its entirety by reference. With regards to the electrical system portion of the tool assembly, disclosed in

Fig. 16 is an electrical system diagram for the multi-parameter tool assembly which, as will be described in greater detail below, is connectable to any number of different types of communications networks. The electronic system may be broken down into two major components: the analog card 154 and the main card 150. Included on the main card 150 is a microprocessor 178, which provides for the internal routing of electrical signals and the execution of various programming included in the firmware stored in memory. In connection with the microprocessor 150 is a communications transceiver 152. The transceiver performs a conversion between communication formats for signals transmitted from the tool assembly over the communications network. The transceiver also provides for format conversion of signals received over the communications network.

Also in connection with the microprocessor 178 are the program flash memory 156 and the serial flash memory 158. Program flash memory 156 is employed to store the version of firmware which the tool assembly employs for its operation. Incoφorated in the firmware are a number of processes which the tool assembly employs in various aspects of its operation. The serial flash memory 156 is employed to download firmware upgrades as well as store data accumulated in tests performed by the tool assembly. Included in the main circuit board is signal conditioning/multiplexer 168. This components acts as the interface for receiving signals from one or more remote sources. These remote sources include the analog circuit board 154 as well as other sensor inputs 170, such as from a turbidity sensor. Another input may be signal reference 172.

Connecting the analog circuit board to the main circuit board is connector 166. As was described above, this connector 66 may comprise a male and female multi-pin connectors mounted on the circuit cards. Included within the analog board 154 may be multiplexer 164 employable for selectively activating each sensor head component as well as signal buffers 162. The signal buffers are connectable to each of the sensor ports via connectors 160.

One electrical connection establishable between the analog circuit board and each sensor head component interconnected with sensor head is a circuit which is activated, in that it is employed for monitoring a particular condition wherein a signal is naturally generated between electrodes in the circuit, and the magnitude of the signal is measured to identify one or more conditions. An issue which exist with regards to the employment of unactivated circuits in the tool assembly, is that because of the common circuitry employed for the different types of sensors, certain stray cuπent may be created in these unactivated circuit which affect the accuracy of one or more of the measurements. One solution to substantially eliminating these stray cuπents is the use of the high impedance buffers 162 which are positionable in each of the circuits.

Disclosed in Figs. 17a and b are two separate configurations of the buffer, one which is employable with ports which interconnect with both active and passive sensors and the other which employable with ports that only connect with passive sensors. Disclosed in Fig. 17a is an active sensor buffer 180 which includes an op amp 184. The op amp is always powered to provide an always active high impedance input. The op amp is further micro powered so as to maximize battery life. Capacitor 186 is included in the buffer to prevent cuπent drive into unpowered circuitry. The resistor 188 provides DC bias for downstream circuitry. The values of resistance and capacitance for these elements may be chosen such that there is minimal attenuation of the signal being measured.

Disclosed in Fig. 17b is the configuration for the passive sensor buffer 182. As with the active sensor buffer, an always powered OP amp 184 is employed, which provides the active high impedance input. The resistor 190 at the output of the op amp is of the large ohm variety and minimizes the cuπent drive into the unpowered circuitry. This high impedance input virtually eliminates leakage cuπent through the sensor, which may affect sensor performance. According to the various embodiments of the invention described herein, the connectors 160 may comprise anything from two wire connections to a multiple wire ribbon cable. As was discussed above, in a typical configuration, each of the typical sensor ports comprises electrodes to establish a six wire connection. Each connector employed with an interchangeable sensor also includes electrodes for establishing a six wire connection. In certain situations such as with a temperature, pressure, or turbidity sensor, more or less electrical connections are required. For example, a temperature sensor may be a simple two wire connection, and may be positionable on the sensor head 30 such that it does not employ any of the sensor ports for the interchangeable sensors. Returning again to Fig. lb, it is seen that temperature sensor 33 which extends from sensor head 30 is positionable proximate to the interchangeable sensors but without employing a sensor port.

The sensor connections 160 may further comprise four wire or a six wire connectors configured for receiving and connecting with the interchangeable sensor head components. Most of the interchangeable sensor head components are configured to operate either over a four wire or six wire connection. More specifically, active sensors typically require a six wire connection (1 pair powering the sensor, 1 pair for the sensing element, and 1 pair to the EEPROM). Passive sensors typically only require 4 wire connection (1 pair for the non-activated sensing circuit, and 1 pair to the EEPROM). Accessories would typically require a powered pair to the motor portion and a pair to the EEPROM. The use of the EEPROM in systems operation will be described in greater detail below.

In one configuration of the invention, all of the ports may be configured with at least a four wire connection, however in certain situations, certain ports may be wired with six wires. If that is the case, the system described herein is further configured with detection software that detects when an active interchangeable sensor is used in a passive configured port. This detection process will be described in greater detail below.

In yet another configuration, the electronic connections 160 may established through use of a multi-wire ribbon which is connectable from the sensor to the analog circuit board through the port. In this situation a specially configured port may be employed. For example, a pressure sensor may require at least a ten wire connection in order to operate. In such a situation, the sensor plug may be specially configured such that the pressure sensor is not removable and a more permanent set of connections is established. In operation, the program flash memory 156 has stored thereon programming for tests or operations which are to be performed by various components of the tool assembly. This includes individual tests for each parameter to be monitored. As a first step in the operation, a determination may be made as to what type of sensor head component is connected in each port. Once the cuπent configuration of a sensor head is established, the micro processor 178, using the programming provided in memory, initiates and performs the particular function, whether it be a test procedure for a sensor or performance of a function by an accessory. As will be described in greater detailed below, testing information may be periodically provided back to a central location. Amendments to the tests and changes in schedule may be periodically received from the central location and these changes are implemented by the micro processor per the received instructions.

The first function performed in particular with regards to the insertion of interchangeable sensors in a sensor head components head 30 is a determination as to whether the plug into which the interchangeable sensor has been inserted is compatible with the particular type of sensor. For example, sensor head components which require an active connection would not be employable in a passive wired plug. The electronics of the tool assembly includes programming which extracts data stored in the EEPROM for each interchangeable sensor head component upon insertion in a port. This data includes identification information for the particular component. For sensors in particular, calibration information can also be retrieved from EEPROM, which is then employable by the system in processing signal measurements. The advantage of including the calibration coefficient in the memory for the sensor is that the sensor does not then need to be field calibrated. More specifically, the particular sensor is employable with many different tool assemblies without the need to ever calibrate the sensor for the tool. Other information which may be stored in the EEPROM for the sensor head components includes manufacture date, calibration date, operational range, serial number, hardware revision, actual sensor serial number, actual sensor model number, and production technician ID code may be stored thereon. All of this information is extractable from the EEPROM and may be stored in flash memory for the tool assembly.

Continuing on with the sensor identification process, the tool assembly is preprogrammed to determine that certain sensors such as conductivity and dissolved oxygen require a an active drive connection and measurement, while other sensors such as ISE sensors only require a passive measurement connection. After a particular sensor is installed in a port, the processor for the tool assembly will determine whether a signal is being received over all the designated circuits for that type of sensor. If all signals are not detected, a determination is made that the particular sensor has been improperly installed and an error message is generated which may be included in a reply message to be transmitted back to the central location. Once the configuration is set, the tool assembly described herein may be programmed to perform tests and initiate functions in response to signals received from a remote location or according to a pre-program schedule. Depending on the type and frequency of measurements to be taken, test programs can be established which provide for any number of test schedule scenarios. These scenarios may include taking readings simultaneously and taking readings in a sequential fashion. The advantage of the latter method is that a sequential method of taking measurements provides for the maximum conservation of power. Even when using a sequential measurement schedule, the frequency of certain measurements may be increase or decrease depending on the desired number of measurements .

In performing a monitoring process, typical steps include making an instantaneous measurement of signal strength across a particular circuit, and then using the calibration coefficients extracted from the EEPROM of the sensor in order to generate an accurate reading. This information may then be stored in memory and employed at a future time. Other measurements may require additional steps be performed in order to take a measurement. One of those measurements is the detection of dissolved oxygen. Provided in Fig. 18 is a flow chart which describes in detail the steps performed by the system described herein when taking dissolved oxygen readings. To begin, once the system detects that a dissolved oxygen sensor has been inserted in the sensor head, according to the programming provided for performing test, a dissolved oxygen reading is made part of the test schedule. As part of the initial communication with the dissolved oxygen sensor where identification and calibration information are extracted from the sensor EEPROM, a coπection value may be included as part of this information. To begin the monitoring process for dissolved oxygen, initially a pulse is transmitted over the powered circuit for the sensor over a first predetermined period of time. After waiting a second predetermined period of time, a reading is taken across the activated circuit in the sensor. Once the reading is taken, the circuit is deactivated and the coπection value is retrieved from memory and then used to coπect the measured value so as to provide an accurate dissolved oxygen reading. This coπection value may be directly related to time periods employed in the test schedule, such as the time between when a pulse is initiated and when the measurement is taken, as well as the total time between the end of the last pulse and the initiation of a new pulse. As is well known, a typical dissolved oxygen sensors require that a certain amount of time pass between the initiation of the pulse and a measurement so that the volume in which the measurement is taken stabilizes. In order to save energy and time, the system described herein employs the coπection value to account for the manner in which the dissolved oxygen reading stabilizes over time.

Once the dissolved oxygen reading is taken, the coπected value that may then be digitized and stored in memory for future access. The system may be set up such that each subsequent reading overwrites the previous reading in memory. The system may be configured such that upon request of a dissolved oxygen value, the last stored value is provided.

As was discussed above, the communications transceiver 152 is employable with a multi-parameter sensor assembly described herein in order to communicate with one or more remotely located devices. As such, the tool assembly is employable in various communications networks. Disclosed in Figures 19a-d are system diagrams for various configurations of communications networks within which one or more of the tool assemblies may communicate with a remotely located central controller. According to the invention described herein, a central controller may comprise a computer workstation which has software installed thereon specially configured for communicating with the multi-parameter tool assemblies described herein. The workstation also includes a connection to a communications network as well as means for communicating over same. The central controller may also comprise various devices such as a palm top computer locatable near one or more the tool assemblies but able to communicate to a number of the tool assemblies over the communications network. The central controller may also comprise a specially configured well top device configured to communicate with the tool assemblies located at the particular well where the well top device is located, as well as other tool assemblies interconnected through the communications network. In yet another configuration of the invention, one or more of the tool assemblies may be configured to directly communicate with one or more other tool assemblies in the communications network. A system user may also alter operations of a particular accessory connected to a tool assembly. Through the same dialog boxes employed for viewing and amending parameters, the cuπent configuration of the attached accessories may be presented and a schedule for performing various functions. Through the dialog boxes presented on the screen display, the schedule changes may be implemented for a particular accessories and then this information transmitted over the communications network to the identified tool assembly. This information is then stored in memory within the particular tool assembly. In the simplest configuration shown in Fig. 19a, the use of a communications network may not be required. A direct connection is established between the communications transceiver in the monitoring tool with the central controller. The connection in this situation may simply be a data line with sufficient bandwidth in order to handle these types of communications. In situations where the line is employed to provide power to the tool, a power line running from a power source may be incoφorated therein.

Disclosed in Fig. 19b is a configuration of a communications network in which the public switch telephone network (PSTN) 204 is employed as the medium for communications. In order to employ the PSTN, the central controller 198 is equipped with, or is in connection with, a modem 202. The modem is employed to establish a telephonic connection from the central controller over the PSTN 204. At a remote location, the modem/controller 206 is employed to establish a connection with the PSTN 204. The modem/controller 206 is in communication with the tool assembly 10. Functionality is also included in the modem/controller 206 to establish telephonic connections over the PSTN 204. The communications line may comprise a hard telephone line, or the modem/controller may comprise a cellular telephone device, which is employable to establish a telephonic connection over the PSTN via a wireless connection. The modem/controller 206 may also comprise any number of devices such as a palm top computer such as a pocket PC or a palm pilot which includes a modem, a well top device or another tool assembly. Any of the controllers described above may be further configured to provide emulation of functionality for allowing one or more tool assemblies which employ a certain set of standards to communicate with a network which employs a different set of standards. Programming included in the controllers would allow the device to make the necessary conversions so that the different devices can communicate.

Disclosed in Fig. 19c is yet another configuration of the communications network wherein radio transceivers are employed to provide for the exchange of signals between the central controller 198 and any remotely located tool assemblies. In this configuration, a radio transceiver 213 is in electrical connection with central controller 198 and is configured such that data signals received from the central controller are converted to electromagnetic signals, which are transmitted via antenna 210. At the remotely located site, antenna 212 is in turn connected to radio transceiver/controller 214. A connection is then established from the transceiver/controller 214 to assembly 10.

Disclosed in Fig. 19d is yet another configuration for the communications network. In this configuration, a communications network such as the Internet or a local area network (LAN) 218 may be employed as the medium to establish a line of communication. In one configuration of the invention, the central controller 198 may establish a telephonic connection with an Internet service provider 216 through which connections may be established over the Internet to the modem/controller 220 either through ISP 216 or directly to modem/controller 220 if it is employed as a node on the communications network. The modem controller 220 would also provide for the transmission of data signals back to central controller 198 over the Internet 218. One skilled in the art would realize that although only four configurations for a communications network are disclosed herein, any number of different configurations may be employable for establishing a line of communication between a central controller and one or more tool assemblies connecting to the communications network. As was mentioned above, a central controller may communicate with a plurality of multi-parameter tool assemblies over any of the communications networks. Disclosed in Fig. 20 is a system diagram showing a plurality of tool assemblies connected in a networked fashion. In order to establish a connection between tool assemblies and a remotely located controller, a plurality of network junction boxes 232 may be employed. These network junction boxes are configured to carry data and power signals to and from the tool assemblies connected in the network. Modem controller 230 provides for establishing the communication with a remotely located controller over any of the communications networks described above.

As part of the monitoring system described herein, the central controller 198 is specially configured to perform various functions with regards to communicating with the one or more tool assemblies connected in a network configuration. In one configuration of the invention, the central controller 198 may be a personal computer, palm top computer well top device, tool assembly, or other computing device upon which a monitoring system has been installed Disclosed in Fig. 21 is a system diagram, which shows in particular the monitoring system configuration for the central controller 198. Included in the central controller 198 is processor 450, which provides for internal routing of signals and execution of various processing modules. In electrical connection with the processor is communications interface 452 which provides for the processing of signals, which are received and transmitted from the central controller. The interface includes the necessary protocols for communicating over the different communications networks described above.

Also in connection with processor 450 is random access memory (RAM) 454, within which a number of the processing modules are loaded for performing the various functions of the monitoring system. The various processing modules may be initiated either automatically or through the receipt of various user inputs received from user interface 467. In one configuration of the invention, the user interface 467 may comprise a computer monitor, keyboard and mouse, or a pocket PC touch screen. Returning again to the processing modules in RAM 454, included therein is communications module 456 which is employed to identify tool assemblies connected to the network as well the generation and transmission of messages and data over the communications network, a parameters modules 458 which is employed to display or change various parameter settings the tool assemblies and sensors employed when performing tests, tests module 460 which is employed to load automated tests schedules on to the tool assemblies, manually initiate test programs and to extract test data generated by the sensors from selected tool assemblies, and finally a display/output module 464 which is employed to display various screen displays through the user interface such that various user commands may be received and processed. Also included in the central controller 198 are a number of databases which are employed to store information either generated by components in the communications network or used in operations of the monitoring system. Specifically, database 466 is used to store screen displays which are presented on the user interface such that system users may view system data and/or initiate various system functions. In one configuration of the invention, the monitoring system described herein maybe configured such that it operates in a Windows type environment and includes a number of pull-down menus and directory tree type structure for organizing information. For example, the communications network information may be organized in a screen display such that each COM port for the computer may be presented with its own node in a tree type directory structure. Beneath each of the COM port nodes may be a listing of the tool assemblies which communicate with the monitoring system through that particular node. Further, below each tool assembly node in the directory tree structure may be additional nodes which include itemized information for the sensor head components interconnected to the sensor head including parameters to be monitored or functions to be performed. Associated with each node in the directory structure may be a screen display which presents information about the particular selection that has been made. With use of these display tools, the system user may move between screen displays to view information or initiate various functions which will be described in greater detail below. Also included in the central controller 198 is a tests results database 468. This database is employed to store and organize information which has been collected or extracted from the various tool assemblies.

As was described in great detail above, the tool assemblies described herein are configured to be positionable at locations remote from the central controller and to perform various tests and functions according to programming received from the central controller. As an example, the tool assemblies may comprise a surface monitoring multi- parameter monitoring tool assembly which is connectable to the communications network. The down well tool assemblies and/or surface monitoring tool assemblies include the functionality to take readings for the various parameters at designated times, store this data in a local memory and then provide this data when requested by the central controller.

In operation, the monitoring system employed for communicating with the various tool assemblies is initially installed on the central controller. Once operational, a first step to be performed is to identify the tool assemblies, including sensor head components installed in the sensor head, which are connected to the network. Disclosed in Fig. 22 is a flow chart which describes the steps performed by the communications processing module in identifying which tool assemblies are connected to the communications network. As an initial step a selection may be by a system user as to which communications node will be analyzed. Once this selection is made, a general identification message is generated and transmitted over the communications network such that each tool assembly connected to that particular node will receive the message. In one configuration of the invention, communication between components is established through use of a message based system. The message to be transmitted is comprised of data packets wherein the message includes a address header which identifies the message destination. The communications network employed herein is "open" in that each of the components connected to the network receives all of the transmissions, but only processes those message that are either addressed specifically or are addressed generally.

Returning again to the flow chart of Fig. 22, each tool assembly which receives the message, will generate a reply message, which the central controller in turn will wait to receive. As each reply message is received at the central controller, the information provided by the replying tool assembly is logged in memory and may be presented on a screen display in the tree type directory structure. The reply information includes identification information for each tool assembly as well as the figuration information for the sensors cuπently interconnected in the sensor head. This configuration information includes the identification and collaboration information stored in the EEPROM in each of the installed sensor head components. A listing for the probe, including cuπent sensor configuration, is also added to the directory for the com port being employed.

If multiple tool assemblies are connected to the communications network, it is possible that two or more tool assemblies may transmit a reply message at the same time, thus creating the situation where only one or none of the reply messages is received by the central controller. As such, the central controller has been configured such that each of the tool assemblies may have multiple opportunities to reply if a particular message is not received by the central controller. Returning again to Fig. 22, when the central controller receives reply messages, it continually updates a list of tool assemblies connected to the communications network which have responded to the message. After the receipt and processing of each reply message, a new general message is generated and transmitted requesting that all tool assemblies on the network identify themselves. Additional instructions are included in the new general message which directs the tool assemblies which have already responded, not to respond further.

Upon transmission of the new general message, the central controller will wait a selected time period in order to receive a reply. If no reply is received after the time period has elapsed, the central controller will retransmit the message. The central controller will again wait a period of time in order to receive a reply message. If no reply message is received after set number retries of the general message the process will end and the tool identification process will be complete.

The above-described information is displayable for all tool assemblies which provide a reply message. In the situations where connections are being established from more than one central controller, information gathered during one connect session may be saved in a file and employed by other central controllers.

Once all of the tool assemblies on a particular COM port are identified, the monitoring system may be employed to transmit messages to one or more of these components. As was described above, each of the each of the tool assemblies runs on a energy conservation mode, or "sleep" when not communicating with the central controller or performing tests. One feature which has been incoφorated into the system to further conserve energy is a selective activation process for selectively activating one or more tool assemblies when desired, without activating all the tool assemblies connected to a node. Messages which are generated by the central controller and transmitted to the individual tool assemblies are in the form of a data packets, which include an identifying byte in the header of the message. Included with the information stored about each of the tool assemblies stored in the central controller, is an multi-bit address header, which the central controller may employ when transmitting messages to particular tool assemblies. A general header may also be used in outgoing message to which all the tool assemblies will reply.

Disclosed in Fig. 23 is a flowchart which describes the steps performed by each of the tool assemblies which receive the messages. As was described above, each of the tool assemblies operates in a sleep mode wherein the tool assembly is turned off for the most part and is only operational to the extent that it monitors messages transmitted over the communications network. When the tool is in the "sleep" mode, it continually monitors the network for signals received and only activates when a message is detected which is addressed to the particular tool assembly or has a general message header.

Returning again to the flowchart in Fig. 23, during the sleep mode, a tool assembly will detect the receipt of an incoming message and perform the limited function of determining whether the message header includes the address for that particular tool assembly. Once the header is read, a query is made as to whether the message is a general message to which all tool assemblies connected to the communications network must respond. If this is so, the tool assembly is activated and the message is received and processed. If this is not a general wake-up message, the tool assembly makes a determination as to whether the message is addressed to that particular tool assembly. If the multi-bit message address matches the address for the particular tool assembly, it activates and begins processing the received message. If the multi-bit message address does not match the address for the particular tool assembly, the assembly stays in the sleep mode and continues monitoring incoming messages received over the communications network.

Also related to the selected activation of tool assemblies, is another feature incoφorated into the system which provides a level of certainty that when messages are generated and transmitted over the communications network, replies are indeed received from all the tool assemblies which have been addressed. As was described above, one draw back of having an open communications network such as that described herein, is that when the central controller sends out a general message in which all the tool assemblies are to reply, the possibility exists that all of the tool assemblies will reply at the same time thus interfering with each other. According to the invention described herein, the tool assemblies are configured to provide some certainty that all reply messages from the tool assemblies are received by the central controller.

Returning again to the flowchart disclosed in Fig. 23, once an incoming message is determined to be a general message or addressed to that tool assembly, the tool assembly will activate, receive and process the message. After the processing is performed, the tool assembly will generate a reply message to be sent back to the central controller. At this point, the tool assembly will first monitor the communications network to determine if any of the other tool assemblies are cuπently replying. This monitoring step is performed so that two or more tool assemblies will not reply at the same time. If a determination is made that another tool assembly is cuπently replying, the replying tool assembly waits a period of time then check the network again to determine if any other tool assemblies are replying. If no other reply messages are detected, the tool assembly will transmit its reply to the central controller. The tool assembly will continue to try to transmit a reply message until a clear network is detected. As was described above, the situation may occur where two tool assemblies do reply at precisely the same time to a general message and thus interfere with each other. As was described above, the central controller will periodically regenerate the message and transmit it so that the non-replying tool assemblies may respond. Once the messages are received, the steps disclosed in Fig. 23 are performed again by the tool assemblies. The monitoring system described herein is employable by a system user to perform a number of different functions with regards to the one or more tool assemblies connected to the communications network. As was disclosed in Fig. 22, the central controller 198 includes a number of processing sub-modules which may be selectively employed to perform various monitoring functions. In particular, the parameters sub- module 458 is used to view and amend any parameters for any sensor in a particular tool assembly. The parameters for each sensor are stored in the flash memory for the tool assembly, and are provided to the central controller during the initial tool assembly identification process. A various points-in-time, the system user may initiate an extraction of data from a particular tool assembly so that the test results may be compiled and viewed. As with the other functions, a message for the particular tool assembly is generated and transmitted to said tool assembly and the tool assembly responds by compiling information with regard to the specified test and transmits such information back to the central controller for further processing. When a system user wishes to view or amend a particular parameter of a sensor for a particular tool assembly, the listing of tool assemblies connected to a particular communications node may be displayed on the user interface and the tool assembly may be selected in order to view the sensors cuπent installed and operating in the sensor head. In one configuration of the invention, a screen display is provided which displays all the parameter information with regards to a particular tool assembly. Through dialog boxes presented in the screen display, various parameter information may be entered or amended. If a system user wishes to add change parameters for sensors of a particular tool assembly, a message is generated by the central controller which includes the parameter information as well as an address heading for that particular tool assembly. This generated message is then transmitted over the communications network and once received by the tool assembly, and implemented into its programming.

Yet another processing module employed in the monitoring system described herein is directed to programming and implementing tests in the tool assemblies. Using the directory tree structure described above, the system user may select to view information about tests programmed for one or sensors in a particular tool assembly. Tests to be performed are stored on the flash memory for the tool assembly and a listing of the tests is provided to the central controller during the initial tool assembly identification process described above. When this selection is made, a screen display may be presented which includes this program information. As was discussed previously, each of the tool assemblies include processing capability and memory. Stored into memory may be a number of automated tests which the tool assembly has been programmed to perform at designated intervals. When a system user selects to go into the testing mode for the system, the system user may retrieve and view information with regards to tests cuπently programmed into the device. This may be done for each sensor of each tool assembly. When viewing the information, the system user may have the option to manually initiate a program test or add a new test for one or more sensors. When adding a test, certain information and/or internal information may be entered, such as the particular sensor, and the type of test (linear, event, or linear average). Other options may be to program tests using adaptive scheduling. Steps performed in employing adaptive scheduling will be described in greater detail below.

Further, items which may be programmed for tests include measurement intervals for taking readings in an automated test as well as the point-in-time which a test is to begin. Once necessary information for the new test or the amended information is entered, the central controller may compile and transmit a message to the particular tool assembly instructing the assembly to load and execute the test.

As an additional feature of the system described herein, the system user may have the option of manually initiating or terminating a test for one or more sensors or a function of one or more of the accessories. The selection may be made through a dialog box in a screen display, and in turn, the central controller will generate a message for the particular tool assembly and transmit the same. According to the protocols described above, the central controller will then wait for a reply message either indicating that the test and/or function has begun or it has been stopped according to instructions. As was discussed above, one mode of performing tests is called adaptive scheduling. Through use of adaptive scheduling, space in the flash memory for the tool assembly may be conserved by only storing data points measured after the occuπence of significant events. A test may be programmed to be performed when a particular condition is detected in any sensor, a customized monitoring program may be initiated and the data which is collected during this time period is specially identified. One example of a time when such a program may be employed is when a water table is monitored for such conditions as flooding or flash floods. When a significant event occurs which causes the water table rises, this condition is detected it may be advantageous to provide a continuous monitoring of the situation while it exists and then to discontinue the monitoring once the situation has passed. This also applies to measuring dramatic rises in the detection of contaminants.

Disclosed in Fig. 24 is a flowchart which describes in detail the step performed by a tool assembly during adaptive scheduling and monitoring. Initially the tool assembly may be operating in a mode where measurements are taken at set intervals but are not stored in memory. During the monitoring, a particular condition may occur which exceeds a threshold value for the monitoring condition. If this threshold value is exceeded, the tool assembly will access memory and retrieve a test program designated for monitoring conditions during the particular detected condition. As part of initiating the test program, an identifier is added to the first page of data collected by the tool assembly indicating such things as the date/time/condition of the initial event detected. From that point, data points may be periodically taken and stored in the data pages. In order to conserve memory, it is not necessary to associate dates and times with data points that follow as long as the readings are taken after known periods. As the tool assembly and sensors continue monitoring, it may be detected that the measured condition has changed in a significant way which requires the use of another test program. For example, if the measured conductivity level exceeds a particular value, the frequency of readings taken may need to increase. When any type of change in test occurs, another identifier is added to the data page on which the new data points begins. As with the previous program, it may include date, time and condition which required the change. As was described above, additional readings may then be taken without the necessity of adding date or time information.

As the monitoring and the taking of data points continues, it may then be detected that the measured condition falls below the threshold of value and back to a "normal". At this point, the employment of the customized program may be discontinued and the sensors monitoring for that particular parameter returned to the idle mode wherein it only takes readings periodically and does not store them in memory. Adaptive scheduling may be performed for any number of different sensors in a tool assembly simultaneously. In the event that the test for the various sensors in a sensor head are performed sequentially, enough time would exist between the end of one sequence and the beginning of the next two performed any monitoring functions required by the adaptive scheduling procedure.

Yet another function performed by the test processing module of the central controller includes the extraction of test data for one or more sensors from the tool assemblies. When viewing particular tests for a tool assembly a selection may be made to extract data from the tool assembly for that particular test. Specifically, a system user may select the particular tool assembly in the directory tree structure and navigate to one or more existing tests for particular sensors. At this point, a selection may be made to extract test data for a particular sensor. In order to perform the above functions, the central controller will generate a message which is transmitted over the communications network and detected by the particular tool assembly. Once the message is received, the tool assembly will perform steps to extract the selected test data from the flash memory. This information is transmitted back to the central controller in a form of a message and through use of display/output module 464 disclosed in Fig. 21 and included in the central controller, the test information may be presented in the desired format. This may also be performed to retrieve a log of operations for an accessory.

One further feature of the system described herein is the functionality for a system user to update the firmware in a particular tool assembly as the firmware becomes available. Through the process described herein, it is done in a manner which ensures the integrity of the existing firmware as well as the new version which has been downloaded. To perform this process, a selection may be made to manually upgrade or replace the existing firmware. This selection may be made through use of an interactive screen display. If this selection is made, the central controller first identifies the appropriate firmware to be transfeπed and generates a message which includes the firmware. This message is then transmitted over the communication network to the particular tool. The steps performed by the tool assembly in downloading of the firmware is disclosed in Fig. 25. Initially, the message is received from the central controller indicating that the firmware is to be downloaded. The tool assembly may at that point indicate that a test is being performed and the download cannot occur until the testing is complete. This is purely as an extra precaution to protect integrity of the firmware on the tool assembly. One skilled in the art would realize that the system may be configured such that the test can be performed and firmware downloaded at the same time. Once it is determined that a test is not cuπently running, an entire copy of the upgrade firmware is downloaded directly into serial flash memory 150, as shown in the system diagram of Fig. 16. The cuπent version of the firmware is resident on the program flash memory 158. At any point after that the microprocessor may initiate a transfer of the upgrade firmware from the serial flash memory to the program flash memory. At this point the old firmware is overwritten. Once the transfer of the upgraded firmware is complete, a message is generated and transmitted back to the central controller indicating that the upgrade of the firmware was successful.

Various embodiments of the present invention have been described in detail. It should be understood that any feature of any embodiment can be combined in any combination with a feature of any other embodiment. Furthermore, adaptations and modifications to the described embodiments will be apparent to those skilled in the art. Such modifications and adaptations are expressly within the scope of the present invention, as set forth in the following claims.

Claims

1. A multi-parameter monitoring tool assembly, comprising: a first sensor head configured with a plurality of ports, where the plurality of ports is configured to engage and interconnect with an interchangeable sensor head component, whereby the plurality of ports is sized to receive one end of the interchangeable sensor head component, and engagement and disengagement of the interchangeable sensor head component within the plurality of ports occurs through application of a linear force upon the interchangeable sensor head component; and an electronics housing portion connectable to the first sensor head, wherein the electronics housing includes at least one electrical component configured to process signals generated by any of the interchangeable sensor head components engaged and interconnected with the first sensor head.

2. The tool assembly of claim 1 wherein the plurality of ports are each configured to receive and engage an insertable portion of the sensor component, wherein at least one radially compressive sealing device is disposed around the insertable portion.

3. The tool assembly of claim 2 wherein the plurality of ports includes first and second cylindrical portions, wherein the first cylindrical portion is configured to exit through an external surface of the first sensor head and include a first diameter, and the second portion is configured to begin a distance below the external surface and includes a second diameter larger than the first diameter, the plurality of ports being further configured such that upon insertion of the insertable portion through the first portion to the second portion, the radially compressive sealing device is configured to expand into the second portion creating a compressive force which resists withdrawal of the sensor component from the port.

4. The tool assembly of claim 1 wherein the interchangeable sensor head component may comprise at least one of: an interchangeable sensor and an accessory.

5. The tool assembly of claim 1 wherein the sensor head further includes a first circuit board device attached thereto, wherein the circuit board includes a plurality of electrical interconnection plugs mounted thereon for providing the interconnection with the interchangeable sensor head component.

6. The tool assembly of claim 1 wherein the first sensor head is further configured to attach to an enclosure device, wherein the enclosure device comprises at least one of: a restrictor, calibration container, and a flow cell.

7. The tool assembly of claim 6 wherein the enclosure device is further configured to include a second sensor head mounted proximate to the first sensor head, wherein the second sensor head includes at least one port for receiving at least one of the interchangeable sensor head components, and the enclosure device is further configured with electrical connection means to conduct electrical signals from the second sensor head to the first sensor head where the signals are further conductible to the electronic housing.

8. The tool assembly of claim 1 wherein the electronics housing comprises a plurality of housing layers.

9. The tool assembly of claim 8 wherein the outer and inner housings are further configured to engage a removable backshell so as to establish an environmental seal.

10. The tool assembly of claim 1 wherein the electronics housing is further configured to enclose at least one circuit card assembly, wherein the circuit card assembly is further configured to electrically interconnect with electronic components included on the first sensor head through use of a modular plug-in connector, a portion of which is incoφorated in the at least one circuit card assembly.

11. The tool assembly of claim 1 further comprising a computing unit including a processor and memory having stored therein instructions readable and executable by the processor, the computing unit being operably connectable with each of the interchangeable sensor head components.

12. The tool assembly of claim 1 which is further configured to be connectable to a communications network, wherein data signals may be exchanged between the tool assembly and at least one other device.

13. The tool assembly of claim 1 further configured for monitoring water quality in at least one of: ground water, surface water, and a flow cell.

14. An electronics housing assembly, comprising: an electronics housing configured to enclose at least one electronic component and at least one replaceable power source; a removable backshell connectable to the electronics housing which is removable to provide access to the replaceable power source, the removable backshell further configured to receive at least one electrode device which provides for conduction of power and data signals to the at least one electronic component; and a data quickconnect device connectable to the removable backshell and the at least one electrode device so as to provide data communications between a remote data source and the at least one electronic component, wherein the data quick connect is further configured to be removable from the removable backshell so as not to interrupt power between the portable power source and the at least one electronic component.

15. A connector assembly connectable to a housing of an electronic assembly comprising: a removable backshell connectable to a portion of an electronics housing, the removable backshell is configured to provide access to a replaceable power source within the housing, wherein the removable backshell is further configured to include an electrode device connectable to the replaceable power source, the electrode device further configured to conduct power and data signals to at least one electronic component locatable within the housing; and a data quickconnect device connectable to the removable backshell so at provide an electrical connection between a remote data source and the at least one electrode device so as to establish a data connection between the remote data source and the at least one electronic component, wherein the data quick connect is further configured to be removable from the removable backshell in a manner which does not interrupt power between the replaceable power source and the at least one electronic component.

16. A monitoring tool assembly comprising: a housing configured to enclose at least one electronic component within an interior volume, wherein the housing is further configured to be connectable to at least one fluid pathway so as to provide atmospheric pressure within the interior volume; and a barometric pressure sensor positionable within the housing which is configured for providing barometric pressure readings.

17. A multi-parameter water quality monitoring system comprising: a plurality of multi-parameter monitoring tools each configured to receive and electrically interconnect with a plurality of interchangeable sensor head components and to communicate over a communications network; and a central controller connectable to the communications network, said central controller is configured to communicate with each of the multi-parameter monitoring tools, wherein the central controller includes functionality to receive configuration information for each of the plurality of interchangeable sensor head components interconnected with each of the plurality of tool assemblies and to extract operational information therefrom.

18. The system of claim 17 wherein the central controller is further configured to detect each of the tool assemblies connected to the communications network, selectively access each of the one tool assemblies, and communicate with each of the tool assemblies so as to access, amend, and retrieve information stored in the accessed tool assembly, including data relating to each of the interchangeable sensor head components interconnected with the accessed tool assembly.

19. The system of claim 18 wherein the operational information includes identification for each of the interchangeable sensor head components interconnected with a particular one of the plurality of multi-parameter tool assemblies.

20. The system of claim 19 wherein the interchangeable sensor head components comprise at least one of: an interchangeable sensor and an accessory.

21. The apparatus of claim 20 wherein the central controller further comprises at least one user interface which is configured to display a plurality of screen displays which provide for the viewing and/or manual entry of information relating to the operations of the at least one tool assembly including the data for each of the interchangeable sensor head components connected thereto user commands.

22. The system of claim 21 wherein the central controller is configured to perform at least one of: detecting whether the at least one tool assembly is connected to the network; detecting which of the interchangeable sensor head components is interconnected with the at least one tool assembly; presenting a first screen display which provides detail configuration for the at least one tool assembly connected to the communications network including the data for each of the interchangeable sensor head components connected thereto; presenting a second screen display which provides for manual entry of parameter information for each of the interchangeable sensors interconnected with the at least one tool assembly, wherein the entered parameter information is provided to the at least one tool assembly over the communications network; and presenting a third screen display for manual entry of testing information for each of the interchangeable sensors interconnected with the at least one tool assembly, wherein the entered test information may be provided to the at least one tool assembly over the communications network; and extracting and compiling test information for each of the interconnected interchangeable sensors from the at least tool assembly. the tool assembly may employ for upgrade and/or replacement puφoses.

23. A method of measuring dissolved oxygen in a liquid, comprising the steps of:

(a) positioning the dissolved oxygen sensor in the liquid to be monitored;

(b) initiating a pulse of a predetermined magnitude for a first predetermined period of time across electrodes in the dissolved oxygen sensor;

(c) measuring a magnitude of the cuπent across the electrodes at a second predetermined period of time after the initiation of the pulse; and

(d) based on the second predetermined period of time, identifying a coπection value which is addable to the measured magnitude to identify a final dissolved oxygen measurement.

24. A multiparameter monitoring system comprising: a microprocessor device configurable for electrically communicating with a plurality of sensor devices, wherein each of the plurality of sensor devices is electrically connectable to the microprocessor over at least one unactivated circuit configured for monitoring at least one parameter; and at least one high impedance buffer device positionable in each of the at least one unactivated circuits which is configured to reduce cuπent magnitude through the at least one unpowered circuit.

25. A sensor head apparatus employable with a multi-parameter monitoring tool assembly, comprising: a sensor head body configured with a plurality of ports, where each of the plurality of ports is configured to engage and interconnect with an interchangeable sensor head component, whereby each of the plurality of ports is sized to receive one end of the interchangeable sensor head component, and engagement and disengagement of the interchangeable sensor head component within the plurality of ports occurs through application of a linear force upon the interchangeable sensor head component.

26. The apparatus of claim 25 wherein the plurality of ports are each configured to receive and engage an insertable portion of the interchangeable sensor head component, wherein a radially compressible sealing device is disposed around the insertable portion.

27. The apparatus of claim 25 wherein the interchangeable sensor head component comprises at least one of: an interchangeable sensor and an accessory.

28. The apparatus of claim 25 wherein the sensor head body is further configured to attach to an enclosure device, wherein the enclosure device comprises at least one of: a restrictor, calibration container, and a flow cell.

29. A sensor head apparatus employable with a multi-parameter monitoring tool assembly, comprising: a sensor head body including a plurality of ports for engaging and interconnecting with at least one interchangeable sensor head component, wherein the sensor head body further includes a circuit board device attached thereto, wherein the circuit board device includes a plurality of electrical interconnection plugs mounted thereon and positionable within the plurality of ports for providing the interconnection with the at least one interchangeable sensor head component.

30. The apparatus of claim 29 wherein the plurality of ports pass from one side of the sensor head body to an opposing side, and the circuit board device is configurable to attach to the opposing side of the sensor head in manner such that the interconnections plugs are positionable in the plurality ports and provide an environmental seal.

31. The apparatus of claim 29 wherein the engagement and disengagement of the interchangeable sensor within the plurality of ports occurs through application of a linear force upon the interchangeable sensor.

32. The apparatus of claim 29 wherein the first circuit board device further includes at least one modular plug-in connection device mounted thereon for electrically connecting with at least one other circuit card device.

33. An interchangeable sensor head component employable in a monitoring tool assembly, comprising: an electronic connector portion configured to establish an electrical connection to a monitoring tool assembly; at least one electronic component in connection with the electronic connector which is configured to perform at least one function; and a memory device accessible through the electronic connector which is configured to store and provide access to operational information for the interchangeable sensor head component.

34. The interchangeable sensor head component of claim 33 further configured as at least one of: an interchangeable sensor configured to monitor at least one parameter and an accessory.

35. The interchangeable sensor head component of claim 34 wherein the operational information includes at least one of: identification information for the interchangeable sensor head component.

36. The interchangeable sensor head component of claim 33 wherein the electrical connector portion further comprises a plug-in connector portion for providing electrical interconnection between the enclosed electrical apparatus and a mating plug-in connector positionable within a port.

37. The interchangeable sensor head component of claim 29 wherein the interchangeable sensor is further configured to monitor a plurality of the parameters.

38. An interchangeable sensor head component for use with a monitoring tool, comprising: an elongated housing portion configured to include an electrical component; and a base portion connectable to the elongated housing portion, where the base portion is configured to engage and disengage within a port through application of a linear force.

39. The interchangeable sensor head component of claim 38 wherein at least one radially compressive sealing device is disposed around the base portion, wherein the at least one radially compressive sealing device is positionable on the base portion so as to expand within a specially configured cavity upon insertion of the base portion in the port, and generate a force which resists removal of the base portion from the port.

40. The interchangeable sensor head component of claim 38 wherein the base portion further includes a plug-in connector portion for providing electrical interconnection between the included electrical component and a mating connector positionable within the port.

41. The interchangeable sensor head component of claim 38 wherein the electronic element is configurable as a sensing device for monitoring at least one parameter.

42. An interchangeable sensor head apparatus employable in a monitoring tool assembly, comprising: an electronic connector portion configured to establish an electrical connection to the monitoring tool assembly; a body portion extending from to the connector portion wherein the body portion is further configurable to enclose at least one motor; and an accessory arm connectable to the motor, where the accessory arm is of a predetermined length and positionable at a selected height so as to be moveable by the motor in a target area; and said accessory arm being further configured to fixably attach to a functional device on an end opposite the motor, wherein the functional device is movable by the motor in the target area.

43. The apparatus of claim 42 wherein the portion further encloses a memory device configured to store and provide access to operational information for the interchangeable sensor head component.

44. The apparatus of claim 42 wherein the functional device comprises at least one of: a cleaning device configured to remove debris from another device interconnected in the monitoring tool assembly in the target area and a calibration device positionable in the target area in order to perform calibration processes.

45. The apparatus of claim 42 wherein the motor is configured to rotate the accessory arm in a radius about the body portion.