Abstract:
One or more pieces of equipment (e.g., a locate wand, a marking tool) are used to perform an operation to identify, in response to a ticket, a presence or an absence of an underground facility at a dig area. Data relating to the use of the equipment to perform the operation is electronically processed to determine whether the operation was completed correctly. In one example, ticket information from the ticket also is processed with the data relating to the use of the equipment to determine whether the operation was completed correctly. In another example, the equipment includes a marking apparatus, and data relating to the use of the marking apparatus that is processed includes one or more of marker characteristic information, timing information, supply information and location information relating to one or more markers dispensed by the marking apparatus.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit under 35 U.S.C. §120 as a continuation of U.S. patent application Ser. No. 12/364,339, filed Feb. 2, 2009, and entitled “Methods for Evaluating Operation of Marking Apparatus.” 
         [0002]    Application Ser. No. 12/364,339 claims the benefit under 35 U.S.C. §120 as a continuation of U.S. patent application Ser. No. 12/363,951, filed Feb. 2, 2009, and entitled “Electronically Controlled Marking Apparatus and Methods.” 
         [0003]    Application Ser. No. 12/363,951 in turn claims the benefit under 35 U.S.C. §120 as a continuation-in-part of U.S. patent application Ser. No. 11/685,602, filed Mar. 13, 2007, and entitled “Marking System and Method with Location and/or Time Tracking ” 
         [0004]    Application Ser. No. 12/363,951 also claims the benefit under 35 U.S.C. §120 as a continuation-in-part of U.S. patent application Ser. No. 11/696,606, filed Apr. 4, 2007, and entitled “Marking System and Method.” 
         [0005]    Each of the above-identified applications is hereby incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0006]    This invention relates to marking systems and methods to mark the presence or absence of an underground facility in a dig area. 
       BACKGROUND 
       [0007]    Underground man-made objects, such as utility lines, cables and pipes (hereinafter “underground facilities”), are very susceptible to damage from excavation activities. Local and federal laws require that notification be given to owners of underground facilities in an area to be excavated before any excavation takes place. The owners of the underground facilities typically must locate and mark the location of any underground facilities. 
         [0008]    The tasks of locating and marking underground facilities can be performed by either the underground facility owner or by third party contractors. A marking tool is typically used to mark the ground, pavement or other surfaces in order to provide a visual indication of the location of underground facilities. Paint is commonly used as the marker, and it is typically applied using a paint marking tool. The color of the paint is typically chosen based on the type of facility being marked (e.g., red for a power line). However, other types of markers, such as other types of liquids, flags and stakes are also used, and different visual or other characteristics of the marker are used for representing different types of underground facilities. For example, the color, shape or other characteristic of a flag marker can represent a particular type of underground facility (e.g., a square shaped flag can be used to mark a power line). 
         [0009]    When paint is used as the marker, a worker marks the location of an underground facility using a paint marking tool to spray paint on the ground to mark the presence or absence of an underground facility. The paint marking tools typically used have a paint canister holder that is adapted to hold a single aerosol can of paint in an axial orientation with respect to the long axis of the aerosol can. The paint marking tool is typically designed to enable a user to walk or stand erect while dispensing the paint. 
         [0010]    When an underground facility is located, the worker will load a paint can of the appropriate color for the underground facility being marked into the paint marking tool. When it is time to mark a different type of underground facility, the worker must change the paint can to one of the appropriate color for the new underground facility being marked. 
         [0011]    Inaccurate marking of the underground facilities can result in physical damage to underground facilities, property damage, and/or personal injury during the excavation process that, in turn, can expose the underground facility owner or contractor to significant legal liability. When underground facilities are damaged and/or when property damage or personal injury results from hitting a underground facility during an excavation, the excavator may assert that the underground facility was not accurately marked by the entity that carried out the marking, while the entity that marked the underground facility will assert that the underground facility was properly marked. Proving whether the underground facility was properly marked can be difficult after the excavation, because in many cases the paint line used to mark the underground facility will have been disturbed or destroyed during the excavation process. 
       SUMMARY 
       [0012]    According to a first aspect of the invention, a method is provided for operating a marking apparatus that holds a marking dispenser for marking the presence or absence of an underground facility in a dig area, comprising: operating the marking apparatus in association with dispensing a marker from the marking dispenser onto the ground in the dig area to mark the presence or absence of the underground facility; logging one or more data elements associated with operation of the marking apparatus in an electronic record of marking apparatus operation; and analyzing at least part of the electronic record to provide an analysis result that is usable in evaluation of marking apparatus operation. 
         [0013]    According to a second aspect of the invention, a marking apparatus is provided to mark the presence or absence of an underground facility in a dig area, comprising: a housing configured to enable dispensing of a marker onto the ground for marking the presence or absence of an underground facility in a dig area; a marking dispenser holder affixed to the housing to hold a replaceable marking dispenser; an actuator to enable a user to cause dispensing of the marker from the marking dispenser onto the ground to mark the presence or absence of an underground facility in a dig area; and a processing device to log one or more data elements associated with operation of the marking apparatus in an electronic record of marking apparatus operation and to analyze at least a part of the electronic record to provide an analysis result that is usable in evaluation of the marking apparatus operation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments described herein and, together with the description, explain these embodiments. In the drawings: 
           [0015]      FIG. 1  is a block diagram of an exemplary marking system; 
           [0016]      FIG. 2  is a diagram of an exemplary marking tool; 
           [0017]      FIG. 3  is a diagram of an exemplary triggering system that may be used in the marking tool of  FIG. 2 ; 
           [0018]      FIG. 4  is a diagram of another exemplary marking tool; 
           [0019]      FIG. 5  is a flowchart of an exemplary process for marking an area; and 
           [0020]      FIGS. 6A-6C  are diagrams of exemplary entries that can be created. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following detailed description does not limit the invention. 
         [0022]      FIG. 1  is a block diagram of an exemplary marking system  100 . The system  100  may include a communication system  110 , an interface  120 , a local memory  130 , a processor  140 , a marker dispenser  150 , a triggering system  160 , a tag reader  170 , a location tracking system  180 , and a timing system  190 . In other implementations, system  100  may include additional or different components. In some embodiments, one or more of the communication system  110 , the tag reader  170 , the location tracking system  180  and the timing system  190  may be omitted, depending on the particular application of the marking system  100 . 
         [0023]    The system  100  may be used to dispense markers. In one exemplary application of the system  100 , the markers may be used to mark underground facilities, such as telecommunications (e.g., telephone and/or cable), power, gas, water, or sewer. The marker that is used to mark underground facilities may include a liquid, such as paint, or objects, such as flags, stakes, etc. 
         [0024]    A user may control the operation of the system  100  via interface  120 . In one implementation, interface  120  may include a touch screen interface that can provide various operational controls and status indicators of the system  100 , and can allow the user to navigate the controls by touching particular areas of the screen. In another implementation, the interface  120  may include another form of input and/or output, such as, for example, a display for displaying information and a keypad for entering information. In either situation, the interface  120  may provide operational controls to function as the triggering system  160 . 
         [0025]    The triggering system  160  may trigger the dispensing of markers and the storing of marking information. The marking information, which will be described in more detail below, may include information regarding a characteristic of the marker(s) being dispensed, time data (e.g., a timestamp and/or elapsed time information), and/or count data (e.g., a number of times that markers were dispensed). In operation, a user may engage a triggering mechanism in the triggering system  160  (explained in more detail below) in order to dispense the markers. When the triggering mechanism is engaged, the triggering system  160  may also initiate storing of the marking information. This may be done by sending a signal to the processor  140 , which may cause processor  140  to store the marking information in local memory  130 . Alternatively, or additionally, the processor  140  may store the marking information by transmitting the marking information for storage by a device or system external to system  100 . In one implementation, marking information may be stored only when a marker is being dispensed by the marker dispenser  150 . 
         [0026]    The marker dispenser  150  may hold the markers and may also contain an actuation mechanism (not shown in  FIG. 1 ) that causes the markers to be dispensed when the triggering system  160  is activated. As described above, the markers dispensed by the marker dispenser  150  may include a liquid (e.g., paint) or an object (e.g., flags or stakes). Details of the marker dispenser  150  will be discussed in more detail below. 
         [0027]    The system  100  may also include a tag reader  170 . In one implementation, tag reader  170  may include a device that can read tags. A “tag,” as the term is used herein, may refer to any item that is capable of storing machine-readable information, such as a barcode, a radio frequency identification (RFID) device, or a near field communication (NFC) device. A tag may be passive, active, or any combination thereof A passive tag may transmit data in response to signals received from tag reader  170 . An active tag may continuously transmit data. Tags can be attached to the markers that are loaded into the marker dispenser  150  and can incorporate data that corresponds to one or more characteristics of the marker (e.g., paint color if the marker is paint). Other examples of marker characteristics include, but are not limited to, the type of marker and a shape of marker. The tag reader  170  may incorporate an antenna (not shown) to enable reading the data from a tag (whether passive, active, or any combination thereof). The data read by the tag reader  170  can then be sent to the processor  140  for a determination of the corresponding characteristic. The corresponding characteristic can then be stored in local memory  130 , displayed by the interface  120 , and/or transmitted external to system  100 . 
         [0028]    Communication system  110  may include an interface for transmitting data to and/or receiving data from one or more external devices and/or systems located either local to or remote from the system  100 . Communication system  110  may include any type of interface, such as an interface for communicating via Ethernet, Bluetooth, Wifi, radio frequency (RF), a wide area network (WAN), or another type of network or protocol. 
         [0029]    In one implementation, communication system  110  may send marking information stored in local memory  130  to an external device/system and/or receive information from an external device/system. The marking information may be used by the external device/system to identify a marker dispensed by a user of system  100 , identify a time at which the marker was dispensed, and/or determine an amount of the marker used at a particular location. 
         [0030]    In one implementation, the system  100  may be used to accurately record the geographic location where markers are dispensed using data from the location tracking system  180  and/or the time at which the markers are dispensed using data from the timing system  190 . In one exemplary application of the system  100 , the location of markers used to mark underground facilities and/or the time at which the markers are dispensed can be accurately and reliably recorded. The marker that is used to mark underground facilities may include a liquid, such as paint. However, other types of markers, such as objects (e.g., flags, stakes, etc.), may be used in other implementations. 
         [0031]    The location tracking system  180  may include any device that can determine its geographic location to a certain degree of accuracy, such as a global positioning system (GPS) or a global navigation satellite system (GNSS) receiver. In another implementation, the location tracking system  180  can include a device that determines location using another technique, such as tower (e.g., cellular tower) triangularization. 
         [0032]    The location tracking system  180  may receive location-tracking signals (e.g., GPS signals) and determine its location based on these signals. In one implementation, the location tracking system  180  may be capable of determining its location within less than approximately thirty centimeters. 
         [0033]    The timing system  190  may include any device that can output time data to some level of accuracy (e.g., accuracy to the minute, the second, the millisecond, etc.). In one implementation, the timing system  190  may be capable of generating the time data itself. In this situation, the timing system  190  may take the form of a clock. In another implementation, the timing system  190  may receive the time data from another timing system. In this situation, the timing system  190  may take the form of a receiver. In some situations, it may be beneficial for the timing system  190  to be synchronized to another timing system. 
         [0034]    The triggering system  160  may trigger the logging of location and/or time data and the dispensing of markers. In one implementation, the system  100  may log location and/or time data only when a marker is being dispensed by the marker dispenser  150 . This may be accomplished via a triggering mechanism that, when actuated by the user, triggers both the marker dispenser  150  and the logging of location and/or time data. The location data may be received from the location tracking system  180 , and logged and stored in local memory  130  by the processor  140 . The time data may be received from the timing system  190 , and logged and stored in local memory  130  by the processor  140 . 
         [0035]    In operation, a user may engage a triggering mechanism in the triggering system  160  (explained in more detail below) in order to dispense the markers. When the triggering mechanism is engaged, the triggering system  160  may also initiate logging of location data received from the location tracking system  180  and/or time data received from the timing system  190 . This may be done by sending a signal to the processor  140 , which may cause processor  140  to store a log of the location and/or time data in local memory  130 . 
         [0036]    In one implementation, communication system  110  may send location and/or time data logs stored in local memory  130  to an external device/system and/or receive information from an external device/system. The location data logs may be used by the external device/system to accurately track the location where the markers were dispensed. The time data logs may be used by the external device/system to accurately track a time at which the markers were dispensed. 
         [0037]    As discussed above, marking information, count data, location information and/or time data may be stored, or logged, in local memory  130  by processor  140 . Alternatively or additionally, the marking information, count data, location information and/or time data may be transmitted to an external device or system, using communication system  110 , for storage and/or analysis. The logging and/or transmission of such information may be initiated by actuation of the triggering mechanism for dispensing of markers or by other events, such as operation of tag reader  170 . 
         [0038]    System  100 , as broadly described herein, may be particularly suited for incorporation into marking tools for marking underground utilities. As discussed above, a marking tool is used to mark the ground, pavement or other surfaces in order to provide a visual indication of the location of underground utilities. The type of marker that may be used includes paint that may be supplied in aerosol canisters that are oriented axially with respect to the long axis of the aerosol canisters. The marking tool enables a user to walk or stand erect while dispensing the markers. 
         [0039]    If system  100  is incorporated into a paint marking tool, a tag may be attached to the paint canisters to identify a characteristic of the paint, such as the color of the paint in the paint canister. The tag reader  170  can read this paint characteristic (e.g., the color information) from the tag when the paint canister is inserted into the marker dispenser  150 , and the processor  140  can display the color information read by the tag reader  170  on the interface  120 . Alternatively, or additionally, the color information may be provided to the user in other ways. For example, the color information may be audibly provided to the user (e.g., via a generated voice or a series of beeps or honks) The color information may also, or alternatively, be provided to the user visually in a manner other than via interface  120 . For example, the color information may be provided on an object worn or carried by the user (e.g., a pair of glasses, a bracelet, a ring, etc. having display capabilities and/or being capable of changing color). 
         [0040]    In one implementation, the processor  140  can estimate how much paint of a particular color has been dispensed. The processor  140  could do this by maintaining a separate timer for each color. The timer for a particular color would increase its count every time the triggering mechanism is activated and that color is mounted in the marker dispenser  150  (which can be determined by reading the tag on the paint canister using the tag reader  170 ). This information can be useful for managing paint inventory or determining whether the amount of paint used at a particular location is reasonable given the job to be performed at that location. 
         [0041]    A paint marking tool is just one possible application of system  100 . System  100  can be applied to any marking system that uses markers that can be affixed with tags. Any marker characteristic that a user would find useful can be stored on the tag that is affixed to the marker. 
         [0042]      FIG. 2  is a diagram of an exemplary marking tool  200 . For the description to follow, assume that the marking tool  200  uses paint as the marker. However, it should be appreciated that any other marker, such as another type of liquid, flags, stakes, etc., may be used in other implementations. 
         [0043]    The marking tool  200  may include a housing  220  with an elongated center housing portion  240 , a top housing portion  260  and a bottom housing portion  280 . The housing  220  may be formed of any at least semi-rigid material, and may be formed of a lightweight material such as aluminum or plastic. 
         [0044]    A paint canister holder  282  may be attached to the bottom housing portion  280 . The paint canister holder  282  may include an open-ended tubular structure that is attached to the bottom housing portion  280  by any suitable attachment mechanisms, such as rivets, adhesive, mechanical fasteners or the like. The paint canister holder  282  may be formed of any material such as injection-molded plastic, formed sheet metal or any other appropriate material that may be fabricated into an open tubular configuration or any other configuration that will serve to support a paint canister  284  with the paint canister axis substantially parallel to the housing  220 . 
         [0045]    A tag reader  246 , which may include a device that can read tags, may be mounted on or located within the housing  220 . The tag reader  246  may incorporate an antenna (not shown) to enable reading of data from a tag. When a tag  286  is attached to a paint canister  284  that incorporates data that corresponds to characteristics of the paint (e.g., paint color), the tag reader  246  may read that data. Other examples of marker characteristics include, but are not limited to, the type of marker and the shape of marker. The data read by the tag reader  246  can then be sent to a processor  268  for a determination of the corresponding characteristic. The corresponding characteristic can then be provided to the user, stored in local memory  270 , and/or transmitted external to marking tool  200 . 
         [0046]    The tag reader  246  may be mounted anywhere on the housing or on the paint canister holder  282 . However, the tag reader  246  does not have to be mounted anywhere on the marking tool  200  itself. For example, the tag reader  246  may be carried by a user. In general, the tag reader  246  may be mounted or located at any location, as long as it can receive data transmitted from the tag  286 . 
         [0047]    An actuation mechanism  288  may be attached to the bottom housing portion  280  at a location from which it can actuate the nozzle  290  of the paint canister  284 . The actuation mechanism  288  may include a rigid material that depresses the nozzle  290  when actuated. However, any mechanism may be used to actuate the nozzle  290  of the paint canister  284 . 
         [0048]    A handle  262  may be provided at the top housing portion  260 . The handle  262  may be formed of injection-molded plastic or any other appropriate material, and may be attached to the top housing portion  260  by rivets, adhesive, or any other suitable means. A mechanical trigger  264  may be provided on the top housing portion  260 . The mechanical trigger  264  may be located on the handle  262  and attached using any suitable means. 
         [0049]    The display  266  may be provided on the top housing portion  260 . The display  266  may include a touch-screen display for displaying information to a user, as well as acting as an input device. The processor  268  and the local memory  270  are located in the housing  220 . In one implementation, the processor  268  and local memory  270  may be located in the top housing portion  260  so as to be in close proximity to the display  266  and mechanical trigger  264 . In another implementation, the processor  268  and local memory  270  may be located elsewhere within the housing  220 . 
         [0050]    A timer  272  may be provided on the top housing portion  260  or may be located elsewhere within the housing. The timer  272  may include any device that can output time data to some level of accuracy (e.g., accuracy to the minute, the second, the millisecond, etc.). In one implementation, the timer  272  may be capable of generating the time data itself. In this situation, the timer  272  may take the form of a clock. In another implementation, the timer  272  may receive the time data from another device external to marking tool  200 . In this situation, the timer  272  may take the form of a receiver. In some situations, it may be beneficial for the timer  272  to be synchronized to another timer. The timer  272  may output time data to the processor  268 . 
         [0051]    A wireless communication antenna  242  may be located on the housing  220 , and used to transmit data, such as marking information, location information and/or time data stored in local memory  270 , to an external device/system and/or to receive information from an external device/system. 
         [0052]    A location tracking system receiver  292  for receiving location tracking signals (e.g., GPS signals) may be mounted inside the housing  220 . In the embodiment of  FIG. 2 , the location tracking system receiver  292  may be located at the bottom housing portion  280 . In another embodiment, the location tracking system receiver  292  may be located elsewhere within or on the housing  220  at a location that optimizes signal reception. However, the location tracking system receiver  292  does not have to be mounted anywhere on the marker tool itself For example, the location tracking system receiver  292  may be carried by a user. In general, the location tracking system receiver  292  may be mounted or located at any location, as long as it can receive the location tracking signals. 
         [0053]    The marking tool  200  may also include one or more input/output ports  244 , such as USB, SCSI, Firewire, Ethernet and/or other ports, for interfacing with other equipment and/or computers. 
         [0054]    In operation, a user operates the marking tool  200  while standing or walking in an upright manner. A user may control the operation of the tool  200  via display  266 , a mechanical trigger  264 , and/or a wireless or wired (hereinafter “wireless/wired”) interface that may be provided via wireless communication antenna  242  and/or input/output ports  244 . 
         [0055]    The various operational controls and status indicators of the tool  200  are displayed on display  266 , and the user can also navigate the controls by touching particular areas of the display  266 . Although a touch-screen display is one form of the display  266 , any other type of display or interface may be used such as, for example, a display for displaying information and a keypad for entering information. The user may use the display  266  to trigger the dispensing of paint and the storing, or logging, of marking information, location information and/or time data. 
         [0056]    The mechanical trigger  264  may trigger the dispensing of paint and the storing of marking information. In one implementation, the tool  200  may store the marking information only when paint is being dispensed. This may be accomplished by using a mechanical trigger  264  that, when activated by the user, triggers both the actuation mechanism  288  for the paint canister  284  and the storing of the marking information by the processor  268 . 
         [0057]    The mechanical trigger  264  may trigger the logging of the location data (e.g., GPS coordinate) and/or the time data, and the dispensing of paint. In one implementation, the tool  200  may log the location and/or time data only when paint is being dispensed. This may be accomplished by utilizing a mechanical trigger  264  that, when actuated by the user, substantially simultaneously triggers both the actuation mechanism  288  for the paint canister  284  and the logging of the location and/or time data by the processor  268 . The processor  268  may receive the location data from the location tracking system receiver  292 , the time data from the timer  272 , and store the location and/or time data in local memory  270 . 
         [0058]    The mechanical trigger  264  can trigger the actuation mechanism  288  via a mechanical connection between the trigger  264  and the actuation mechanism  288 . For example, the actuation mechanism  288  can be a rigid material that is connected to the mechanical trigger  264  via a mechanical linkage (not shown), in which case depressing the mechanical trigger  264  may cause the actuation mechanism to apply pressure to the nozzle  290  of the paint canister  284 . However, the mechanical trigger  264  may also, or alternatively, trigger the actuation mechanism  288  via an electronic connection. The electronic connection may be a hardwired connection or a wireless connection. If the connection between the mechanical trigger  264  and the actuation mechanism  288  is an electronic connection, the actuation mechanism  288  may include a mechanism for generating the force necessary to depress the nozzle  290  of the paint canister  284 . 
         [0059]    The wireless/wired interface may be capable of capturing signals that reflect a user&#39;s intent. For example, the wireless/wired interface may include a microphone that can capture a user&#39;s intent by capturing the user&#39;s audible commands. Alternatively, the wireless/wired interface may interact with a device that monitors a condition of the user, such as eye movement, brain activity, or heart rate. In either event, the wireless/wired interface may generate signals that may be sent to the processor  268  for processing. The processor  268  may use the signals to trigger the dispensing of paint and the storing of marking information, location information and/or time data. 
         [0060]      FIG. 3  is a diagram of one embodiment of a triggering system  300  that may be used in the marking tool  200  of  FIG. 2 . As shown in  FIG. 3 , the triggering system  300  may include the mechanical trigger  264 , a wireless/wired trigger  320 , and/or a touch screen display  266 , the actuation mechanism  288 , and a signal generator  310 . 
         [0061]    In operation, a user may trigger the storing of the marking information, the location information and/or the time data, and the dispensing of paint by activating the mechanical trigger  264 . The storing of the marking information, the location information and/or the time data and the dispensing of paint may also, or alternatively, be triggered by a trigger signal from wireless/wired trigger  320  or by choosing a command that is displayed on the touch screen display  266 . It should be appreciated that triggering system  300  may include a mechanical trigger  264 , a trigger signal from wireless/wired trigger  320 , a trigger command on a touch screen display  266 , or a combination of a mechanical trigger  264 , a trigger signal from wireless/wired trigger  320 , and/or a trigger command on a touch screen display  266  for initiating the storing of the marking information, the location information and/or the time data, and the dispensing of paint. 
         [0062]    When a user activates the mechanical trigger  264 , the actuation mechanism  288  and the signal generator  310  are both activated. The actuation mechanism  288  actuates the nozzle  290  of the paint canister  284 , thus dispensing paint out of the paint canister  284 . The signal generator  310 , when activated, sends a signal to the processor  268  indicating that the mechanical trigger is being activated. As discussed above, this signal could be used to trigger the storing of marking information and/or a timer for keeping track of how much paint of a particular color has been dispensed when a tag  286  that identifies the paint color is attached to the paint canister  284  that is mounted in the paint canister holder  282 . 
         [0063]    When a user actuates the mechanical trigger  264 , the actuation mechanism  288  and the signal generator  310  are both activated. The actuation mechanism  288  actuates the nozzle  290  of the paint canister  284 , thus dispensing paint out of the paint canister  284 . The signal generator  310 , when activated, sends a start log signal to the processor  268  for triggering the logging of location and/or time data. For example, the start log signal may instruct the processor  268  to read, or otherwise obtain, location data from location tracking system  180  ( FIG. 1 ) or the location tracking system receiver  292  ( FIG. 2 ), and store the location data in local memory  130  ( FIG. 1 ) or  270  ( FIG. 2 ). In addition, or alternatively, the start log signal may instruct the processor  268  to read, or otherwise obtain, time data from timing system  190  ( FIG. 1 ) or the timer  272  ( FIG. 2 ), and store the time data in local memory  130  ( FIG. 1 ) or  270  ( FIG. 2 ). 
         [0064]    The mechanical trigger  264  can activate the actuation mechanism  288  via a mechanical connection, e.g., a mechanical linkage, between the mechanical trigger  264  and the actuation mechanism  288 . Alternatively, the mechanical trigger  264  can activate the actuation mechanism  288  via a wired or wireless electronic connection between the mechanical trigger  264  and the actuation mechanism  288 . 
         [0065]    If a trigger signal from wireless/wired trigger  320  is used by the user to initiate marking information storing and paint dispersal, the wireless/wired trigger  320  may send a signal to both the actuation mechanism  288  and the processor  268 . The signal sent to the actuation mechanism  288  by the wireless/wired trigger  320  may result in the actuation of the nozzle  290  of the paint canister  284  by the actuation mechanism  288 . The signal sent to the processor  268  by the wireless/wired trigger  320  may trigger the storing of the marking information, the location information and/or the time data. The signals sent by the wireless/wired trigger  320  to the actuation mechanism  288  and the processor  268  may be sent via a wired or wireless connection. 
         [0066]    If a command on the touch screen display  266  is used by the user to initiate storing of marking information, the location information and/or the time data, and paint dispensing, the touch screen display  266  can send a signal to both the actuation mechanism  288  and the processor  268 . The signal sent to the actuation mechanism  288  by the touch screen display  266  may result in the actuation of the nozzle  290  of the paint canister  284  by the actuation mechanism  288 . The signal sent to the processor  268  by the touch screen display  266  may trigger the storing of the marking information, the location information and/or the time data. The signals sent by the touch screen display  266  to the actuation mechanism  288  and the processor  268  may be sent via a wired or wireless connection. 
         [0067]    The marking information may be used by an external device and/or system to identify which markers were dispensed, when the markers were dispensed, and/or an amount of markers that were dispensed. The marking information may be useful to determine whether a user dispensed the correct marker(s) (e.g., the correct color paint) in a particular location. Also, the marking information may be used to visually depict (e.g., in real time as the dispensing occurs) or reconstruct (e.g., at a later time after the dispensing is complete) the dispensing of the markers on an electronic representation of the area that is currently being marked or was previously marked. Also, the marking information may be used to determine whether the job was completed correctly (e.g., that the amount of paint dispensed at the location was reasonable given the job that was to be performed at the location). 
         [0068]    The logged location and/or time data may be used by an external device and/or system to track the dispensing of markers with a high degree of accuracy. The logged location and/or time data may be useful when disputes arise regarding whether the dispensed markers were placed in the correct location. Also, the logged data may be used to visually depict (e.g., in real time as the dispensing occurs) or reconstruct (e.g., at a later time after the dispensing is complete) the dispensing of the markers on an electronic representation of the area that is currently being marked or was previously marked. 
         [0069]    As shown in  FIG. 4 , the marking system  100  may be incorporated into already existing marking tools by locating the electronics on a board  410  that can be mounted onto an existing marking tool  400 . The processor  268 , local memory  270 , input/output ports  244 , tag reader  246  and/or wireless communication antenna  242  may be mounted on the board  410 . The board  410  can be attached to the marking tool  400  using any means, such as with fasteners, clamps, glue, etc. 
         [0070]      FIG. 5  is a flowchart of an exemplary process for marking an area. The process of  FIG. 5  may begin with a user of a marking tool, such as marking tool  200  ( FIG. 2 ), being dispatched to a location to be marked. The user might be given a ticket that identifies what utilities the user needs to mark at the location. The ticket might specify, for example, the location to be marked, the day and/or time that the location is to be marked, and/or whether the user is to mark the location for telecommunications (e.g., telephone and/or cable), power, gas, water, and/or sewer. The user might arrive at the location and take his/her marking tool out of his/her vehicle. In some situations, the user might load his/her pockets with extra markers (e.g., extra canisters of the same color of paint or different colors of paint). 
         [0071]    A marker may be loaded into the marking tool (block  510 ). For example, the user may load a paint canister  284  of the appropriate color into paint canister holder  282 . If the user is going to mark power, for example, the user might load a paint canister  284  containing red paint. The paint canister  284  may be loaded such that nozzle  290  extends out of the bottom of the marking tool  200 , as illustrated in  FIG. 2 . 
         [0072]    In one implementation, as described above, a tag  286  may be affixed to the paint canister  284 . The tag  286  may store information regarding one or more characteristics of the marker. For example, the tag  286  may identify the type of marker (e.g., paint, flag, stake, etc.), the color of marker (e.g., orange, red, yellow, blue, or green), and/or the shape of the marker (e.g., square, triangular, circular, etc.). 
         [0073]    The marker characteristic(s) may be identified (block  520 ). In one implementation, the marker characteristic(s) may be automatically determined. For example, data from the tag  286  may be read by tag reader  246  and sent to processor  268 . The processor  268  may determine the marker characteristic(s) from this data, and cause information regarding the marker characteristic(s) to be presented to the user (e.g., visually and/or audibly). 
         [0074]    For example, a user interface may identify a characteristic of the marker. The user interface may optionally request the user to confirm that the user intended to load a marker with the identified characteristic. The confirmation may establish that the user actually looked at the user interface before performing any marking operation. In one implementation, the user may be unable to activate a trigger for dispensing a marker if the user does not confirm that the correct marker is loaded. 
         [0075]    In another implementation, the marker characteristic(s) may be manually determined. For example, the user may specify the marker characteristic(s) via a user interface. The user interface may identify a number of possible characteristics (e.g., paint colors) of the marker. In this case, the user interface may request that that user select the paint color to be dispensed. The user interface may also identify the utility that corresponds to each of the possible paint colors so that the user can confirm that the correct marker is loaded. 
         [0076]    Trigger activation may be received (block  530 ). For example, the user may effect trigger activation by applying pressure to the mechanical trigger  264  with his/her hand. Alternatively, or additionally, the user may effect trigger activation by, for example, speaking a particular command to cause a trigger signal to be output by wireless/wired trigger  320 . Alternatively, or additionally, the user may effect trigger activation by touching a particular area of display  266  to cause a trigger command to be output by display  266 . 
         [0077]    It may optionally be determined whether to permit trigger activation (block  540 ). For example, the user may be required to confirm that a marker with the correct marker characteristic was loaded before trigger activation may be permitted. Alternatively, the marking tool  200  may be loaded with information from the user&#39;s ticket. In this case, trigger activation may be prevented when the marker characteristic of the marker does not match the ticket information. For example, if the ticket information indicates that the user is to dispense blue and yellow paint at a particular location, then activation of the trigger may be permitted if blue or yellow paint is loaded into the marking tool  200 , and activation of the trigger may be prevented otherwise. 
         [0078]    If activation of the trigger is permitted, then a marker may be dispensed (block  550 ), and marking information may be stored (block  560 ). To dispense a marker (block  550 ), the actuation mechanism  288  may be activated to cause the nozzle  290  of the paint canister  284  to be depressed, which may cause paint from the paint canister  284  to be output via the nozzle  290 . 
         [0079]    To store marking information (block  560 ), a signal may be sent to the processor  268 . The signal may be sent from the signal generator  310 , the wireless/wired trigger  320 , and/or the display  266 , as described above. The signal may instruct the processor  268  to store the marking information. For example, the processor  268  may store the marking information in local memory  270 . In this case, the processor  268  may create an entry in local memory  270 . Alternatively, or additionally, the processor  268  may store the marking information by transmitting the marking information for storage by a device or system external to marking tool  200 . 
         [0080]      FIG. 6A  is a diagram of an exemplary entry that may be created. As shown in  FIG. 6A , an entry may include a marker characteristic(s) field  610  and a timestamp field  620 . The marker characteristic(s) field  610  may include information regarding one or more marker characteristics, such as marker color, marker shape, or marker type. The information in the marker characteristic(s) field  610  is shown in  FIG. 6A  as “yellow” or “yellow paint”—although any type of descriptive information may be used. The timestamp field  620  may include time data that identifies the day and/or time that the marker was dispensed. The time data in the timestamp field  620  is shown in  FIG. 6A  as 10:45 a.m. on Oct. 20, 2005—although any type of date and/or time code may be used. As explained above, the marking information may be useful to determine whether the user dispensed the correct marker(s) (e.g., the correct color paint) in a particular location. For example, the user&#39;s ticket may identify what underground facilities were to be marked in the area. The marking information may help insure that the job was completed correctly. 
         [0081]      FIG. 6B  is a diagram of another exemplary entry that may be created. As shown in  FIG. 6B , an entry may include a marker characteristic(s) field  610 , a timestamp field  620 , and a count field  630 . The marker characteristic(s) field  610  and the timestamp field  620  may be similar to the similarly named fields in  FIG. 6A . The count field  630  may include information that identifies the number of times that the user activated the trigger to dispense a marker (e.g., yellow paint). The information in the count field  630  is shown in  FIG. 6B  as twenty-three--although any count value can be used. The information in the count field  630  may be useful to determine or estimate an amount of paint that was dispensed at the location and, thus, whether the amount of paint was reasonable given the job that was to be performed. 
         [0082]      FIG. 6C  is a diagram of another exemplary entry that may be created. As shown in  FIG. 6C , an entry may include a marker characteristic(s) field  640 , a timestamp field  620 , and an elapsed time field  650 . The marker characteristic(s) field  640  and the timestamp field  620  may be similar to the similarly named fields in  FIG. 6A . In this case, however, the marker characteristic(s) field  640  may additionally store an identifier that identifies a particular marker (e.g., a particular canister of paint). The identifier is shown in  FIG. 6C  as “12345”—although any type of identifier may be used. 
         [0083]    The elapsed time field  650  may include information that identifies the amount of time that has elapsed from when the user activated the trigger for dispensing a marker (e.g., yellow paint) to when the user ceased activating the trigger. The information in the elapsed time field  650  is shown in  FIG. 6C  as three minutes, forty five seconds, and three one hundredths of a second—although any time code can be used. The information in the elapsed time field  650  may be useful to determine or estimate when a supply of markers is nearly empty. The information in the elapsed time field  650  may help determine when to replace the canister. The elapsed time or a signal indicating that a supply of markers needs to be replaced may be presented to the user visually and/or audibly. The information in the elapsed time field  650  may also, or alternatively, be useful to determine or estimate an amount of markers used in a particular location. 
         [0084]    While three exemplary entries have been described with regard to  FIGS. 6A-6C , an entry may include more, fewer, different, or combinations of the fields shown in  FIGS. 6A-6C . 
         [0085]    The foregoing description is not intended to be exhaustive or to limit the description to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the invention. 
         [0086]    For example, the processors  140  and  268  can be general purpose computers. Alternatively, they can be special purpose computers, programmed microprocessors or microcontrollers and peripheral integrated circuit elements, ASICs or other integrated circuits, hardwired electronic or logic circuits such as discrete element circuits, programmable logic devices such as FPGA, PLD, PLA or PAL or the like. In general, any device capable of executing code can be used to implement processors  140  and  268 . Local memories  130  and  270  can be implemented with any type of electronic memory and/or storage device using any type of media, such as magnetic, optical or other media. 
         [0087]    Further, while a series of blocks have been illustrated in  FIG. 5 , the order of the blocks may differ in other implementations. Also, non-dependent blocks may be performed in parallel. 
         [0088]    Also, it has been described that information regarding an elapsed time can be used to determine or estimate when a supply of markers is nearly empty. In another implementation, a sensor may be used to detect a weight of a paint canister  284 . The sensor may be placed on the paint canister  284  or within the paint canister holder  282 . The weight of the paint canister  284  may be used to estimate how full or empty the paint canister  284  is. This information may be provided to an operator of the marking tool  200  visually and/or audibly. In one implementation, replacing the paint canister  284  may trigger the identification of the marker characteristic (e.g., paint color) by the tag reader  246 . This may help reduce the overall battery life of the tag reader  246  and/or the tag  286  by limiting the number of times that the tag reader  246  is used (e.g., only obtain the marker characteristic when the paint canister  284  is initially loaded into paint canister holder  282 ). 
         [0089]    It will be apparent that aspects, as described above, may be implemented in many different forms of software, firmware, and hardware in the implementations illustrated in the figures. The actual software code or specialized control hardware used to implement these aspects is not limiting of the description provided herein. Thus, the operation and behavior of the aspects were described without reference to the specific software code—it being understood that software and control hardware can be designed to implement the aspects based on the description herein. 
         [0090]    No element, act, or instruction used in the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. 
         [0091]    Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.