Abstract:
Described are clips for collecting sensors into multi-sensor arrays for insertion into wells and the like. The clips are adapted to easily receive the sensors and provide a lock for securing the sensors once installed. The clips can be adapted for use with elements other than sensors, in particular for applications in which a number of relatively elongated members are to be secured in parallel.

Description:
BACKGROUND 
   Environmental consciousness and newly promulgated laws place ever-increasing emphasis on maintaining water quality in lakes, streams, groundwater, and industrial effluents. Due to this emphasis, there is a growing market for systems capable of monitoring various physical and chemical properties of water resources. Parameters of interest include conductivity, dissolved oxygen concentration, oxidation-reduction potential (ORP), pH, temperature, and depth, to name just a few. 
   Surface-water data is typically collected using immersed sensors. Collecting groundwater data can be more troublesome, often requiring that wells be drilled for sensor insertion. Drilling wells is expensive, but the cost can be reduced by minimizing bore diameter. Sensors for use in wells are therefore made to have relatively small diameters. For a detailed description of typical sensors, see U.S. Pat. No. 6,305,944 to Henry et al., which is incorporated herein by reference. 
   It is often desired to simultaneously monitor two or more water-resource parameters or to measure the same parameter with a number of redundant sensors. Such applications sometimes require a number of sensors be collectively inserted into a single well. Due to the desire to maintain a small well diameter, sensors are often staggered along a well bore for multi-sensor applications. Unfortunately, staggered sensors may be monitoring materially different water samples. Moreover, the water in some wells may be too shallow to submerge multiple sensors arranged in series. There is therefore a need for a means of introducing a plurality of sensors into narrow-bore wells. 

   
     BRIEF DESCRIPTION OF THE FIGURES 
       FIG. 1A  depicts a sensor  100  that can be combined with like sensors to create multi-parameter systems for monitoring groundwater in small-diameter wells. 
       FIG. 1B  depicts a clip  130  adapted to bind together three sensors  100  of the type depicted in  FIG. 1A . 
       FIG. 1C  depicts a multi-sensor array  160  that includes three sensors  100  arranged substantially in parallel. 
       FIG. 2A  depicts a lock  200  for insertion into respective compression reliefs  145  of a pair of clips  130 . 
       FIG. 2B  depicts a multi-sensor system  220  similar to system  160  of  FIG. 1C  but with three locks  200  inserted into compression reliefs  145  to secure sensors  100  within respective retaining bays  140 . 
       FIG. 2C  depicts a side view of system  220  of  FIG. 2B . 
       FIG. 3  depicts sensor system  220  of  FIG. 2C  inserted into a well  300 . 
       FIG. 4  depicts another embodiment of a clip  400  adapted to support three sensors. 
       FIG. 5  depicts a clip  500  adapted to support four sensors. 
       FIG. 6  depicts a clip  600  that supports six sensors. 
       FIGS. 7A and 7B  depict a clip  700  that can be used in conjunction with another identical clip to support seven sensors. 
       FIG. 8  depicts a two-sensor clip  800  in which the compression relief  805  is semi-circular. 
       FIG. 9  depicts a clip  900  that can be used to place three sensors in a planar array. 
       FIG. 10  depicts a clip  1000  adapted to host an array of six sensors arranged in two parallel planes. 
       FIG. 11  depicts a clip  1100  that include differently sized retaining bays. 
   

   DETAILED DESCRIPTION 
     FIG. 1A  depicts a sensor  100  that can be combined with like sensors to create multi-parameter systems suited for monitoring groundwater in small-diameter wells. Sensor  100  is representative of a number of substantially cylindrical sensors used for e.g. sensing temperature, depth, pH, and ORP of groundwater. Sensor  100  conventionally includes a cable housing  105  that provides a secure, watertight connection between a cable  110  and a sensor body  115 . The opposite end of sensor body  115  connects to a sensor housing  120 . Sensor body  115  houses the electronics necessary to drive signals generated by a sensor in housing  120  out onto cable  110 . Sensor  100  includes a pair of grooves  125 , the widths of which are designed to accommodate a clip, described below, for securing sensor  100  to one or more other sensors. One or both of grooves  125  may be incorporated into body  115 . 
     FIG. 1B  depicts a clip  130  adapted to bind together three sensors  100  of the type depicted in  FIG. 1A . Clip  130  includes three retaining elements  135  that define between them three retaining bays  140 . Each retaining bay  140  has a diameter D that is somewhat greater than an opening E defined between adjacent pairs of retaining elements  135 . Diameter D is selected to snugly accommodate grooves  125  of sensor  100 . 
   In some embodiments, threads in sensor body  115  mate with opposite threads on sensor housing  120 . The width of the groove  125  defined between housing  120  and body  115  can therefore be altered to accommodate clip  130 . In one such embodiment, screw-tightening housing  120  into body  115  with clip  130  installed compresses clip  130  between housing  120  and body  115  to provide a secure mechanical connection, and screw-tightening housing  120  into body  115  without clip  130  installed eliminates the groove. Grooves  125  differ in  FIG. 1A  to show two examples, but are typically of the same type. 
   Compression reliefs  145  ease the compression of respective retaining elements  135  to admit sensors  105  into retaining bays  115 . Each compression relief  145  includes a pair of lock-retaining tabs  155 , the purpose of which is explained below in connection with  FIGS. 2A through 2C . Clip  130  is sufficiently rigid so sensors  100  snap into place, in the manner depicted in  FIG. 1C , to form a multi-sensor system  160  that includes three sensors  100  arranged substantially in parallel. In one embodiment, clip  130  is Delrin™ plastic, but other materials are also suitable. 
     FIG. 2A  depicts a lock  200  for insertion into respective compression reliefs  145  of a pair of clips  130  ( FIGS. 1B and 1C ). When installed, lock  200  reduces the flexibility of flexible retaining elements  135 , and consequently secures sensors  100  within retaining bays  140 . Lock  200  includes a pair of slots  210  and holes  215 . Slots  210  mate with respective compression reliefs  145 : holes  215  engage lock retaining tabs  155  to secure lock  200  within compression reliefs  145 . Lock  200  includes tapered ends that ease insertion and extraction of sensor system  220  into wells, tanks, and the like. 
     FIG. 2B  depicts a multi-sensor system  220  similar to system  160  of  FIG. 1C  but with three locks  200  inserted into compression reliefs  145  to secure sensors  100  within respective retaining bays  140 .  FIG. 2C  depicts a side view of system  220  of  FIG. 2B  with one of locks  200  omitted to better depict a pair of reliefs  145 . 
     FIG. 3  depicts sensor system  220  of  FIG. 2C  inserted into a well  300 . Well  300  includes a water level  310  that is too low to accept a plurality of sensors arranged in series along the depth of well  300 . Multi-sensor system  220  connects to an aboveground receiver  315  via a sturdy cable  320 . 
     FIGS. 4–10  depict various alternative clip embodiments for securing multiple sensors.  FIG. 4  depicts an embodiment of a clip  400  adapted to support three sensors. Clip  400  includes a hole  405  that allows water to drain out of the cavity defined between three sensors. Hole  405  may be advantageous in embodiments in which the sensors tightly contact one another to minimize the collective diameter, and thus create a more or less sealed compartment between them. Hole  405  may also be used to mount a collection of sensors to a rod or cord, or to provide an avenue for a cable. 
     FIG. 5  depicts a clip  500  adapted to support four sensors. Of interest, clip  500  includes only a single compression space  505  that maybe provided with a lock (not shown) of the type discussed above. Provided clip  500  is sufficiently resilient, clip  500  can be assembled into a multi-sensor system by snapping sensors into three retaining bays  510 , leaving one retaining bay adjacent compression relief  505  for the last sensor. Compression relief  505  can be locked after inclusion of the last sensor. 
     FIG. 6  depicts a clip  600  that supports six sensors. Clip  600  includes a compression relief  605  that differs in shape from the compression reliefs depicted above to show that the compression relief used in a given embodiment can be adapted as desired. In this example, a lock  610  snaps into relief  605 . Lock  610  is also depicted in side-view (upper-most depiction). 
     FIG. 7A  depicts a clip  700  that can be used in conjunction with another identical clip to support seven sensors without increasing the collective multi-sensor-system diameter beyond that provided by clip  600  of  FIG. 6 . Two clips  700  can be combined as depicted in  FIG. 7B  to form a seven-sensor clip  710 . The pair of clips  700  share one groove  125 . The portions of clips  700  that do not overlap when forming clip  710  can be made twice as thick as the overlapping portions, if desired. 
     FIG. 8  depicts a two-sensor clip  800  in which the compression relief  805  is semi-circular. 
   In some cases arrays of sensors are not inserted into a well, but might instead be placed e.g. on the bottom of a lake, pond, or stream. Planar sensor arrays may therefore be preferred in some embodiments.  FIG. 9  depicts a clip  900  that can be used to place three sensors in a planar array. A locking mechanism  905  is attached to clip  900  via a flexible member  910  to keep the locking mechanism and clip together when clip  900  is unlocked. Sensors  100  should be loaded left-to-right, leaving the sensor bay adjacent the compression relief for last. 
     FIG. 10  depicts a clip  1000  adapted to host an array of six sensors arranged in two parallel planes. Clip  1000  includes a single compression relief  1005 . Clip  1000  should be loaded left-to-right, leaving one of the retaining bays adjacent compression relief  1005  for last. 
     FIG. 11  depicts a clip  1100  that includes differently sized retaining bays. Such embodiments may be desired for use with different types of sensors or to attach one or more sensors to e.g. a support. For example, a collection of sensors may be attached to a support rod adapted to position the sensors at an appropriate position within an effluent well. Though not shown, the retaining bays may also be of shapes other than semicircles and may be adapted to secure elongated elements having non-circular cross-sections. 
   While the present invention has been described in connection with specific embodiments, variations of these embodiments will be obvious to those of ordinary skill in the art. For example, the clips described above can be used secure elements other than sensors, such as cables, poles, pipes, and electrical conduits. Therefore, the spirit and scope of the appended claims should not be limited to the foregoing description.