AU2005225149B2

AU2005225149B2 - Soil Characteristic Measuring Probe

Info

Publication number: AU2005225149B2
Application number: AU2005225149A
Authority: AU
Inventors: Arthur Henry Pickworth
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-11-29
Filing date: 2005-10-25
Publication date: 2008-04-10
Anticipated expiration: 2025-10-25
Also published as: ZA200509204B; AU2005225149A1

Description

00 O "SOIL CHARACTERISTIC MEASURING PROBE" SField of the Invention This invention relates to particulate material characteristic measuring equipment for use in measuring one or more characteristics within a body of particulate material within which the equipment is able to be introduced in a probe-like way (Ni and to a method of manufacturing such equipment. While not so limited the invention finds useful application in the field of measuring soil characteristics and 0in particular soil moisture at a variety of depths Background of the Invention It is well known that soil moisture content can be measured by way of capacitive measurement techniques. Probes used for performing this function known to the applicant have the disadvantage that they require meticulous fitment of the measuring electrodes along a holder to ensure accurate soil measurable characteristics at desired depths. Furthermore once assembled the electrodes and circuitry of such probes cannot be replaced without their damaging. It is, amongst others, an object of this invention to address one or more of these drawbacks.

Disclosure of the Invention Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

According to one aspect the invention resides in a particulate material characteristic measuring equipment for use in the enabling measurement of a characteristic at a known depth within a body of particulate material into which the equipment is to be located once in use, said equipment comprising: -2- 00

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0 at least one longitudinal circuit board incorporating suitable electrical circuitry to be able to provide a signal representative of the characteristic, at least two electrode elements that in conjunction with the circuit board form a measuring circuitry carrying carrier and are supported by the circuit board, the electrode elements connected into the electrical circuitry and arranged to in use provide an input into the electrical circuitry which is able to be operated upon by the circuitry to provide said signal, 0 the carrier being received within a closed tubular non-conductive holder (1 whereby at least a substantial portion of the electrode elements lie flush against the inner wall of the holder, wherein the electrode elements are physically supported by the carrier in linearly spaced relationship at known positions there along while at least a major part of each electrode element extends peripherally in close proximity adjacent the inner wall of the holder; said carrier being retained within the holder to resist relative linear and lateral displacement in response to the snug fitment of the board there along while the electrode elements extend relative to the board in way that counteracts their interference with the location of the board along the holder; the electrode elements being slidably received within the holder.

According to a preferred feature of the invention there are three electrode elements spaced substantially the same distance apart wherein in use the outer two electrode elements have the same polarity which is opposite to that of the central electrode element.

According to a preferred feature of the invention the holder has a cylindrical shape.

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SAccording to a preferred feature of the invention the electrode elements are in the form of laminar flexible sheet material having electrical conductive properties said electrode elements being received within the holder to conform to the curvature of 0the inner wall of the holder and lying flush with a portion if the internal wall of the holder to one or both sides of the carrier.

According to a preferred feature of the invention each electrode element extends to opposite sides of the carrier to be substantially symmetrical relative to the carrier with the length of each element being such that its free ends do not overlap within the holder.

According to a preferred feature of the invention the equipment provides for access to moisture content reflecting data by way of data storing and retrieving control circuitry carried by a control circuitry carrying carrier board adapted to receive and store the output from the electrical circuitry According to a preferred feature of the invention the control circuitry carrying carrier is in the form of a control circuitry carrying circuit board that is electrically connected to the circuit board and is accommodated at one end of the holder.

According to a preferred feature of the invention the equipment further comprises conducting means passing sealably through the wall of the holder and having an inner portion positioned to be in conducting contact with an electrode element and having an outer portion positioned to in use be in conductive contact with the particulate material body, said inner portion being configured to enable slidable movement of the electrode elements over the inner portion on movement of the carrier into or from within the holder.

According to a preferred feature of the invention the electrical circuitry is adapted to measure the moisture content of a body of particulate material.

According to a preferred feature of the invention the electrical circuitry is adapted to measure the temperature of a body of particulate material.

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0 According to a preferred feature of the invention the equipment further comprises a set of carriers located in an end to end relationship within the holder.

According to another aspect the invention resides a method of manufacturing a particulate material characteristic measuring equipment of the form as claimed at any one of the preceding claims, comprising the steps of inserting the carrier into the open end of the holder, said holder having an N open end and a closed end, wherein at least the major part of each of the 0 electrode elements comes to lie flush with at least portion of the inner wall of (Ni the holder, the electrode elements being caused to slide along the inner wall on insertion of the carrier into the holder, and sealingly closing the open end of the holder.

According to a preferred feature of the invention the electrode elements have the form of laminar flexible sheeting and extending to each side of the carrier, said method comprising the folding of the electrode elements on insertion into the holder to lie within the holder to conform to its inner wall wherein the free ends of the electrode elements do not overlap and are clear of the carrier.

According to a preferred feature of the invention the method further includes embedding the carrier within the holder with an non-conductive embedding substance.

According to a preferred feature of the invention the method further comprises prior to closing the open end of the holder, inserting the control circuitry carrying carrier board into the open end of the holder to abut the adjacent end of the carrier and connecting the control circuitry carrying carrier board to the electrical circuitry.

The invention will be more fully understood in the light of the following description of several specific embodiments.

00 Brief Description of the Drawings The description is made with reference to the accompanying drawings of which: SFigure 1 is a side elevation of an electrode and electrode interactive circuitry carrying carrier according to the embodiment; n Figure 2 is a side elevation of the electrode and electrode interactive circuitry C carrying carrier to the view of Figure 1; SFigure 3 is an isometric view of the electrode and electrode interactive circuitry carrying carrier of Figure 1; Figure 4 shows particulate material characteristic measuring equipment in the form of a probe, according to the embodiment, in a partially cut away side elevation, Figure 5 is a sectional view along line A-A of figure 4, Figure 6 shows the circuitry of the probe according to the embodiment in block diagram form, and Figure 7 stepwise shows the assembling of the probe, according to the embodiment, from its various components.

Detailed Description of the Drawings As shown at figures 4, 5 and 7 of the drawings the embodiment is directed to particulate material characteristic measuring equipment in the form of a particulate material characteristic measuring probe which can be used to measure at least soil moisture but when appropriate may also be used to measure soil temperature and soil conductivity. The measuring probe is generally indicated by reference numeral -6- 00

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0 Referring to Figures 1 to 3 the probe 10 includes a measuring circuitry carrying carrier 12 comprising measuring circuitry carrying circuit board 14 supporting three electrode elements in the form of electrodes 16 each of which is formed of laminar flexible sheeting. The electrodes 16 are located in axially spaced relationship along the longitudinal axis 18 of the board 14. The electrodes 16 extend laterally from each major face of the circuit board The electrodes 16 are in electrical contact with the circuitry of the circuit board 14 and extend from the opposite sides of the board 14 to define wing pairs 20. The board 14 and the electrodes 16 are accommodated within a holder in the form of a cylindrical tube S22 into which the carrier 12 is fitted. The tube 22 is closed off at one end and the insertion of the carrier 12 into the tube 22 is effected through its end 24 remote from its closed off end which end 24 is closed off on final assembly of the probe The probe 10 also includes a control circuitry carrying carrier in the form of a carrier board 26 carrying circuitry which serves in storing data and from which data is retrievable. The carrier board 26 is secured to the carrier 12 and is connected to the circuit board 14 by being plugged thereto via a circuit board end socket 28. The end 24 of the tube 22 is widened to accommodate the carrier board 26. In addition the probe 10 also includes an end cap 30 which is to be applied to the end 24 of the tube 22 to sealingly close the tube 22 to prevent the ingress of soil, moisture and other environmental elements into the tube 22. The retrieval of information stored by the carrier board 26 is facilitated via a coil 32 located to the outside of the cap 30 or otherwise via an electric plug (not shown) which is sealingly received through the cap. The carrier board 26 is formed with a battery seat 27 to which a battery is removably fitted for powering of the circuitry of the probe 10 once in use.

Referring more particularly to Figures 1 to 5 each electrode 16 is electrically secured to the board 14 by being received within a slot 34 formed in the circuit board 14. The location of the electrodes 16 within the respective slots 34 facilitates electrical contact with the circuit board 14. Such contact is ensured through its physical connection to the board 14 by typically a soldering process.

Each electrode 16 is thus in the form of a single length of laminar sheeting. The -7- 00

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0 opposed wings 36 extend to each side of the circuit board 14 to define each wing pair 20. Because of the nature of the material of which they are formed and the manner in which they are fixed to the board 14 the wings 36 extend symmetrically from the board 14. When the carrier 12 is inserted into the tube 22 the wings 36 will lie substantially flush against the inner wall of the tube 22 to either side of the carrier as is more clearly shown in Figure 5. The length of each of the wings 36 is such as to prevent their overlapping and being received between the edge 14.1 of the board 14 and the tube 22 when the carrier 12 is in position within the tube 22.

The electrodes 16 can take the form of laminar copper sheeting or copper 0 covered plastic sheeting.

The circuitry 38 of the circuit board 14 is conventionally arranged to enable the electromagnetic measuring of a soil characteristic which can comprise soil moisture but can also be to measure other soil characteristics. This is effected by way of the electrode elements 16.1 and 16.2. If the soil moisture is desired to be measured at a larger number of depths, a plurality of carriers 12 will be used of which the boards 14 are position in an end to end relationship and which are interconnected via complementarily arranged electrical connections (not shown).

As the electrodes 16 are situated at known positions along the board(s) the operative location of the probe 10 automatically ensures that the depth(s) of soil moisture measurement are known.

The probe 10 can also be formed to measure a conduction involving soil characteristic. To this effect the circuit board 14 is modified to cause the electrode 16.2 to also serve a conduction function in which it is thus in conduction communication with the soil once the probe 10 is operatively positioned. Such connection is effected via conducting means in the form of one or more conduction enabling elements (not shown) of which the inner ends are in electrical contact with the relevant electrode 16.2 while the outer ends are exposed for environmental conduction. The conduction enabling elements naturally pass sealably through the wall of the tube 22. The one or more conduction enabling elements are obviously strategically fitted to the tube 22 to cause them to come into electrical contract with the relevant electrode 16.2 once the circuit board 14 is properly installed within the tube. The inner end of the conduction enabling -8- 00 0 elements also project only slightly if at all into the tube 22 to prevent the catching of electrodes 16 during positioning of the carrier 12 down the tube 22. The circuitry 38 is in such a case is conventionally arranged to also accommodate such measurement.

When soil temperature is the soil characteristic to be measured the circuitry 38 can be conventionally arranged to achieve such measurement and even at a variety of depths.

The probe 10 can consequently be adapted to measure a variety of soil 6 characteristics. Its primary objective is, however, to measure soil moisture.

In referring to Figure 6 the circuitry 38 of the board 14 incorporates a capacitive measuring circuit 40 including the electrodes 16.1, a conductivity measuring circuit 42 including the electrodes 16.2 and the conduction supplementing electrodes and a temperature measuring circuit 44. The circuits 40, 42 and 44 report via a common measurement line to control circuitry 46 carried by the carrier board 26, that includes a frequency counting circuit 48, a processor 50 and a memory 52 together defining the logic of the probe 10. Particulars of the various circuits are not given as they already form part of the state of the art.

The length of the board 14 is selected to match the length of the tube 22 while its width ensures that it fits snugly and thus with very little lateral play along the length of the tube 22. Once the control circuitry carrying carrier board 26 is fitted to the board 14 and the tube 22 closed by way of the cap 30 the board 14 is also retained within the tube 22 against lengthwise displacement therein. Where a number of circuit boards 14 are located in an end to end relationship their combined length matches the length of the tube 22.

Especially but not exclusively where the probe 10 is intended for permanent installation the one or more carriers 12 can be embedded to the tube 22 by epoxy or a like resin substance.

-9- 00 SIn referring to Figure 7 manufacturing of the probe 10 is achieved by simply locating one or more carriers 12 down the tube 22 as shown in Figures 7(a) to During such fitting, and with particular reference to Figure 7(b) each electrode 16 is suitably folded on entering the tube 22 to enable its smooth ingress there into. Owing to their resilience each electrode 16 substantially snugly follows the curvature of the inner wall of the tube 22 once having passed into the tube 22 while smoothly sliding along the inner wall during progressive positioning of the carrier 12 into the tube 22 owing to the inside surface of the tube 22 being appropriately smoothened.

Referring to Figure 7(d) once the carriers 12 have been fitted to the tube 22 and the control circuitry carrying carrier board 26 is plugged to the board 14 via the socket 28 the tube 22 is closed off by way of the cap 30 to form the probe 10 as shown in Figure 7(e).

In use the probe 10 is simply inserted into a body of soil and the appropriate information is able to be retrieved from time to time via the coil 32 or via low powered radio communication (not shown) for further manipulation.

It is an advantage of the invention as specifically described that a probe that can accurately reflect the desired soil condition at one or more depths is manufacturable without requiring painstaking location of elements along a holder while its various components can easily be replaced except naturally in the case of permanent embedment.

The extent of thethe present invention is not to be limited in scope by any of the specific embodiments described herein. These embodiments are intended for the purpose of exemplification only. Functionally equivalent products, elements and methods are clearly within the extent of the invention as described herein.

Claims

1. A Particulate material characteristic measuring equipment for use in the enabling measurement of a characteristic at a known depth within a body of particulate material into which the equipment is to be located once in use, c said equipment comprising 0at least one longitudinal circuit board incorporating suitable electrical circuitry to be able to provide a signal representative of the characteristic, at least two electrode elements that in conjunction with the circuit board form a measuring circuitry carrying carrier and are supported by the circuit board, the electrode elements connected into the electrical circuitry and arranged to in use provide an input into the electrical circuitry which is able to be operated upon by the circuitry to provide said signal, the carrier being received within a closed tubular non-conductive holder whereby at least a substantial portion of the electrode elements lie flush against the inner wall of the holder, wherein the electrode elements are physically supported by the carrier in linearly spaced relationship at known positions there along while at least a major part of each electrode element extends peripherally in close proximity adjacent the inner wall of the holder; said carrier being retained within the holder to resist relative linear and lateral displacement in response to the snug fitment of the board there along while the electrode elements extend relative to the board in way that counteracts their interference with the location of the board along the holder; the electrode elements being slidably received within the holder -11 00 O S2. The particulate material characteristic measuring equipment as claimed in claim 1 in which there are three electrode elements spaced substantially the same distance apart wherein in use the outer two electrode elements have the same polarity which is opposite to that of the central electrode element.

3. The particulate material characteristic measuring equipment as claimed in claim 1 or claim 2 in which the holder has a cylindrical shape. S4. The particulate material characteristic measuring equipment as claimed in Sclaim 3 in which the electrode elements are in the form of laminar flexible N sheet material having electrical conductive properties said electrode elements being received within the holder to conform to the curvature of the inner wall of the holder and lying flush with a portion if the internal wall of the holder to one or both sides of the carrier. The particulate material characteristic measuring equipment as claimed in claim 4 in which each electrode element extends to opposite sides of the carrier to be substantially symmetrical relative to the carrier with the length of each element being such that its free ends do not overlap within the holder

6. The particulate material characteristic measuring equipment as claimed in any one of the preceding claims in which the equipment provides for access to moisture content reflecting data by way of data storing and retrieving control circuitry carried by a control circuitry carrying carrier board adapted to receive and store the output from the electrical circuitry.

7. The particulate material characteristic measuring equipment as claimed in claim 7 in which the control circuitry carrying carrier is in the form of a control circuitry carrying circuit board that is electrically connected to the moisture to the circuit board and is accommodated at one end of the holder.

8. The particulate material characteristic measuring equipment as claimed in any one of the preceding claims further comprising conducting means passing sealably through the wall of the holder and having an inner portion -12- 00 O 0 positioned to be in conducting contact with an electrode element and having an outer portion positioned to in use be in conductive contact with the particulate material body, said inner portion being configured to enable 0 slidable movement of the electrode elements over the inner portion on movement of the carrier into or from within the holder.

9. The particulate material characteristic measuring equipment as claimed in any one of the preceding claims in which the electrical circuitry is adapted to measure the moisture content of a body of particulate material. The particulate material characteristic measuring equipment as claimed in any one of the preceding claims in which the electrical circuitry is adapted to measure the temperature of a body of particulate material.

11. The particulate material characteristic measuring equipment as claimed in any one of the preceding claims comprising a set of carriers located in an end to end relationship within the holder.

12. A particulate material characteristic measuring equipment substantially as herein described with reference to the accompanying drawings.

13. A method of manufacturing particulate material characteristic measuring equipment of the form as claimed at any one of the preceding claims, comprising the steps of inserting the carrier into the open end of the holder, said holder having an open end and a closed end, wherein at least the major part of each of the electrode elements comes to lie flush with at least portion of the inner wall of the holder, the electrode elements being caused to slide along the inner wall on insertion of the carrier into the holder, and sealingly closing the open end of the holder. -13- 00

14. A method as claimed in claim 12 wherein the electrode elements as having the form of laminar flexible sheeting and extending to each side of the E carrier, said method comprising the folding of the electrode elements on insertion into the holder to lie within the holder to conform to its inner wall wherein the free ends of the electrode elements do not overlap and are clear of the carrier.. A method as claimed in claim 12 or claim 13 including embedding the carrier within the holder with an non-conductive embedding substance. S16. A method as claimed in any one of claims 12 to 14 as dependant from claim 6 or 7 that comprises prior to closing the open end of the holder, inserting the control circuitry carrying carrier board into the open end of the holder to abut the adjacent end of the carrier and connecting the control circuitry carrying carrier board to the electrical circuitry.

17. A method of manufacturing particulate material characteristic measuring equipment substantially as described with reference to the accompanying drawings.