AU2013204540A1 - Detecting moisture and/or termites. - Google Patents

Abstract

A method of detecting white ants within a structure is provided by placing switch means which switch to a detected mode in the presence of white ant infestation and utilising the switch means to activate an alarm. The switch means is suitably positioned in a wall cavity connected to an adjacent light or audible alarm to provide an external indication of the location of the termite infestation. 4 t4N

Description

1 TITLE Detecting moisture and/or termites. This invention relates to methods of and apparatus for monitoring a condition in a structure. BACKGROUND ART The presence of moisture in a structure of a building is a condition desired to be monitored, as moisture within a structure such as a dwelling can indicate a leak from an internal utility such as a water reticulation system or a water leak from the exterior of the structure. Leaks are also prevalent in wet areas such as locations for showers/bath, laundries, kitchen sinks and dishwashers. It is desirable to detect any such leak as soon as possible so remedial action can be taken. One of the difficulties associated with leaks is detecting the source of the leak as the apparent consequence of a leak may be horizontally and/or vertically remote from the source of the leak. In addition by the time a consequence of a leak becomes externally visible, a significant amount of damage may have been caused to the structure. Moisture in a structure can cause corrosion in metals, rot in timber and general water damage in panels and damage to a structure may be further caused by the necessity to perform a series of destructive investigations in order to locate the source of the leak. Also the presence of moisture in a timber structure is often a precursor to degradation of the structure by termites. While moisture in timber structures is often a precursor to termite infestation the presence of moisture may not be required for structural components of a structure to be degraded by termites. Such structural degradation can be minor and easily fixed, however if such infestation is left untreated a structure can be devastated by termite degradation of the structure. Thus the presence of destructive termites or the like is a further condition in a structure desired to be monitored. Because of the destructive nature of termites, many people monitor the land surrounding a structure in an effort to obtain an advanced warning of termite 2 presence and many arrangements of monitoring stations have been proposed for this purpose. This invention in one aspect aims to provide methods of and apparatus for detecting one or more condition in a structure desired to be monitored, such as a moist condition in a structure or the presence of termites or the like in a structure. These and other conditions to be monitored are hereinafter referred to individually or collectively as a desired condition. This invention in a further aspect aims to provide apparatus for monitoring for the presence of termites external to a structure. Other objects and advantages of this invention will hereinafter become apparent. SUMMARY OF INVENTION With the foregoing in view, this invention in one aspect resides broadly in a method of detecting a desired condition within a structure, including: providing switch means sensitive to a desired condition to be detected and which switches condition to a detected mode in the presence of the desired condition; placing the switch means within an internal cavity of a structure, and providing alarm means in communication with the switch means to provide an alarm when the switch means switches condition to its detected mode. In another aspect this invention resides broadly in a method of detecting a moist condition in a structure, including: providing moisture sensitive switch means which switches condition to a detected mode in the presence of moisture; placing the moisture sensitive switch means within an internal cavity of a structure, and providing alarm means in communication with the moisture sensitive switch means to provide an alarm when the moisture sensitive switch means switches condition to its detected mode.

3 In a further aspect this invention resides broadly in a method of detecting termites or the like in a structure, including: providing termite switch means which switches condition to a detected mode when termite activity is detected; arranging the switch means within an internal cavity of a structure, and providing alarm means in communication with the termite switch means to provide an alarm when the termite switch means switches to its detected mode. In any of the above methods, the alarm means may be a visible light and/or audible alarm assembly able to be switched on by switch means such as a moisture sensitive switch means or a termite switch means. The alarm means may be disposed externally of the structure and be arranged to communicate wirelessly or directly through electrical leads with the switch means whereby the visible light and/or alarm assembly will be activated when the switch means switches its condition to its detected mode. The visible light and/or alarm assembly may incorporate one or more LED lights or other low power consumption lights and an associated battery powered electronic circuit sensitive to the condition of the switch means which condition may be an open circuit or closed circuit state. Alternatively the alarm means may provide a signal sent through wires or wirelessly to a designated recipient such as a hard wired monitoring panel or wirelessly to a designated mobile phone or a remote monitoring station. The alarm means may be associated with a plurality of switch means which may be either or both moisture sensitive switch means and termite switch means. Preferably the alarm means is provided with the ability to identify which switch means is triggering an alarm so that a detected moist or termite infested location can be more readily identified. This may be achieved by the alarm means performing a preset sequential routine check of the switch means so as to identify and/or display the 4 condition of each switch means. Alternatively each switch means may have a unique characteristic identified by the alarm means to provide an indication of its location. The alarm means may be in continuous communication with the switch means so as to provide an instant alarm of a detected condition or it may be associated with a timer which provides communication with the switch means at regular intervals such as daily, weekly or monthly so as to maximise the battery life in a battery powered alarm version of this invention or to minimise the potential alarm signals that may be sent to a remote monitoring station. Alternatively a separate visible light and/or audible alarm assembly may be provided for each or a group of adjacent switch means such that the location causing the alarm can be more readily identified. In any of the above methods, each switch means may comprise a moisture sensitive switch means or a termite switch means or a combination of both types of switch means which could be separate switch means arranged in parallel. Alternatively the alarm means may incorporate separate alarms for separate switch means so that the alarm means may communicate with both a moisture sensitive switch means and a termite switch means and provide a unique alarm for a sensed moisture or termite infestation such as a green light for sensed moisture and a red light for sensed termite infestation. The switch means need not be an open circuit /closed circuit type switch and for example it could be a switch which exhibits a detectable change in resistance, capacitance or inductance or other detectable characteristic which varies in the presence of the desired condition to be monitored. In a simple form, apparatus for performing a method of this invention could comprise an open circuit /closed circuit type switch according to an aspect of this invention, wired in series with a power supply such as a battery or mains power and a bulb 5 which illuminates to provide the alarm when the circuit changes from open circuit to closed circuit by closing of the switch means. In a preferred embodiment which may be utilised in an existing structure or installed in a new structure each switch means communicates with a respective visible light and/or audible alarm assembly through a relatively short communication lead such that a location aperture may be formed in a wall, floor or ceiling for supporting the visible light and/or audible alarm assembly and whereby an alarm indication therefrom is visible or audible at the exterior of the wall adjacent the condition being sensed. Preferably, the switch means is adapted to be located internally of a structure by being inserted with its communication lead through the location aperture into a wall cavity. Preferably the length of the communication lead is sufficient as to enable the switch means to rest upon a horizontal portion of a structure as this is where moisture from a leak is most likely to accumulate or is readily accessible to termites. The location aperture may be formed in or adjacent a skirting board near floor level where moisture is most likely to accumulate and where a termite infestation of a structure is most likely to commence. A further advantage of this arrangement is that the visible light and/or audible alarm assembly and the switch means may be withdrawn from the structure through the location aperture to enable the switch means to be visually inspected such as on a regular basis when annual pest control/termite inspections are carried out or at other times as desired. The inspection may be for service purposes and to provide another indicator to an inspector as to the internal condition of the structure even if a moisture condition or a termite infestation has not been sensed. In a further aspect this invention resides in a moisture sensitive switch means suitable for use in any one of the methods or applications described above as well as for other uses and including a pair of electrical contacts separated by a detecting 6 member which normally forms an electrically non-conductive separator between the contacts but which provides an electrically conductive path between the contacts when the detecting member is or remains in the presence of a detectable amount of moisture. In its simplest form the detecting member is in the form of a dry electrically non-conductive joiner which becomes electrically conductive when moisture is absorbed thereby. The dry joiner may be impregnated with a suitable chemical to enhance its change from non-conductive to conductive state in the presence of moisture. Preferably the joiner is a wick which in contact with a liquid such as clean or contaminated water will absorb the liquid and become electrically conductive. The wick may be a flexible wick such as a fabric wick or it may be a rigid absorbent member made of cardboard for example. In a further aspect this invention resides in a termite switch means suitable for use in any one of the methods or applications described above as well as for other uses and including a pair of contacts biased to their closed position and held apart in open circuit condition by a termite consumable electrically non-conductive spacer which upon consumption of a sufficient portion thereof by termites or the like will allow the contacts to close indicating a closed circuit detected mode. In a further aspect this invention resides broadly in a method of monitoring a building for the presence of moisture or termites including: selecting a plurality of monitoring station locations in the walls of a structure adjacent the floor thereof; forming location apertures at the selected monitoring station locations through which switch means for detecting moisture and/or termites may be inserted into a wall cavity, and supporting externally accessible alarm means in the location apertures and 7 communicating with the alarm means so as to provide an external indication of moisture of termites in the adjacent monitoring station location. In a further aspect of this invention there is provided an external monitoring assembly having: a closed housing which may be supported in the ground whereby its interior is accessible to termites through an in-ground opening; supporting a switch means sensitive to the presence of termites within the housing and accessible to termites which enter the housing, and providing alarm means in communication with the switch means to provide an alarm when the switch means switches condition to its detected mode. Preferably the alarm means is an above ground light or a sound alarm supported by the housing. This invention may be applied to sensing moisture which may be present in the form of liquid such as in a cupboard below a sink or other kitchen or bathroom cupboard or in a room such as a switch room for a multistorey building which may be in a basement or a remote switch room such as for pumping or telecommunication apparatus which may be visited infrequently and which would benefit from having an early indication at a centralised monitoring station of the presence of moisture or termites. Accordingly the term internal cavity as used herein is to be understood as embracing a room or cupboard as well as a wall, floor, ceiling or roof cavity or the like. DESCRIPTION OF EMBODIMENTS In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate typical embodiments of this invention, wherein: Fig. 1 illustrates a typical form of moisture sensitive switch means; 8 Fig. 2 illustrates a typical form of termite switch means; Fig. 3 illustrates the termite consumable electrically non-conductive spacer supported between the electrical contacts of the switch; Fig. 4 illustrates a typical assembly of alarm means connected to a moisture sensitive switch means; Figs. 5 and 6 illustrates and provides details of another embodiment of the invention, and Fig. 7 illustrates an embodiment of this invention for exterior detection of termite infestation. The moisture sensitive switch means 10 illustrated in Fig. 1 comprises a detecting member 11 which is formed as a rectangular cardboard tab about 25mm long which has two spaced contacts 12 embedded therein, or otherwise connected thereto in a secure manner, which connect via respective leads 13 and 14 to a plug-in connector 15. The cardboard tab 11 is electrically non-conductive when dry so as to act as an insulator which electrically isolates the contacts 12 from one another. However when the tab 11 absorbs moisture, either from the air of from a puddle of water in which a portion of the tab 11 rests, it becomes conductive and bridges the circuit between the embedded contacts 12 so that the switch means 10 changes its mode from open circuit to closed circuit. The termite switch means 20 illustrated in Fig. 2 has two opposed metal spring contacts 21 and 22 supported in a body 23 such that their remote ends 24 are biased into contact with one-another. The body 23 has two spaced contacts 26 embedded therein, each in contact with a respective spring contact 21, 22 and a respective lead 29 and 30 which extends to a plug-in connector 31. The remote ends 24 of the spring contacts 21, 22 are formed as part-circular nesting portions 27, 28 which can be spread apart, as illustrated in Fig. 3 to secure a termite consumable 9 electrically non-conductive spacer 34 therebetween, suitably formed with complementary nesting portions 33 for secure retention between the spring contacts 21, 22. For this purpose the spacer 34 illustrated in Fig. 3 has corresponding part-circular indentations 35 at each side to accommodate the part-circular nesting portions 27, 28 at remote ends 24. The nesting contacts 27, 28 are normally closed but are held open by the spacer 34, awaiting at least partial consumption by termites, allowing the contacts 27, 28 to spring back into contact with one another causing the switch 20 to revert to its closed circuit detected mode. An opening may be formed through the spacer 34 at the indentations to assist closing of the contacts upon consumption of the surrounding spacer. Furthermore each complementary nesting portion 27, 28 may be provided with a small inwardly directed projection, both of which are brought firmly together by their spring support. This will minimise the area between contact points and thus assist in forming electrical contact therebetween when some surrounding spacer 34 may remain unconsumed. The switch means 20 may also utilise an absorbent spacer as per the switch illustrated in Fig. 1 in lieu of the consumable termite spacer for moisture sensing duties. Further, the switch means of Fig. 1 may also be effective in monitoring for the presence of termites and the like insects as the waste from the termites which is deposited on the tab may act as a conductive bridge between the contacts. Both of the switches 10 and 20 can be used singularly or together with an alarm means 40 as illustrated in Fig. 4, which communicates with the switches 10, 20 through leads 41 to a complementary plug-in connector 42. In this embodiment the alarm means 40 utilises LED lights 43 in a faceplate 45 and a suitable solid state circuit encapsulated in the threaded body 46 for switching the lights 43 depending 10 on the state of the or a switch 10, 20. A battery pack 47 for the LEDs and the control circuit is also connected to the body 46. In use, the alarm means 40 is adapted to be screwed into a complementary aperture formed in a wall panel or skirting board for example, after the switches 10, 20 and battery pack 47 have been fed through the complementary aperture into an internal cavity of the wall. The solid state circuit may include timing means such that the switches are monitored only at desired intervals and for controlling the operation of the LEDs which may be caused to flash in the case of a detected condition such as the presence of moisture or the presence of termites. Termites may also be detected by other forms of switch means such as a noise switch adapted to change mode to a detected mode upon detection of the characteristic noise made by active termites in a structure or by a gas detector for detecting C02 and/or methane which are produced by an active termite infestation. In a hardwired system installed at the time of building the structure, the alarm means will be powered by the mains electrical supply, preferably at a reduced voltage for safety, or they could be solar powered. The alarm means may provide a warning light for the homeowner and or electronic notification to an internal switchboard and further notification to a designated pest controller through the internet or phone system. The hard wired system may utilise alarm means similar to that illustrated in Fig. 4 located adjacent the floor so as to provide a visual indication of the location of a monitored condition. The exposed face plate of the alarm means may also provide night lighting at floor level for ease of movement around dark passages. The spacer 34 could also be formed from an absorbent material which is attractive to termites and the like as an edible material so that the switch acts both as a moisture sensitive switch and a termite sensitive switch. In the embodiment 50 illustrated in Figs. 5 and 6, the alarm means are constituted by LED lights 51 supported by a push-in housing 52 which is retained in a suitable 11 location aperture 53 formed in a wall panel 54 above the skirting board 55 and the switch means 56 is connected thereto by a short flexible lead 57 which will enable the switch means 56 to fall down from the housing to rest upon the bottom plate 58 where moisture which enters the wall cavity 59 is likely to accumulate and where termite attack of the wall structure is likely to commence. The electronic circuit controlling the LED lights and or the battery for powering same is supported in the body 60 of the switch means 56 where a pair of contacts 61, 62 connected to the electronic circuit are urged toward one another for closing by coil springs 63. As illustrated the contacts 61, 62 are urged to their open position buy a insulating spacer 65 formed of material which termites will eat such as timber so that in use when the termites eat the spacer 65 the contacts close and actuate the alarm. This could be timber or cellulose insert soaked in Termidoor. In this embodiment there are three Led lights, a green LED to indicate an ultra low voltage drop across the contacts 61, 62, a red LED to indicate a low or no voltage drop across the contacts, indicating an alarm condition and a yellow LED to indicate a low battery or fault condition. The termite alarm monitoring assembly 70 illustrated in Fig 7 is formed for support partially buried in the ground at an exterior location. The assembly 70 utilises a plastic tube-like housing 71 having a closure cap 72 at its upper end which supports a battery 73 and the electronic circuit 74 for powering the LED lights 75 as well as a termite switch 76 of the type illustrated n Fig. 5 which hangs from the circuit 74 to rest upon a lower pointed timber cap 77 which is disposed underground in use and which has passages 78, 79 therein through which termites can enter the housing 71 through a below ground location and access the switch 76. In use, when the contacts of the switch 76 are closed as a result of termites eating away the spacer or when a low voltage condition is sensed by partial bridging of the switch contacts with termite waste, an alarm condition is monitored and the Led 12 lights 75 are switched on by the electronic circuit 74. The LED lights may be caused to flash or display continuously and provide an indication of termites in the housing 71, especially at night when the lights will be readily observed. The cap 72 may be unscrewed at any time to enable the battery and/or switch to be serviced and to enable a visual inspection of the interior of the housing 71 to be carried out. The cap may support solar cells for charging the battery It is envisaged that the devices of this invention could be used in-conjunction with the Pest Control Industry where termite barriers are installed, in a post construction method for eradicating live termites from a dwelling. Pest Technicians will be able to install the devices for an ongoing monitoring system for both the homeowner and the Pest Control Company. Similarly builders could utilize the devices to monitor the success of a repair to a shower, bath or roof void in a new or existing dwelling. A major advantage afforded by this invention is the ability to be provided with an early warning of a leak or termite infestation as well as a good indication as to the location of the leak. When used in high-rise buildings this invention may enable the floor at which the leak originates to be identified. If a leak only becomes visible in a lower floor this invention has the potential to indicate a leak at an upper level which may prevent the search for the leak being done progressively floor by floor. The switch means of this invention may also be used in other applications, such as the bilge of a boat where corrosion is a problem. Utilising a switch means according to this invention which can be inspected and replaced simply and cheaply if necessary may provide more reliability than currently available switches. The termite sensing means of this invention may also be used out of doors to monitor for termite infestation in a yard. The outdoor version could be battery or solar powered and be provided with a wireless transmitter of known type for very localised transmission such as is used for actuating roller doors, gates and the like or it could be provided with interrogation means such that a pest controller with a 13 suitable device could interrogate the devices in a yard in a regular check for termite infestation. Of course the indoor versions could also be similarly equipped so they could be installed for on the spot interrogation without the need to have any visible indication of the switch mode or its installation. It will of course be realised that the above has been given by way of illustrative example of this invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is defined in the appended claims.

Claims (10)

1. A method of detecting a desired condition within a structure, including: providing switch means sensitive to a desired condition to be detected and which switches condition to a detected mode in the presence of the desired condition; placing the switch means within an internal cavity of a structure, and providing alarm means in communication with the switch means to provide an alarm when the switch means switches condition to its detected mode.

2. A method of detecting a moist condition in a structure, including: providing moisture sensitive switch means which switches condition to a detected mode in the presence of moisture; placing the moisture sensitive switch means within an internal cavity of a structure, and providing alarm means in communication with the moisture sensitive switch means to provide an alarm when the moisture sensitive switch means switches condition to its detected mode.

3. A method of detecting termites or the like in a structure, including: providing termite switch means which switches condition to a detected mode when termite activity is detected; arranging the switch means within an internal cavity of a structure, and providing alarm means in communication with the termite switch means to provide an alarm when the termite switch means switches to its detected mode.

4. A method as claimed in any one of the preceding claims, wherein the alarm means is a visible light and/or audible alarm assembly able to be switched on by a moisture sensitive switch means or a termite sensitive switch means.

5. A method as claimed in any one of the preceding claims and including connecting the switch means to a respective visible light and/or audible alarm 2 assembly through a relatively short communication lead such that a location aperture may be formed in a wall, floor or ceiling for supporting the visible light and/or audible alarm assembly and whereby an alarm indication therefrom is visible or audible at the exterior of the wall adjacent the condition being sensed.

6. A moisture sensitive switch means suitable for use in any one of the methods defined in claim 1 to 5 and including a pair of electrical contacts separated by a detecting member which normally forms an electrically non-conductive separator between the contacts but which provides an electrically conductive path between the contacts when the detecting member is or remains in the presence of a detectable amount of moisture.

7. A termite switch means suitable for use in any one of the methods defined in claim 1 to 5 and including a pair of contacts biased to their closed position and held apart in open circuit condition by a termite consumable electrically non-conductive spacer which upon consumption of a sufficient portion thereof by termites or the like will allow the contacts to close indicating a closed circuit detected mode.

8. A method of monitoring a building for the presence of moisture or termites including: selecting a plurality of monitoring station locations in the walls of a structure adjacent the floor thereof; forming location apertures at the selected monitoring station locations through which switch means for detecting moisture and/or termites may be inserted into a wall cavity, and supporting externally accessible alarm means in the location apertures and communicating with the alarm means so as to provide an external indication of moisture of termites in the adjacent monitoring station location.

9. An external monitoring assembly having: a closed housing which may be supported in the ground whereby its interior 3 is accessible to termites through an in-ground opening; supporting a switch means sensitive to the presence of termites within the housing and accessible to termites which enter the housing, and providing alarm means in communication with the switch means to provide an alarm when the switch means switches condition to its detected mode.

10. Detecting methods and/or apparatus substantially as hereinbefore described with reference to the accompanying drawings.