Water leak detection

A method and device for detecting water leaks is disclosed. The method and device comprise an odorant in a water soluble barrier. The odorant and water soluble barrier can be contained in a housing and placed in a location where water leakage can occur. In the method and device described herein, leaking water dissolves the barrier and releases the odorant into the atmosphere thereby alerting persons to the presence of water as a result of a leak.

FIELD OF INVENTION 
The present invention relates to the detection of water leaks generally and 
in particular to a method and device for detecting water leaks by the use 
of an odorant. 
BACKGROUND OF THE INVENTION 
Property loss due to water damage costs homeowners and businesses billions 
of dollars every year. Common water damage happens as a result of plumbing 
problems, rain water and flooding. For example, water damage can occur due 
to problems with water heaters, boilers, dishwashers, sump pumps, faucets, 
washing machines, pipe fasteners, air conditioners, water filters, 
dehumidifiers, toilets, tanks, showers, pipe breaks, leaky roofs and 
gutters, broken windows, sinks, etc. In many instances, the leaks can be 
small but, unless detected, can escalate and add up to substantial 
property losses in both the home and business environment. 
There are several methods and devices currently in use for the detection of 
water leaks. These devices are based on the use of electronic alarms and 
circuitry to detect water. See for example U.S. Pat. No. 5,539,383. There 
are also known to be fire alarm systems which can be used to detect the 
presence of water. These devices, however, can be expensive. Additionally, 
such devices have the disadvantage of running on electricity or batteries 
which must be monitored by the user. None of these methods or devices seem 
to describe the instant invention as claimed. 
Therefore, there remains a need for a water leak detection method and 
device which is simple, inexpensive and easy to use. The present invention 
constitutes such a method and device for detecting water leaks by use of 
an odorant. 
SUMMARY OF THE INVENTION 
Objects and advantages of the invention are set forth below. 
It is a principle object of the present invention to provide a novel method 
and device for detecting water leaks which is simple, effective, 
inexpensive and easy to use. 
It is a further object of the present invention to provide a novel method 
and device for alerting people to water leaks before significant water 
damage occurs. 
Accordingly, the method and device for detecting water leaks of the present 
invention comprises the release of an odorant by the presence of water. 
The method of the present invention comprises detecting water leaks by 
providing an odorant in a water soluble matrix or barrier such that water 
leakage causes the water soluble matrix or barrier to dissolve releasing 
the odorant and alerting the appropriate people of the presence of water. 
The water leakage detection device of the present invention comprises the 
enclosure of an odorant in a water soluble matrix or barrier within a 
housing such that when water enters the housing and contacts the matrix or 
barrier, it dissolves the water soluble barrier releasing the odorant and 
thereby alerting the appropriate people of the presence of water.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention relates to both a method and device for detecting 
water leaks by releasing a detectable odor. 
The method of the present invention is the release of an odorant by water 
wherein the odorant is retained by a water soluble matrix or barrier. 
Several systems for use in this method are described. One embodiment of 
the present invention includes a physical mixture of the odorant in a 
water soluble wax or polymer. Another embodiment of the invention is an 
encapsulate that surrounds an odorant with a water soluble wall. The 
production of these encapsulates are by processes generally known in the 
art including, for example, processes such as spray drying, granulation 
and coacervation. Such encapsulates can therefore be in granular or pellet 
form. In another embodiment of the present invention, the material that is 
contained in the water soluble matrix or barrier is transformed into an 
odorant upon contact of the material with water. A further embodiment of 
the present invention includes an odorant retained inside a water soluble 
film. The creation of these embodiments is generally known by those 
skilled in the art. 
In the method of the present invention, any one of the above-described 
embodiments are placed in a location where water leakage may occur. 
Examples of such locations include unattended, not observable or difficult 
to access areas such as, for example, bathrooms, basements, sinks, 
dishwashers, hot water heaters, unit boilers, water tanks and any place 
near a pipe. Water leakage causes the soluble matrix or barrier to 
dissolve releasing the odorant. The odorant will alert persons that water 
is present allowing for corrective measures to be taken before serious 
water damage occurs. 
Many water soluble material can be used in the present invention. Examples 
of such water soluble materials include polyvinyl alcohol, gelatin, methyl 
cellulose and starch. The water soluble matrix or barrier should be 
resistant to humidity. 
The odorant of the present invention can be selected from the many 
available. Preferred odorants of the present invention are those that have 
low detection thresholds. Most preferred odorants of the present invention 
are those that have a recognizable distinctive and/or unpleasant odor. The 
odorant should be stable over a long period of time and be resistant to 
humidity. The odorant can be a single material or a mixture. The odorant 
should preferably have one component that has a high vapor pressure so 
that it diffuses rapidly when released by water. The odorant should also 
not be too water soluble so that it can be released and not dissolved by 
the water. Such a mixture may also have some low vapor pressure materials 
that will evaporate slowly so that if the area of the water leak is 
unoccupied or unattended for a few or several days, an odor will still be 
apparent. Accordingly, in a further embodiment of the present invention, 
the odorant can be time released. 
Examples of odorants include fragrance materials such as citronellal, lime 
oxide, alpha pinene and eucalyptol and odorants that have strong distinct 
and/or unpleasant odors such as mercaptans, thiomenthone and methional. 
Other odorants, such as peppermint, may be used. Further odorants can be 
found in Perfume and Flavor Chemicals (Aroma Chemicals) by Steffen 
Arctander, Steffen Arctander's Publications, Las Vegas, Nev., 1969. 
The following examples serve to further illustrate the inventive concept 
and are not intended to be construed as limitations on the invention, 
which is defined by the claims. 
EXAMPLE 1 
A 10% (w/w) dispersion of gelatin in water at 40.degree. C. is prepared and 
added to it with continuous stirring is an equal weight of a water 
insoluble low threshold fragrance material, dibutyl sulphide A 20% (w/w) 
sodium sulphate solution is added to make up 50-60% of the final total 
volume. The system is cooled to 5.degree. C. Glutaraldehyde is added until 
capsules form. The resulting capsules are washed and dried. One capsule is 
dropped in a pint of water and left in a closed room for half an hour. On 
opening the door a strong distinctive repulsive smell is evident. 
EXAMPLE 2 
Example 1 is repeated using citronellal as the fragrance materials and a 
strong green citrusy odor is evident. 
EXAMPLE 3 
An aqueous mixture of 2.5% (w/w) gelatin and 2.5% gum acacia are prepared. 
To the gelatin solution 5% (w/w) of skatole is added and emulsified. An 
equal volume of the gum acacia solution is added with continuous stirring. 
The temperature of the system is maintained above 35.degree. C. The pH is 
adjusted to 3.8-4.3 with continuous mixing. The system is cooled to 
5.degree. C. and glutaraldehyde is added adjusting the pH to the above 
range until capsules form. The capsules are washed and then dried. 
One capsule is dropped in a pint of water and left in a closed room for 
half an hour. On opening the door, a strong fecal animal smell is noted. 
EXAMPLE 4 
The process in example 3 is repeated using 2-thienyl mercaptan. A very 
strong burnt caramel sulphurous odor is easily detected. 
The present invention also includes a device for housing the water leak 
detection system. Such a device is a housing which can contain the water 
soluble barrier and odorant described above. The housing must have 
openings allowing for water to reach the water soluble barrier and odorant 
described above. The housing can be simple and small and be placed near 
any area which may be subject to water leakage. 
In one embodiment of the present invention, the housing can be a plastic 
unit containing the water soluble barrier and odorant described above. In 
this embodiment, holes are placed throughout the housing. Leaking water 
contacts and permeates the housing such that the water soluble barrier 
dissolves releasing the odorant into the atmosphere. In this embodiment, 
the housing should set flush to the ground so that any leakage can be 
detected rapidly. Other housings can be devised in accordance with 
knowledge of those skilled in the art such that designs can be adapted to 
fit specific areas or tasks. 
In another embodiment of the present invention, the housing can be 
contained in a larger adhesive shell to prevent child or pet ingestion. In 
another embodiment of the present invention, the device can be without a 
separate housing, i.e. pellets or granular in nature which can be easily 
spread around in a location subject to water leakage. In a further 
embodiment of the present invention, the housing can be a mesh sachet, 
which may or may not be weighted. In a further embodiment of the present 
invention, the odorant is embodied in a water soluble film which can be 
directly applied to an area subject to water leaks. For example, a water 
soluble film, adhesive coated or not, containing the odorant can be 
wrapped around pipes such that a small leak will release the odorant. 
Alternatively, a water soluble coating containing the odorant can be 
devised such that a pipe can be dipped in the mixture thereby coating the 
pipe. 
The above described embodiments are intended, by way of example, to 
illustrate the principles of the invention but not to limit the scope of 
the claims. Various other embodiments and modifications to these 
embodiments may be made by those skilled in the art without departing from 
the scope of the following claims.