This invention relates to a humidity sensing system for determining when the humidity in a storage container for articles is outside a predetermined range.
The increasing usage of tobacco products, notably cigars, by the general population has generated interest in maintaining the tobacco products in a proper storage environment. The enjoyment of a cigar depends in part on its history. Should the conditions of storage be too moist or too dry, the value of the cigar is diminished often to the point of becoming worthless. As the popularity of use increases, the demand for tobacco products containing specific types of premium tobacco has caused prices to escalate to the point where a box of fine cigars or a container of blended rare pipe tobaccos represent a substantial sum of money. Unlike cigarettes which are normally rapidly consumed, the cigar and pipe user typically buys a quantity of product that is intended to last for an extended period of time. Consequently, attention is directed to the storage conditions of these premium tobacco products.
The maintenance of the moisture content in the ambient environment is the primary concern of the consumer in maintaining the product quality. Since the consumer is unlikely to be in a position to dedicate the time, resources and space required to duplicate the special rooms used by tobacco merchants to control temperature and moisture, the need has arisen for a practical humidity sensing system which is reliable, much less elaborate than the merchant's facility and suitable for home or office use.
One approach to the provision of a user storage container for tobacco products utilizes containers which include water chambers or storage components for water. Means for releasing moisture over a period of time are included as a structural feature of the container. This type of device does not provide an indication of the actual humidity within the container and ceases to function at all when the water-containing element has dispensed its water. One type of storage container for tobacco which relies on the use of a water reservoir extending into the container is shown in U.S. Pat. No. 5,556,579. The ambient moisture supplied to the air within the container of the disclosed device is controlled through mechanical adjustment of shutters overlying passages in the water reservoir. The effectiveness of the arrangement is only determined when the user opens the container to withdraw a stored product. Thus, these devices lack any means to provide an external indication of the true state of the moisture content within the container.
An electronic moisture meter for use in measuring the moisture content of tobacco during processing is disclosed in U.S. Pat. No. 4,114,090. The tobacco passes through or near a double plate capacitor, the capacitance of which is a function of the moisture content of the tobacco. The frequency of an oscillator varies with the changes in capacitance. A frequency to voltage converter is used to generate a digital read out signal for display of the moisture content of the tobacco being processed. The meter is intended for use in a process environment and thus employs relatively large size capacitance as well as being coupled to an external power supply.
Accordingly, the present invention is directed to a humidity sensing system which is suitable for use in monitoring moisture in a container for tobacco products, typically cigars. In addition, the invention operates to sense and transmit an alarm signal from the container should the moisture level move outside a predetermined range. Thus, the system within the container operates from battery power. The operation of the sensor is intermittent to extend the service period of the power source within the container. The sensor is dimensioned to be conformably received in a cigar box for use in connection with an external alarm signaling device.