Since restaurants often make much of their profits on drinks, it is critical for servers to offer refills in a timely fashion. We propose wireless liquid level sensing glassware to aid in this task. Specially instrumented glassware detects fluid levels via a high-resolution capacitance measurement. A coil embedded in the table inductively couples power to the glasses, and provides a path for data exchange. Our prototype glass uses a standard microprocessor and a small number of passive components, making it extremely inexpensive.
Background & Objective: It is a common problem ÃƒÂ¢Ã¢â€šÂ¬Ã¢â‚¬Å“ you are in a bar or restaurant with your drink almost gone and you are desperately hoping that one of the staff will notice and offer you a refill. Sometimes they do, and sometimes they donÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢t. If they donÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢t, you leave a little less happy with your experience and are less likely to return, the waiter or waitress gets a lower tip, and the restaurant has lost the chance to sell you a drink. Meanwhile, thirsty customers may stand waiting at the door for lack of a table. Everyone loses. It is such a little thing; yet doing it right or wrong can easily make the difference between economic success or failure. Ãƒâ€š Ãƒâ€š By using a combination of RFID and capacitance sensing technologies, we are able to achieve these properties.
Dietz, P.H.; Leigh, D.L.; Yerazunis, W.S., “Wireless Liquid Level Sensing for Restaurant Applications”, IEEE Sensors, Vol. 1, pp. 715-720, June 2002 (IEEE Xplore, TR2002-021)
Modification Date: July 7, 2008