Reed sensors and Magnet sensors in Commercial Coffee Machines
Commercial coffee and tea vending machines are built with durability in mind as the number of cups served per day could exceed hundreds. When such large volumes of orders are filled, it is important that that accuracy of the dispensed volume of beverage be correct as a small error could result in spillage and wastage of raw materials. To dispense the exact quantity of coffee, tea, water or milk, such machines need to measure the volume by filling up an internal reservoir and then use this reference to fill cups. This is accomplished by fitting the internal reservoir with a float and a reed switch which senses triggers the tank full signal when the reservoir is filled up to 200 ml or any other set measure. This signal is then used to trigger other solenoids or pumps which stop the main reservoir output and open the drain valve from the secondary reservoir to dispense the liquid into a cup. Using a narrow and long secondary reservoir ensures that errors in measurement do not exceed 5 ml.