Automatic detergent dispensing system for a warewasher

An apparatus for dispensing detergent into a warewasher which has wash cycle, said apparatus comprising:

• a reservoir for containing the detergent;
• a flow control device which couples the reservoir to the warewasher and controls flow of the detergent into the warewasher;
• and
• a sensor that measures electrical conductivity of water within the warewasher;
• and
• a controller connected to the sensor and operating the flow control device to dispense detergent into the warewasher, the controller has a first mode of operation in which a quantity of detergent dispensed into the warewasher is determined in response to the electrical conductivity of the water, and has a second mode of operation in which a predefined quantity of detergent is dispensed into the warewasher, wherein the controller switches between the first and second modes in response to a determination regarding reliability of electrical conductivity measurements provided by the sensor.

A method of dispensing detergent into a warewasher which has wash cycle, said method comprising:

• storing detergent in a reservoir;
• coupling the reservoir to the warewasher by a flow control device which controls flow of the detergent into the warewasher;
• sensing electrical conductivity of water within the warewasher to produce a conductivity measurement;
• determining reliability of the conductivity measurement;
• when the conductivity measurement is determined to be reliable, dispensing a quantity of detergent into the warewasher wherein the quantity is determined in response to the electrical conductivity of the water;
• and
• when the conductivity measurement is determined to be unreliable, dispensing a predefined quantity of detergent into the warewasher.

An a control system for dispensing detergent into a warewasher which has a reservoir for containing the detergent, said control system comprising:

• a flow control device which couples the reservoir to the warewasher and controls flow of the detergent into the warewasher;
• a sensor which produces a signal indicating an amount of detergent present in water within the warewasher;
• and
• a controller operatively connected to the flow control device and the sensor to control dispensing detergent into the warewasher, wherein the controller has a first mode of operation in which a quantity of detergent dispensed into the warewasher is determined in response to the amount of detergent indicated by the sensor, and has a second mode of operation in which a predefined quantity of detergent is dispensed into the warewasher, the controller switching between the first and second modes in response to a determination regarding reliability of operation of the sensor.