| 摘要 |
Apparatus for dispensing a preset monetary amount of product, such as fuel, sold by volume and for use with a dispenser which calculates and displays a continuously increasing cost of the delivery has a number of selector buttons which relate to units of cost and which when selected set an appropriate number into a counter. The counter is coupled to the display, and the count is decremented by one for each unit cost of product actually delivered. During delivery of the first unit a store calculates the difference between a unit cost and the cost of a small predetermined volume, which volume is required to be delivered slowly to end the delivery and avoid under- or over-delivery due to mechanical or fluid inertia of the dispenser. When the counter indicates the final unit preselected is being delivered, a comparator compares continuously the cost displayed for that unit and the stored difference and when they are equal the delivery rate is slowed for the final predetermined volume. The apparatus may be used with pre-stored values where delivery is by volume rather than cost.
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