Abstract: A fuel tank probe includes a water level float and a fuel level float. A fuel weight sensor is incorporated into the fuel tank probe to report the density of the fuel within the tank. The fuel weight sensor includes a compressible bladder whose shape changes as a function of the density of the fuel. A magnet on the compressible bladder moves in conjunction with the changing shape of the compressible bladder, and allows a fuel column height to be measured. The density of the fuel can be determined from the measured fuel column height.

Abstract: A system and method for calculating the flow rate of a dispensing point or flow capacity of a pump and fuel delivery system and determining if the dispensing point or fuel delivery system has a blockage and/or a performance problem if the calculated dispensing point flow rate is other than expected. The calculated dispensing flow rate is calculated by collecting fuel tank level data points for a dispensing point that fall within start and stop events of the dispensing event. The slope of a fitted line to the fuel tank level data points is used as the indication of the flow rate of the dispensing point. Different mathematical techniques may be used to improve the flow rate calculation to compensate for the minimum resolution of collecting fuel tank level data and the dead time included in the data of a dispensing transaction.

Abstract: Determining a maximum dispensing efficiency of a dispensing point in a fuel dispenser and determining if a dispensing point has a blockage and/or a performance problem if the maximum dispensing efficiency is less than expected. The maximum dispensing efficiency is calculated by determining the dispensing events exhibiting the lowest time for dispensed volume from a set of volume and time pair measurements for the dispensing point. The dispensing events exhibiting the lowest time for dispensed volume that are used to determine the maximum dispensing efficiency are taken from dispensing events where the amount of dead time, the time between the activation of a fuel dispensing event and the engaging of a nozzle and the time between the disengaging of the nozzle and the deactivation of the dispensing event, and customer or pre-pay transaction controlled reduced flow rates are minimized.

Abstract: A method for storing a k-bit output value for each of a plurality of m-bit input values in a memory having an n-bit word stored at each of 2.sup.n n-bit addresses, wherein m, n and k are positive integers, m>n>k and m-n.gtoreq.k, the method comprising the steps of storing a first k-bit output value corresponding to a first m-bit input value at a first n-bit address in the memory, and storing the 2n-m most significant bits of the first n-bit address at a second n-bit address, the stored 2n-m most significant bits of the first n-bit address occupying the 2n-m most significant bits at the second n-bit address, the first and second n-bit addresses being selected such that the n most significant bits of the first m-bit input value correspond to the n bits making up the second n-bit address and the m-n least significant bits of the first m-bit input value correspond to the m-n least significant bits making up the first n-bit address.

Abstract: An electro-optical mouse has a four-quadrant photodetector, each quadrant producing a voltage proportional to the amount of light impinging thereon. The mouse slides over a surface having optically contrasting, i.e. reflecting and nonreflecting, indicia thereon. The position of the mouse relative to a coordinate system in the plane of the surface is determined by projecting light onto the surface and then detecting the amount of light reflected from the surface onto the respective quadrants. The mouse is able to detect within which of four ranges the amount of light impinging on each quadrant lies. A two-bit code indicating the range is generated for each quadrant, thereby forming an eight-bit detector code. In the case where the eight-bit detector code is the same, i.e.

Abstract: A conventional three-electrode wedge-and-strip pattern in a digitizer tablet surface is used with a conventional cursor or stylus. A phantom cursor electrode is located at predetermined coordinates of the active area of the digitizer tablet beneath the X, Y and balance (B) electrodes and separated therefrom by a layer of dielectric material, preferably an air gap. Prior to use of the digitizer apparatus, the phantom cursor electrode is electrostatically coupled to the X, Y and B electrodes in order to obtain data signals representing the phantom cursor's measured coordinates without compensation for resolution distortion. A microprocessor produces a correction factor using the data signals and the predefined coordinates of the phantom cursor electrode, which correction factor is applied in normal use to compensate for resolution distortion resulting from the unavoidable gaps between the X, Y and B electrodes.

Abstract: A method and apparatus for calibrating an electro-optical mouse during the detection of light reflected from a surface with optically contrasting indicia. The voltage output from the light detector is compared with stepped ramped sequences of reference voltage signals representing a count, the ramped sequence being stopped in response to each transition of the comparator between a first state where the amplitude of one of the input signals is less than that of the other and a second state where the amplitude of the one of the input signals is equal to or greater than the other. A processor determines the highest and lowest numbers at which any of the ramped sequences are stopped; and calculates at least one threshold value in dependence on the difference between the highest and lowest numbers.

Abstract: A charge ratio tablet having three patterned electrodes for determining the position coordinates of a stylus relative to a first area on the tablet is provided with a menu in a second area. The menu includes first and second pluralities of menu electrodes, the three menu electrodes of the first pluralilty having a first geometric pattern and the three menu electrodes of the second pluralilty having a second geometric pattern. The patterned electrodes and menu electrodes are driven in accordance with a predetermined sequence. The processing circuitry determines the position coordinates of the stylus if the signal induced in the stylus in response to driving of the three patterned electrodes simultaneously has at least a predetermined magnitude. The processing circuitry carries out operations other than position coordinate determination if instead the stylus is capacitively coupled to a driven menu electrode. The processing circuitry discriminates which menu electrode is capacitively coupled to the stylus.