| 摘要 |
Apparatus for measuring the amount of fuel in a tank comprises a capacitive probe whose capacitance is a function of the fuel level in the tank, an electronic circuit including a monostable multivibrator to which the probe is connected as a timing capacitor and a trigger source for repetitively triggering the monostable multivibrator to provide a series of output signals whose duty cycle is a function of probe capacitance, and a display responsive to the pulses or a signal derived from them to indicate the amount of fuel in the tank. To make the monostable output signal duty cycle directly proportional to the amount of fuel rather than to the fuel level, when the capacitance profile is not matched to the tank, the monostable duty cycle is modified before display, by transform unit (19) which provides, first, a conversion of the output signal of the multivibrator proportional to the fuel level into numerical value (20), after, a modification of said numerical value into numerical value proportional to the amount of the fuel using a look-up table stored in a read only memory (ROM) (21) and, finally, a conversion of this last-mentioned numerical value into output signal duty cycle proportional to the fuel amount in the tank (22).
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