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1/2 npt fuel level gauge
1/2 npt fuel level gauge's composition and working principle:
A bimetal is a piece of metal that is made of two different kinds of metals pressed together. The metal that makes up the sheet metal expands or contracts as it is heated or cooled. Each metal has its own specific expansion rate. The two metals that make up the sheet metal have been specially selected to have different rates of expansion and contraction. When the metal sheet is heated, since one metal expands less than the other, the metal sheet bends, and the outside is the metal with the larger expansion. This bending action is what causes the pointer to turn.
Some newer cars use microprocessors to read the output of the resistors and communicate with the dashboard, eliminating the need to send current directly to the fuel gauge. These systems really help improve the accuracy of the fuel gauge. Let's look at one of these systems. Some newer cars have a microprocessor that takes the reading of the variable resistor in the fuel tank and transmits it to another microprocessor in the dash. Automakers can make slight adjustments to the operation of the fuel gauge, and they can compare the float position to a calibration curve to compensate accordingly based on the shape of the tank. This curve relates the position of the buoy to the amount of fuel remaining in the tank. This makes fuel gauge readings more accurate, especially in cars with complex tank shapes.Systems like these also illuminate the fuel level indicator light to signal when there's not much fuel left. Most of these lights come on when there are a few liters left in the tank, giving you plenty of time to stop and refuel.
The microprocessor also provides some damping for the movement of the pointer. When the car turns or climbs a hill, fuel floods one end of the tank and quickly changes the position of the buoy. If the needle is too responsive to all these changes, it will keep wobbly. The software then averages the last few float position readings. This means that the movement of the pointer position will be slower. When refueling your car, you may have noticed that the needle does not point to the full position until long after you have filled it up.
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