[SOLVED] fuel level measurement method

hai.. i would like to know what are the methods are available at present to measure the fuel level of a car.

For ex: I know floating variable resister type sensor.

Anything else are available. I am interested to know the available methods

Thanks

Two examples, in PDF is for LPG

Thanks tpetar....

Where can i find the details about this sensors functionality and advantages? These sensors are available in market as a individual product or should buy with fuel gauge instruments?

Thing is, if i wanted to design/incorporate a digital fuel gauge in a car, am i need to design specifically for a type of sensor? Or all sensors outputs pins are same so that i can proceed only the top level?

Thanks

karthikkrv85 said:

Where can i find the details about this sensors functionality and advantages? These sensors are available in market as a individual product or should buy with fuel gauge instruments?

Thing is, if i wanted to design/incorporate a digital fuel gauge in a car, am i need to design specifically for a type of sensor? Or all sensors outputs pins are same so that i can proceed only the top level?

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This what I send is DIY variant like example. In market you can buy factory manufactured sensor or complete system for particular car. I send you example for capacitive sensing of fuel as alternative way.

Here is some additional material, maybe useful for you :

Most common sensing is with float arm
A float in the fuel tank rides on the surface of the liquid, like a fishing bobber. An arm attached to the float rises and falls as the float reacts to fuel-level changes. A portion of the float arm moves across a rheostat in the tank sending unit, varying the voltage to the fuel gauge. As the level drops, the float arm reaches points on the rheostat that increase resistance in the circuit. Voltage to the gauge is reduced, resulting in lower readings. When the level increases, circuit resistance decreases and the resulting added voltage moves the gauge needle closer to the full mark.

HowStuffWorks "How Fuel Gauges Work"

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Fuell/liquid level also can be measured with ultrasound, but I dont think so that this is used for car. Gauge for car must be cheap, safest as possible, easy to change, to consupt small amount of current or not at all, easy to build, low cost manufacturing,...

tpetar said:

Fuel/liquid level also can be measured with ultrasound, but I dont think so that this is used for car. Gauge for car must be cheap, safest as possible, easy to change, to consupt small amount of current or not at all, easy to build, low cost manufacturing,...

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Thanks for the details. I read in a article pressure transmitter also used as a liquid level sensor. Do you think this also not used in cars?

karthikkrv85 said:

Thanks for the details. I read pressure transmitter also used as a liquid level sensor. Do you think this also not used in cars?

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No preassure transmiter not use for fuel gauge level, its used to meassure preassure of fuell in fuell installation for injection system. Injection system must have adequate level of preassure to work, about several bars.

If you use LPG/CNG gas then this can be used for measurement, but most common way for LPG is float with arm, and for CNG because very high preassure, preassure type gauge is used (fuel canister is for high preassure like for oxygen/acetillene,... technical gases). LPG 6bar/13bar CNG 150bar/200bar. LPG 60bar max test / CNG 250-300bar max test. On higher preassure like for CNG and technical gases, bottle/canister certainly must not have sharp edges and must be oval with max one opening for gauge and valve.

Thank you so much...

I will query again if i have anymore problem with this implementation. Really thanks for providing the details.

On this diagram you can see part of system between fuel pump and engine, in that part preassure of fuel is meassured and regulated, and fuel pump, pump fuel up to 10bar or over that in some newer car.



No problem, I'm glad to help You!



Additional material :

CNG


LPG

hai can you tell me one more information? in all latest digital fuel gauges, serial output pin(RS232/any comm) will be available?

karthikkrv85 said:

hai can you tell me one more information? in all latest digital fuel gauges, serial output pin(RS232/any comm) will be available?

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No such things in car. Manufacturer of car use CAN bus or other commercial bus systems like 1-Wire for sensors. Manufacturers can have developed its bus systems, not commercial bus system. All diag, setup and tuning goes over diagnostics connector in car such OBDII.

CruzPro FU60 and AEM 30-4100 gauges are providing communication interface (NMEA 0186 or RS232). Please go through the attachment.

karthikkrv85 said:

CruzPro FU60 and AEM 30-4100 gauges are providing communication interface (NMEA 0186 or RS232). Please go through the attachment.

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This is not for fuel level, this uses Lambda sensor to measure mixture ratio oxygen/fuel. You can make with DIY variant everything, you can even put PC in car like MP3 player not problem, then we will get rs232,lpt,usb,lan,wifi,...but .....

First PDf is just counter,reader of some sensor, second explain Lambda values and measurement. No fuel level gauges.

If you need Lambda sensor mixture circuits and other materials say.

sorry for my negligence... I saw the RS232 and hyper terminal details, so i misunderstood...

Thanks for your offer. I am actually new to automotive domain. So any material will be appreciated. I would like to learn in detail..

Lambda sensor measures oxygen, giving voltage on output up to 0,8V. An oxygen sensor, or lambda sensor, is an electronic device that measures the proportion of oxygen (O2) in the gas or liquid being analyzed. There are many different ways of measuring oxygen and these include technologies such as zirconia, electrochemical (also known as Galvanic).




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Oxygen sensor - Wikipedia, the free encyclopedia

Thanks for your relay as well as details...

No prob if there is some other things, just say.