help on fuel level measurment

[milindmiet]

low pass fuel level

i m measuring fuel level of car there is a floater in the tank which gives analog voltage and i measure it through pic ADC and display the result but whwn car moves floatre output varries too much which shows intemittancy in display is there any specific or any good method to remove this sloshing problem

 

[ndru_w]

fuel level sensor unstable

Hi
It's a normal thing that liquid fuel is moving in a fuel tank when you're moving on a rough surface. The easiest way to avoid this problem is to measure e.g. 10 times the analog value and then calculate the average.

 

[FvM]

easy way to measure fuel level cars

That's why oldtimer cars have a bimetal driven tank level indicator and today's an electronic filter.

 

[davemaster]

fuel tank measurment

i m measuring fuel level of car there is a floater in the tank which gives analog voltage and i measure it through pic ADC and display the result but whwn car moves floatre output varries too much which shows intemittancy in display is there any specific or any good method to remove this sloshing problem

Greetings,

How about work with an ultrasonic level meter? Ill search some available on google. Unfortunately, each car/bus/truck/vehicle has a different model of tank, therefore a different way to install an ultrasonic level meter.

Let me know some ideas to keep this going.

 

[bobcat1]

Hi

Use pressure senesor to measure liquid level - serach freescale site for pressure sensor app-note to learn more

You can also get pressure sensor from mouser electronics

All the best

Bobi

 

[mrcube_ns]

Only good solution is to make digital low pass filter (with very very low frequency, or in term of period in tenth's of second).

Real amount of fuel is changing very slow in metter of time while you drive car, so you can make filter where changes in level can be very slow.

E.g. if you make step up level change, your filtered level can rise up 30 or even 60 seconds. By this you'll eliminate changes while you driving car (this changes will be too fast for your filter, so your filter will always give average level).

Regards,


Mr.Cube

 

[Kripton2035]

i m measuring fuel level of car there is a floater in the tank which gives analog voltage and i measure it through pic ADC and display the result but whwn car moves floatre output varries too much which shows intemittancy in display is there any specific or any good method to remove this sloshing problem

Greetings,

How about work with an ultrasonic level meter? Ill search some available on google. Unfortunately, each car/bus/truck/vehicle has a different model of tank, therefore a different way to install an ultrasonic level meter.

Let me know some ideas to keep this going.

sorry but it is FORBIDDEN to use ultrasonics in a fuel tank... too dangerous it could burn. pressures sensors are allowed I think as there is no electricity and no waves in the tank.

 

[FvM]

Ultrasonic sensors, that confirm with intrinsic safety requirements are used in industrial measurement applications, so I see no reason, why an appropriate designed ultrasonic level sensor shouldn't be possible. But I think, it would have basically the same problems with unstable level while the vehicle moves. Although different sensor principles have been evaluated through the years, most cars still use moving floaters as fuel gauge.

 

[Kripton2035]

are your industrials application measuring fuel levels ??? inflamables liquids levels ??? I'm not sure ...

and you're right the car are moving, which makes the measure more dangerous with electrical components..

 

[FvM]

Intrinsic safe electrical instrumentation can be used in any ignitable atmosphere. The basic concept is to keep the dissipated energy below the ignition energy, also in the case of any possible fault. If an utrasonic transducer is mounted in the explosion hazardous zone, voltage and stored energy of the connected circuit must be limited accordingly, but a level measurement should be still possible. Mounting the transducer at the tank outside and measuring through the wall may ease explosion protection.

 

[davemaster]

i m measuring fuel level of car there is a floater in the tank which gives analog voltage and i measure it through pic ADC and display the result but whwn car moves floatre output varries too much which shows intemittancy in display is there any specific or any good method to remove this sloshing problem

Greetings,

Can you post your circuitry? It helps us a lot for answer your question.

Best Regards

 

[hameeds01]

the simplest way is to use a low value capacitor in parallel across the Analog o/p along with a diode in series if required

 

[rongo024]

Did you set the floater by own or use the floater supplied by the car company?
If you use the supplied floater, then please inform me the the interfacing procedure. It means the the description of the wire.