Oil Level Hydraulic Tank need Some Advice..

Projects General Guidance
1

Hey guys!
Thanks for coming to this topic, im new using arduino and i need some advice for my project on my campus.

the project itself is to make real time monitoring for oil level on hyraulic tank so we can know if the oil is leak out of the tank when its on operation. so its gonna work like this

-Lcd will show the amount of oil it will be placed on opertaor cabin(low or high, i will try to show the amount of oil by liter later but i will go with low or high first. )

  • the sensor send signal to arduino

i see lot of water level sensor been widely used with arduino... so me and friend want to try to make Oil level hydraulic monitor For excavator or maybe truck (hydraulic tank for its dumping) so here my thought of what i will gonna do with my project:

  1. first i will try use sensor with some cable based(?) like Simple Water Level Indicator Alarm Circuit Diagram but i heard this one not really good with conductivity on oil.

  2. I will try with hcsr04 sensor that will work with any fluid, my biggest concern for this one is it gonna work on pressurized tank? or only vented one?

  3. or i will try with laser sensor like ToF range sensor?

With the three sensor i mention above will it be work on with condition at 140°F of heat or below?
and i will try to place the sensor on filler cap.

PS: im really sorry for the bad english, and i will try to update this topic along with the project progress.
i include some example of the tank on attachment

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2

I'd start by Googling "oil level gauge electronic" and look at the images

https://www.google.ch/search?q=oil+tank+gauge+electronic&source=lnms&tbm=isch&sa=X

3

By far the best and very reliable method is to use the ultrasonic sensor and it is simple to install and calibrate.

  • Conductivity probes don't work with oil. Even with water you need to use AC for sensing or else the probes will get deposits by electrolysis.
  • Ultrasonic. Yes you can use the cheap HCSR04 modules.
  • The best use a professional US sensor from a comapny called Maxbotix HERE

Maybe a bit pricey from a DIY angle but the results are very reliable. I am using it for the last few years and no issues.

4

By far the best and very reliable method is to use the ultrasonic sensor and it is simple to install and calibrate.

  • Conductivity probes don't work with oil. Even with water you need to use AC for sensing or else the probes will get deposits by electrolysis.
  • Ultrasonic. Yes you can use the cheap HCSR04 modules.
  • The best use a professional US sensor from a comapny called Maxbotix HERE

Maybe a bit pricey from a DIY angle but the results are very reliable. I am using it for the last few years and no issues.

5

On a machine, the oil tank might be a foot high, and 2 feet long.
Although I usually recommend the ultrasonic, the waterproof unit requires about 9.5 inches of free air above the highest level or it will output false readings.

If you use a sight gauge and a series of beam break sensors, you could get some feedback.

If the tank is not level, then it is really hard to measure oil height.

This is a case where you absolutely must define your project before selecting a sensor.

the ultra sonic operates by sending a ping.
think rifle shot.
at the source, the noise is deafening.
after some time, the ringing in your ears reduces and you can hear the sound of the target.
the sound pressure that reached the target for the bullet is a small piece of lead that does not alter shape but the ultrasonic wave is broadcast and disperses. the reflected wave can only reflect the small bit that reached the target.
the reflected wave is also broadcast so that the energy of the return is very small.
in an enclosure like a steel tank, the rest of the original signal is still echoing around, the reflected energy is still echoing around and the sensor has to pick out the signal from the noise.
the good thing is that the first signal to return is the reflected signal from the target. all the echo come after.

the cheap sensors have a harder time getting the correct signal. the maxbiotics (I am told, but never used) have less of this problem because of better design and construction.

oil tank level by fluid column weight (pressure at the bottom of the tank) cannot be easily done in a pressurized tank.

you can get sensors that will read oil height but sight, not electrical resistance
look at the sight in a car battery. a plastic rod with a beveled end. UN-submerged, the end reflects the light, submerged, it reflects it differently. you can detect the difference from outside of the tank.

weight of tank is not workable on vibrating machinery.

bottom line, define the problem really well.
machine not running sitting on a level surface is easy.
a bulldozer on a hill is not so easy.

6

In your search for a proper sensor, remember the oil may get hot enough to boil water!

Paul