Measuring fuel level

[makki]

Hmm, sounds not that good (for my personal relief: I really said "better to wait" )
Will try to verify that but with the single-transducer SRF02 (which should be worse - initally I looked for something with <15cm) this looked much better&accurate so far.
I'll put this thingy into the "salt-bin" soon and see what happens..

Makki

[Warichet]

Hmm, sounds not that good

Maybe, maybe not.
Don't forget, the comments above are from my personal point of view, with a "kind of rectangular" tank, where the max width is around 72cm. Hence the risk of having the beam touch the sides is real in my case.

If you have a rather "fat" tank, or the opening is right in the middle, you might not be affected by the above limitations.

Another problem I just discovered: the tank has "profiles" inside, to strengthen the structures (plastic), so the risk of reflections is even higher

Also, the sensor is labelled "range finder" not measuring device, we are not allowed to complain

I'll put this thingy into the "salt-bin" soon and see what happens..

You still have room in there ?

[anlo007]

Hallo,

I use the Prignitz-Sonde for my oil-tank and it works very well.
In earlier times, we used the Siemens Ultrasonic units for our storage tanks, but wih a round tank, with round ends, it is complicated to calculate the content from the level-hight.

Today we put the tanks on scale-elements (of course not possible for earth-tanks). 2 or 4 will do and we get the exact amount. If this is an alternative, I can give you the adress of a new-sealand supplier for these elements.

[Warichet]

Hi,

I use the Prignitz-Sonde for my oil-tank and it works very well.

I considered this alternative for a while (I use a Prignitz in my water pit) but they are not ATEX certified.

Today we put the tanks on scale-elements

I also thought about this for a while, but the tank has to be empty to insert the gauges. Even 100L (almost empty is too much to move)

and we get the exact amount.

Yes, indeed, as the weight is independent of the shape of the tank. And it only needs a simple conversion from Kg to Liters

I can give you the adress of a new-sealand supplier for these elements.

Yes, please. I don't know where I'll end-up with my current tests. (maybe everything in the trashcan)

[anlo007]

Hallo,
sorry for the delay.

1. Prignitz-Sonde :
I asked them, if i can use it for my heating-oil tank and they agreed. You can not use it for (car) petrol.

The Prignitz-SOnde is always below the liquid level and therefore you need no ATEX-Certification as far as I know.

2. The scale elements, you can place underneath 2 or 4 stands of your tank. (if 2 make some Blocks under the other side to level the system out).
Normally it is quiet easy to lift the stands of the tank with a hydraulic car jack.

here the adress: shibu.joseph@ptglobal.com
They also have a REG unit which gives you the weight direct as a analog output.
0-20mA, 4-20mA, 0-10V. It is called PT100 LC

This solution is of course more expansive, but certainly the most accurate.

For my private home I use the Prignitz-Sonde.

[Warichet]

sorry for the delay.

No problem, thank you for the time & trouble to help me

The Prignitz-SOnde is always below the liquid level and therefore you need no ATEX-Certification as far as I know.

ûh ?!? I'm not sure. I'll re-read the ATEX specs.

The scale elements, you can place underneath 2 or 4 stands of your tank. (if 2 make some Blocks under the other side to level the system out).

OK, fine.

This solution is of course more expansive, but certainly the most accurate.

Indeed, it is totally independent of the shape of the tank. No crummy calculations needed
I wonder how to combine 2 (or 4) weight sensor, into a single reading, I guess I'll get more info from your contact.

Thanks again.

[anlo007]

I wonder how to combine 2 (or 4) weight sensor, into a single reading, I guess I'll get more info from your contact.

This is the normal bridging of the scale-elements. You only habe to take the result x2 to get the full weight.

[Warichet]

sounds not that good

I've put the "thing" into production.
First measure, totally wrong, the lobe angle is way too open, the beam reaches the sides of the tank at 1m
I tried the velvet around the sensor, it's worse
I put the "thing" back in place, ôh miracle, a meaningfull reading.
So, I guess that just by accident, I've oriented the 2 sensors in the right way (you don't need to be nice, to be lucky )

The sensor is 1,72m from the tank bottom (measured inside, bêrk)
The fuel level is at 0,60cm
The sensor says 1,12m

I'll put this thingy into the "salt-bin"

You might re-open the "salt-bin", before the sensor are corroded by the salt

[Warichet]

Bad news
Checking again this morning ...
The fuel level increased from 0,60 to 0,68m
Either someone filled my tank at night or the sensor is inappropriate for the application at hand.

Not forgetting that 0,60m is still far from the bottom and reaching the area where I'm interested in.

Test failed .
I think the "thing" will fly.

[TRex]

@warichet, from 0,6 to 0,68 ist means, that the pressre growth up 0.08 bar (80 Milibar)

I think, this is the normal area of athmospheric air pressure variation.

Remember, your Sonde needs an an external connection to the "air pressure", to avoid the athmosperic variation.

i Think, your air pressure in pyrenees is now lower as yesterday, yo have bad weather....

[Warichet]

Hi Peter,

Thank you for the input

from 0,6 to 0,68 ist means, that the pressre growth up 0.08 bar (80 Milibar)

Mmm, didn't think about that, but in this particular instance, the sensor is an ultra-sonic device (not like the Prignitz, which indeed works relative to atmospheric pressure).
So, I don't think it is influenced by air pressure, maybe someone can confirm ?

Anyone having a pointer to a price attractive ultra-sonic sensor ? Those I've found are from the industry and are in the 350-500€ price range.

Also, I've checked the weight sensor alternative. This seems not feasible in my case, tha tank is all plastic, no legs (the bottom is flat on the ground) to put a weight sensor underneath.

you have bad weather....

Yes, indeed, we have had 3 days rain in 3 months

[anlo007]

Use the Prignitz, it is the cheapest solution.

[vento66]

I think its to Late

[makki]

I think its to Late

No, just 10-20 EUR were wasted and here (for really very different things) it works perfectly fine so far -although I'm not finished testing an won't post any recommendations until then..
I've got the Prignitz myself in the Zisterne (too lazy to ask leo to translate) and now, currently it's broken and reports 0,5m too much (which i compensate by SW right now, because the error is linear - no big issue and I'm sure it'd be fixed if I send it in, but still this needs some "Action")

@Vento: I thought your the the one to prefer US I have to admit the pressure sensor lost in a 1 month insight so far (although the Prignitz was running 2Y and the US was ony looked at for 2 days!)

Makki

[Warichet]

No, just 10-20 EUR were wasted

I persist to think that the experience was worth the tests.
I guess I would have read totally different comments if the test had been successfull .
Also, the sensor is not appropriate for a "narrow" tank (70cm), but I'm pretty sure it works file for a "fat" tank, I mean the round model or the "pear" model, where there is enough distance between the sensor beam and the sides of the tank.

I've got the Prignitz myself in the Zisterne and now, currently it's broken and reports 0,5m too much

?!? it's broken ?!?
Mine is broken as well !!!
It has worked fine for over a year, now the reading changes all by itself, even when the sensor is not in the water pit
So, I'm a bit reluctant to buy yet another PT-LM

I've still investigated about other ultra-sonic sensor, but they are all for the industrial world and costs range from 350€ up to 500€