Ultrasonic water level sensor ?

[TheBig1]

a length of pipe to contain a small plastic (water tight) container with a magnet in, allowing it to move up and down the pipe. Fix that to one wall inside the tank, with the pipe open to water entering in the bottom of the pipe. Then a series of magnetic reed switches up the outside of the tank. It would be massively better than the brass contact pins in most tanks. The reed switches could be used to switch LEDs to show the true level of the water. Or use them with a few basic components to power a display gauge

 

[berni109]

How about one of these
https://rover.ebay.com/rover/1/710-...0001&campid=5338547443&icep_item=402379833292

 

[Chuns]

Oh, s**t, sorry all, in my eagerness to help I got two recently fitted products mixed up. Is not the Mopeka, that is on by gas bottle, the water tank gauge was from Votronic, and is not ultrasonic, it has a probe that is inserted through the top of the tank.

Not much help at all.

Couldn't easily find an emoticon for ‘hangs head in shame'.

 

[Gromett]

I was more thinking of shooting through the side of the tank as I canna get inside it anyway!

Ah, that is an interesting idea. Not sure how that would work in practice as I have never looked into that. I ended up looking into pressure sensors which connect to the outlet at the bottom of the tank. The higher the pressure the more water in the tank. Would need to be calibrated to each tank though. This was to be an arduino project I was messing around with.

 

[PeteH]

The ones on my old(er) R-V consisted of a series of "buttons" inserted at 4 levels in the side of the tank. I assume they worked on a capacitive principle?. They where fairly accurate, on the Fresh tank at least, the ones on the grey and black less so. I think the similar devices on cassette toilets for showing the warning of "full", are only magnetic float switches?.

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[EdwardFT]

What does the fuels tank gauge use? Whatever it is, that seems to work.

 

[Gromett]

a length of pipe to contain a small plastic (water tight) container with a magnet in, allowing it to move up and down the pipe. Fix that to one wall inside the tank, with the pipe open to water entering in the bottom of the pipe. Then a series of magnetic reed switches up the outside of the tank. It would be massively better than the brass contact pins in most tanks. The reed switches could be used to switch LEDs to show the true level of the water. Or use them with a few basic components to power a display gauge

I saw a similar but more basic version on a self build. He put two elbow joints on the tank, one at the top and one at the bottom and connected them with some clear pipe. Inside the pipe was a small plastic ball that rose and fell with the level in the tank.

 

[PeteH]

I saw a similar but more basic version on a self build. He put two elbow joints on the tank, one at the top and one at the bottom and connected them with some clear pipe. Inside the pipe was a small plastic ball that rose and fell with the level in the tank.

That has been used to indicate fluid levels before, a small magnet in the float triggers remote indicators?. Basic "stop/go" lights. Marine practice used them as far back as the 60`s as an alternative to a series of float switches in chambers. The low level one was often connected to an audible warning too. very analogue with multi-stranded cable connections

 

[EdwardFT]

What does the fuels tank gauge use? Whatever it is, that seems to work.

I speak quite good English, my autocorrect doesn't.

 

[PeteH]

I speak quite good English, my autocorrect doesn't.

I`m glad I`m not the only one to have issues with "spellchuckers". especially if trying to do a quick reply on the i-pad!. You get some very weird outcomes.

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[Two on Tour]

Edit :

 

[Jaws]

What does the fuels tank gauge use? Whatever it is, that seems to work.

Just a float on an arm which is hinged from the top and activates a wiper on some resistive wire.
The signal is simply damped be a capacitor ( to stop wild swings )

 

[Treeeev]

Hi John

What about something like this ? Stuck on the outside of the tank at the required levels. I'm sure AllanK used these on his water tank in his minibus conversion to camper

Cheers

Trevor

 

[Don Campbell]

Would love to know also.. we have a massive 180 litre water tank and our gauge is divided into quarters, which means when its a quarter full its somewhere between. 44 litres and zero!

Did you get that wrong? If it reads in quarters and full is touching the 180L sensor, then 75% means anywhere between 135 and below 180, 50% means anywhere between 90 and about 134 and 25% means anywhere from 45 to just below 90. Once the water drops below 25% it would show no reading or empty. That's assuming the sensors come down from the top if they are rods or are stuck on the side of the tank either of which I think is the norm. Maths puzzle for today!!

 

[Jaws]

Hi John

What about something like this ? Stuck on the outside of the tank at the required levels. I'm sure AllanK used these on his water tank in his minibus conversion to camper

Cheers

Trevor

Bloody brilliant !!! That is spot on.. One on order.. If it works out I will let you know
Thank you !

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[gpat]

We use ultrasonic level monitors all the time in the Water Industry. They have been around for years. However they are not always simple nor reliable. A decent unit will set you back around £800 not including fitting. They require calibration and sometimes the set up can be difficult. I think they are a bit over the top for a little water tank.

Only thing I can think of would be an oil tank Ultrasonic sensor. These are cheaper as they are widely used

Watchman Sonic Oil Level Monitor / Gauge | Watchman Oil Monitor

Market leading Watchman Sonic Oil Level Monitor. Quick and easy install, suitable for steel or plastic tanks, low power consumption.

heatingpartswarehouse.co.uk

The ones we use also use power and emit a regular and annoying clicking

 

[Diabalo]

Hi John

What about something like this ? Stuck on the outside of the tank at the required levels. I'm sure AllanK used these on his water tank in his minibus conversion to camper

Cheers

Trevor

I think that item will only indicate a set level not a full range, could be wrong let's see what John makes of it

 

[Treeeev]

I think that item will only indicate a set level not a full range, could be wrong let's see what John makes of it

Agreed, but with more than one on the tank, they could be used to indicate the different levels

Cheers

Trevor

 

[Neil n Pat]

Going analogue here.... back to basics for such a simple requirement knowing what your water level is. Our current water level indicator is a bank of LED's in the panel which have a mind of their own.

Stainless Steel Boat Water Level Gauge Car Water Tank Level Gauge Indicator 190ohm for Auto Truck Marine Car Meter - AliExpress 34

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Page Not Found - Aliexpress.com

 

[Richard n Ann]

Bloody brilliant !!! That is spot on.. One on order.. If it works out I will let you know
Thank you !

How will you use the output? 0.5v is hardly enough to switch a transistor on properly.
Also there's working voltage and outside working voltage. Hope it comes with a diagram

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[Jaws]

How will you use the output? 0.5v is hardly enough to switch a transistor on properly.
Also there's working voltage and outside working voltage. Hope it comes with a diagram

Well it is easy enough to use put the output though a 2 stage voltage amp.. even easier to stick it it on to an old analogue meter from a cb radio !

 

[Jaws]

I think that item will only indicate a set level not a full range, could be wrong let's see what John makes of it

I agree but I only need one level indicated.. when the tank gets down to 1/4 full it is time to fill up

 

[Diabalo]

I agree but I only need one level indicated.. when the tank gets down to 1/4 full it is time to fill up

Oh I see, I thought you was talking about the grey tank, I never have a prob with the fresh tank just the grey.

 

[Richard n Ann]

I've ordered a float switch, works with a Reed switch in it, seen them used on fridge condensate trays to bring a heater on. (It's on another thread somewhere )
Going to fit it a quarter of the way up for a 25% warning LED

https://rover.ebay.com/rover/1/710-...0001&campid=5338547443&icep_item=133521514992

 

[tonyidle]

I am sure there is a good reason not to use it but years ago my cars used to have a floating ball-cock device in the petrol tank. When moving it was all over the place but when parked it was fairly accurate at measuring how much fuel was in the tank.

They're used in vehicle fuel tanks to this day. They are cheap & easy to deploy because they're immersed in petrol or Diesel which doesn't affect their electronics.

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[tonyidle]

How about one of these
https://rover.ebay.com/rover/1/710-...0001&campid=5338547443&icep_item=402379833292

That looks like the complete answer - cheap too .

 

[Two on Tour]

That looks like the complete answer - cheap too .

Providing you have the free height above the tank required to mount the unit.

 

[tonyidle]

Providing you have the free height above the tank required to mount the unit.

Very true. Although at the price I wouldn't be afraid of a little butchery to separate the battery pack & aerial from the sensor. If it does what it says it's an easier & more accurate option than most .

 

[Two on Tour]

Although at the price I wouldn't be afraid of a little butchery to separate the battery pack & aerial from the sensor.

A man after my own heart.

 

[Jaws]

A float type sender unit is about the best way to go, but sadly, being an old fart, I struggle with some jobs nowadays.. And pulling the tank out from the Autotrail would be very difficult for me, hence looking for alternatives

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