Solutions for LPG tank monitoring

So, just switched from hot water tank to GAS heating using LPG bottles, and am now looking for a reliable solution for measuring the bottle levels.

As I understand, the best solution for this will be using “scales” and weighing the bottles? Has anyone done this and are there any other methods to doing this?

I am looking at getting 8 of these 50kg Load Cells,
Load Cell Weighing Sensor | ePartners NZ

Just not sure if this will actually be a reliable solution based on the price of these load cells.

This cannot be attached to the bottle as the bottles are swapped when empty for new bottles.

Look forward to any advice or recommendations.

Thanks

Alternatively, would it be possible to grab an output to get data into an esp from this?

Brand New 150kg Electronic Digital Scales Platform Kitchen Postal Shop Scale | Trade Me Marketplace

I’ve been through the same project and have yet to find a solution that makes life easy.

I use bottles that weigh circa 150kgs and can’t really be lifted into place onto a load cell.

They are also outside in a wet and cold environment.

My generator (viaGenMon) estimates gas usage and I have implemented this in HA, though it’s not very accurate.

I’ve also modified the auto change over valve and added sensors so that I know which bank of bottles are being used.

Here’s my dashboard in HA.

I still have it on my list to add load cells. Probably ‘Z’ type and suspend the bottles on chains.

I’ve explored just about every other option and ruled them out,

Not much help to you, but you’re not alone!

I use Mopeka. Not perfect, but integrates well with HA.

Interesting, i’m thinking my second post would be ideal with the load cell option as everything is there, very minimal DIY required as all the housing etc is there, just see if I can directly tap into the load cells and get some data.

The bottle we get will be measured in KG, and are around 45kg and are swapped when empty.

I will give it a go and update.

Card looks good by the way!

Is that ultrasonic?

Yes, but they have different types depending on the application.

The Mopeka only work on the smaller bottles and I ruled them out anyway due to the batteries and inaccuracy.

The only way to accurately know the contents is by weighing. The levels will change significantly with temperature, making the ‘stick on the bottom or side’ type sensors not suitable for my application.

I know they get used for motorhomes and caravans though.

I wouldn’t consider 120 -2000 gallons small…

I just purchased one of these.

Brand New 150kg Electronic Digital Scales Platform Kitchen Postal Shop Scale | Trade Me Marketplace

Yes, I know they make these too but they’re not designed for the changeable bottles which is my use case.

Do you have an underground or above surface tank?

I’m considering moving to bulk delivery too.

This thread has gotten me motivated with this project again.

I came across this on Alliexpress.

It has dry contact alarm relay output, 4-20ma, 0-10V and 485 bus.

That’s a good deal. How will you integrate it with HA?

Check this out, it’s just all the juice with a load cell, all structure and mounting and all the DIY work in terms of building the structure is done,

Also, the weighing surface is 40x40cm

I will ditch all electronics which is included in the LCD panel on the pole, and use a HX711 to read the load cell and in my case, use a WT-32 ETH01 Ethernet ESP32 and PoE to 5V adapter and run a single ethernet cable.

This could work too,

I guess if you are going to go inline, then you could just use a regular pressure sensor and measure the pressure.

https://www.aliexpress.com/item/1005005510454084.html?spm=a2g0o.productlist.main.19.5b53loLIloLIUf&algo_pvid=8389a1a5-2f1e-4a8b-89f4-3a00b2ea1eb5&algo_exp_id=8389a1a5-2f1e-4a8b-89f4-3a00b2ea1eb5-9&pdp_ext_f={"order"%3A"678"%2C"eval"%3A"1"}&pdp_npi=4%40dis!NZD!34.45!17.22!!!138.69!69.34!%402103247017386664436415971ecded!12000033358648608!sea!NZ!2603925315!X&curPageLogUid=65OnWxiIjnSa&utparam-url=scene%3Asearch|query_from%3A

I bought cheap 4-cell scale and wired the cells to hx711, works well.
But for your case I recommend pressure sensor, much easier, less drift.

How much noise or drift do you get?

No problem with noise and in my case I used it for dosing on screw conveyor so there weren’t permanent load.

Yes, except that the pressure varies with temperature so doesn’t reflect the contents accurately.

I can easily see a 30’ C swing.

Weight is the only accurate measure.

I can’t make out exactly what that is but if it means lifting the bottles onto a platform then it’s not going to work for me.

I’ve considered lifting the bottles with chains with an in-line suspension load cell. Easier to protect from the elements too.