Water Tank Level on Colour C-Touch

Hi Everybody,

I have a project currently in the making and the client would like to be able to display his water tank levels, 4 of them, on his colour touch screen.

I found the WIKA probe on the Clever Home website, thanks Brendan, this probe appears to have a 4-20mA output. I assume I can feed this into a C-Bus General Input Module, map it to a group address and display that GA on the C-Touch.

Is it that simple, I'm yet to buy the parts, or is there something else I need in this situation.

Anyone that has made this work on a Colour Screen I would be keen to hear your success story, or if anyone has another way to approach this, it would be much appreciated.

The Rake.

 

It should be that simple. You can use a bar graph component on colour C-Touch to show the water level going up and down.

 

I wish it was that simple to get a minder 4-20ma input on the touch screen !

 

Not sure if this is of any help to you, but the Australian electronics magazine "Silicon Chip" published a wireless water tank monitoring circuit a few months ago.

I'm relatively sure it could be modified to suit your purposes if you're interested.

If so, let me know, and I'll dig up the details, and post them back here.

Darpa

 

I cannot remember the brand but I bought a 4-20Ma pressure transducer just attached to the bottom of the tank. cost around $200 once callibrated (need to know the values for full and empty) it gives level to 0.1%

Charles

 

That is effectively what the WIKA probe is doing, but yes any pressure transmitter can be used if you have access to the bottom of the tank.

What the WIKA probe allows is for those that have say underground tank to use a simple pressure transmitter and drop it in from the top into the water to measure level.

As long as you know how to convert the pressure into a height and/or percentage it is very easy.

If you dont have the pressure Tx at the very bottom then you need to have an offset as well to get a real level (it obviously cant measure below itself)

Mick

 

Thanks for the input everyone, I have the cables in place for a wired solution, thanks for the offer Darpa.

The tanks are all inground concrete. Not having done this before, reading the wiring diagram it appears that it's a 2 wire probe power it and the General Input module will read the output, right???

Calibration is something I had missed, can anyone shed any light on how you calibrate these sensors. Is it empty the tank, get a reading then fill it and do the same?? Currently 3 of the tanks have water in them the 4th is to be a grey water tank, empty at the moment.

Thanks again for the input all.

 

A two wire device will regulate the current in the circuit (4-20mA), where in your case 4mA will be 0 and 20mA will be a full tank. The GI will accept the current input and then do whatever it needs to do with it (probably read a voltage across a resistor).

You still need to power the transmitter - the GI will not do that itself. Power is on the same wires as the signal (2 wire device as opposed to a 4 wire device where power is on separate wires)

Most likely you will need a 24VDC supply for the transmitter and you connect the + of the supply to the + of the Tx, the - of the Tx goes to the + of the GI and the - of the GI goes to the - of the power supply.

Calibrate was probably the wrong word (calibration is done by the supplier and can be done by you to ensure the reading are always accurate within a specified range), you need to range it so that you get something that is suitable for the pressure range you need to measure.

You don't want to see that you have 12mA of water in your tank, nor do you want to see that you have 100kPa of water. You need to convert the mA into the units you want to see either meters, millimetres or percentage.

P = rho x g x h

so when you know the pressure, the liquid, then you know the height of the water above the sensor. Then add the offset (distance from the bottom if any).

You need to know the range of the Tx as well and you also want to ensure that it is close to the range you are measuring other wise you will loose accuracy and never get a full range signal (20mA).

eg, if your tank is 2m deep, then you want a pressure range of 0-20kPa (P=1x10x2) or close to it, but never under it.

Mick

 

Water Tank Level

Just spoke to Wika and their LS-10 probe is ~$800 + ~10m cable (I need about 30m). Does anyone know of a more reasonably priced reliable sensor that would work for a 15kl above ground tank and for a 100Kl concrete underground tank (approx depth of tank 2.5m)?

Thanks.

 

Ive got this same issue im looking for a pressure transducer to put in my water tank that is 2.2m high which is 0-22kpa or 0-3 psi and to give me a 4-20mA signal but the prices for these are rediculas at about $4-500, if you or anyone can find a reasonable priced pressure Transducer for this application it would be much appreciated if you could point me towards them.
Thanks
Chris

 

In my previous post where I mentioned the water tank level meter from Silicon Chip Magazine (Australia), the entire cost of that kit was well below the prices you guys are talking about ($99.95), let alone the cost of just the sensor.

I cant remember exactly what sensor was used, but if you have a look at the silicon chip website (http://www.siliconchip.com.au/), and do a search for an article on "Water Tank Level Meter", you should find the article talking about what sensor was used, as well as the specifics of what it's capable of, as well as a guide on the best way to install it.

Note though, that they do ask you to pay $7.95 for access to the full articles, but considering the $$ it looks like it could save you, thats not exactly much of an issue.

Also, I am not in any way affiliated with Silicon Chip Magazine, I'm just a reader of their publication.

Darpa

 

Had a look on the site but couldnt find anything regarding pressure tranducers or similar its just there own kits that only talk to each other, all i want is just the pressure tranducer by itself..................cant find one anywhere????

 

What I was meaning was that there is a kit that they have developed, and one of the components of that kit is a pressure transducer, as you wanted.
I am in Sydney at the moment and wont be going home until late december, otherwise I'd look up the exact sensor used in my copy of the magazine.

My intention was that you have a look at the article on their website, and find what sensor they used in their kit so that you can try to source one elsewhere.

Silicon Chip do not sell any components, or even kits, they are simply a magazine that publishes circuit designs.

Darpa

 

Hi Guys

I intend to eventually install a Maxbotix (Ultra sonic) sensor in my Water tank (6000L) and monitor it using xPL ....One of the xPL developers has designed a little board which you can connect 4 Maxbotic sensors directly to.....Have a look here...
http://www.rgbled.org/maxbotix/index.html

I have also designed a little board which will monitor 4 levels and have installed into my water tank..have a look here....

http://s195.photobucket.com/albums/z38/frankmc_2007/

HTH
Frank

 

Here's another possibility.

http://www.anadexlabs.com.au/shop/catalog/Aquameta-420-5-4-20mA-level-probe-p-16220.html

and interface to C-Bus

http://www.anadexlabs.com.au/CbusAn420.htm

 

I cound not find the website I bought my tank pressure transducer from but today I found the data sheet and now found the website

http://davidsonemail.com/products/pressure/druck/sensors/process/ptx-1400.asp


you simply mount at the bottom of the tank and gives you a 4-20ma indication of the height

I have one in my tank for 4 years and had no issues

Charles

 

Thanks for that charles ill give them a call tomorrow any idea what you payed for it?

 

I purchased one suitable for tanks to 4m for $375.10 including GST from Anadex Labs.
They also had a good link http://www.anadexlabs.com.au/CbusAn420.htm that shows how to integrate into C-Bus.
http://www.anadexlabs.com.au/shop/catalog/Water-depth-probes-orderby0-p-1-c-272.html

Bill