Liquid level measurement.

[Joe McGivern]

I want to measure liquid level , the distances being between zero and six metres in depth.

I know there are sophisticated ultrasonic instruments on the market and they are relatively expensive. Laser measurement seems to be another option but I have not any experience of these.



I want to explore the possibilities of constructing an unit that will measure distance as in paragraph one and will give out the measurement in the form of a voltage or current signal which can be used to indicate in
Ft-inches/metres.

I would appreciate opinions on a circuit and components that would do this job.

Regards Joe

 

[Pommie]

Try using the search button at the top and enter "Water Level".

Mike

 

[JimB]

It would help if we knew:

What is the liquid? Water, petrol?
Are there any solids in the liquid? Sewage?
Is the liquid always the same, or does it change?
What is the environment? An open area, river, swimming pool, enclosed tank?
Do you have access to the bottom of whatever holds the water?
You talk about ultrasonics and lasers, do you need a "non-contact" solution?

JimB

 

[Joe McGivern]

Liquid Level Measurement

It would help if we knew:

What is the liquid? Water, petrol?
Are there any solids in the liquid? Sewage?
Is the liquid always the same, or does it change?
What is the environment? An open area, river, swimming pool, enclosed tank?
Do you have access to the bottom of whatever holds the water?
You talk about ultrasonics and lasers, do you need a "non-contact" solution?

JimB
__________________
Experience is directly proportional to the value of the equipment ruined.


The liquid will contain sewage, from thIt would help if we knew:

What is the liquid? Water, petrol?
Are there any solids in the liquid? Sewage?
Is the liquid always the same, or does it change?
What is the environment? An open area, river, swimming pool, enclosed tank?
Do you have access to the bottom of whatever holds the water?
You talk about ultrasonics and lasers, do you need a "non-contact" solution?

JimB
__________________
Experience is directly proportional to the value of the equipment ruined.

Thank you JimB.
Your last line cannot be disputed.

The liquid will contain sewage and " non contact " is the preferred option. The environment is a pump sump and access will be from the top. No ,I
don't have access to the bottom of the pump sump.

 

[Joe McGivern]

Thank you Mike, I can see is another guy there with the same idea

 

[jolino]

Hi Joe, by what i know the more used solution is the ultrasonic way.
But i remember that i used in the recent past an pressure sensor.
Certainly you know how level detection works on the washing machines.
They have one pipe from the top to the bottom of the water container.
The pressure sensor is incased on the top of the pipe.
When the water level grows, the pressure inside of the pipe also grows.
So, this way you can mesure the level.
Depending of how much is the amplitude level, the range of proportional pressure must be take in account to choose the right sensor (max. pressure).
Perhabs the Motorola MPX series acomplish your needs.
I remember that this sensores have an analog output and they have diferent parts with different range pressure.
Normaly, the output is differencial but recently i see one Motorola model that have just one out. This this facilitates the work very.
Just another suggestion,

Regards, Jolino

 

[Joe McGivern]

I'd like to get more on ultrasonic or laser (non contact ) if anyone can help
Regards
Joe

 

[JimB]

I guess a lot depends on how much money you have to spend.
If you want to measure the level in a sewage sump, not a very beneign (sp?) environment, you need something which has been designed for the job and suitably ruggedised.

A quick look using our old mate Google came up with this:



Which would probably do the job, for a price my boy!

If you want a cheaper home-made solution, I have no direct experience in this area, but I guess the place to start would be with a couple of ultrasonic transducers.....

An idea just came to mind, how about adapting one of those "ultrasonic tape measures" which are readily available.
Six metres range should be OK, but whether it will work on a tank full of turds I dont know.
Try it and let us know.

JimB

 

[Joe McGivern]

Thank you JimB.
I have been looking with Google and found several possibilities. The cost is quite high for some.

I followed the "Chemresist" one ,it looks like a popssibility. Havent had time to get as price or spec on it yet.


I followed another line:- A Ti microcontroller (MSP430). The info on it was good and I'd like to have a go at making it work but it may be outside my the scope of my ability to put all the components together and make it work.