Monitoring Water Level in a Tank

So, if I guess this rightly, the goal is to test the sorption rate to the material?  I'm guessing what the test is.  When the material is saturated does flow stop?  What moderates the outflow such that monitoring it is informative?

So, if I guess this rightly, the goal is to test the sorption rate to the material?  I'm guessing what the test is.  When the material is saturated does flow stop?  What moderates the outflow such that monitoring it is informative?

The intent is to see what is the final absorption of the material after six hours ( weight material before test and weight after test, but this is outside the scope of the project).  The flow will not stop for set time which is 90 percent of the time is six hours.  Rarely where we have to set the test time less or more than six hours.

Haytham

Since this seems to be a very tightly controlled 'project' can you enlighten us what is your involvement.

ie Is this part of your practical exam for study, are you assisting someone wanting to carry out these experiments.??

The tank dimensions will make a difference in terms of accuracy, speed of delivery (pressure) and possible solutions.

The fill to 15 inches is simple ...use a float switch.

The level could be done with a float and wire/string that rotates a potentiometer.

There are numerous Arduino data loggers on the internet, as you will find wioth a quick search.

I'd also suggest adding a RTC (Real Time Clock) and you may wish to look at some of the boards that already have this.

http://www.seeedstudio.com/depot/Seeeduino-Stalker-v3-p-1882.html?cPath=6_7

Mark

Mark, this is a test that I routinely do in the lab for clients.  The lab is  my business.  My lab technician has to baby sit the test the entire day.

I can have a minimum wage person watch and record the test, but I cant do that as we engineers market our personal as experienced and professional.

My technician makes more money than myself (like most small businesses).  So I want to cut expenses as I am tired of making minimum wages.

I have been talking with Don regarding this, but it seems he knows too much.  His ideas are just above my head.

I bought several controllers and the e-tape and another sensor, but no dice.

The intent is to see if I can make a professional system out of this test, as I have to describe the tools and devices used in the test.  Now its just a cup, measuring tape and I-phone timer.

Okay

I wanted to be sure I wasn't doing someone homework ...as is often the case on this site.

Can you provide the tank dimensions and possibly the High and Low water levels wrt to the tank bottom.

Can we assume that if you have a very absorbent material, the time could get reduced to 20 mins, rather than making a really long measuring system.??

Don's idea is for a float system.

You could achive the same with http://www.seeedstudio.com/depot/water-level-switch-p-565.html

I know on stock cars they used to slip a cable tie or oring around the shock absorber shaft to measure the amount of travel.

You could use something similar to measure the drop and then calculate the volume.

Would that be a suitable means.

I also have to go but will be back later.

Mark

The size of the tank varies (height and diameter, client usually provide).  Volume calculation is not needed.  The reported results of the test is the drop of water vs time.

Yes the time interval can change from few seconds between readings to as much as 30 minutes.  The 30 minutes is the max time usually used and its 90 percent of the tests are run every 30 minutes.

I want to put a digital flow meter (not required by the test) but it helps me to verify calcs.  I am going to try my best effort to use a controller and sensor.  Float system may be questionable if someone reviews the tools used in the test and can draw comments.  If electronics used, no one can squeak.

One comment Don used: "MK can do it but he wants money".  I don't mind paying for time put in to program the system.  I put my phone number on the diagram earlier.  If you or Don wants to take a stab at it, let me know.  Regards

Haytham

Because the clients supply the tank this makes it quite variable, and difficult to arrange.

Also if the client provides a tank that is tall, then the pressure is going to be greater ...

Flowmeters are fine if you have a reasonable flow. Their accuracy gets less as the rates drop.

So based on some of the previous results what sort of amount in 30 mins are we talking about.?

I can understand your desire to use electronics given the variance in the supplied material.

What about if you made a header tank that was used to fill the clients tank.

You attach a float switch to the 'clients' tank and at regular intervals replace the liquid in the clients tank, from your header tank.

You measure the drop in your tank and use your system to record that drop.

At some point before the test a calibration should be done.

I would suggest setting it up, draining a measured amount out, and checking the electronic recording.

You could store that and then apply the figure into the software.

Before engaging anyone to write code, the design needs to be finalised (which you have started on ).

Mark

Haytham

One of the reasons for a seperate tank is the ability to use a weighing device.

Each litre of water weighs 1 kg, so you have the ability to measure with reasonable accuracy how much water you have passed to the 'clients' tank.

50kg  http://www.phidgets.com/products.php?category=34&product_id=3135_0

20kg  Phidgets Inc. - 3134_0 - Micro Load Cell (0-20kg) - CZL635

Mark

D_Hersey

It seems phidgets also have many other devices for Hydroponics at reasonable prices.