The sensor would be mounted inside the water tank , the water tanks are standard 500 ltrs and made of plastic material , i need to measure the level of water so a DIY will work for making low cost or if not possible then a ready made one.
also, what about ultrasonic sensor's and their applicability in this type of project?
I'd go with a standard fuel tank float sensor for a car; can be bought all over the internet relatively cheaply, or if you want to make your own, the basic priciple is a float with a hinged arm acting as a very simple pot:
If you're using a standard 500 litre intermediate bulk container (i.e. a cube) then there's not even a need for any processing - resistance of your pot should be directly proportional to water level.
If you're using a standard 500 litre intermediate bulk container (i.e. a cube) then there's not even a need for any processing - resistance of your pot should be directly proportional to water level.
The tank is cylindrical.
Sorry I think I made that unclear; what I meant is that using a basic float sensor, the amount of liquid in your tank will just be a straight n * (the resistance on the pot) if it's a constant shape, but you'd need to use a calibration curve if you had a strange tank shape e.g:
Calibration can be done in software not a big deal but what about the fact that the liquid will be all the time water! and the float systems in these fuel tanks are made keeping in mind they would be loaded under a fuel tank only and they just do not expect water? so dependency may go low.
As it's just a float attached to a hinge, the liquid type shouldn't matter. There are loads of liquid level sensors of course (60+ options here at http://uk.mouser.com/Sensors/Liquid-Level-Sensors/_/N-zqig/) but as you suggested doing it as a cheap DIY job, I thought a float+hinge+pot was the most simple answer!
That is easy to do but ,The concealment of POT in water? any suggestions on that?
Try here - http://vkwarehouse.blogspot.in/2012/03/diy-capacitive-liquid-sensor.html
Im not measuring a thin surface container , the water tanks has a very thick body , do you think the capacitive will work out there , Hardly
Another approach might be to measure the weight change of the tank between full and empty.
weight change
Hmm man.. that is heck of a short cut and a cheap idea, I can use Force Sensors for that but they are not good at defining weight consistently but then it makes no sense to measure precise weight as i just need to feed the processor with some differential values to depict the change.
What you say ?how much weight these force sensors can handle?
What you say ?how much weight these force sensors can handle?
Depends on what force sensors you are talking about. You could make a simple slightly offset teeter-totter platform for the tank to sit on so a force sensor would not have to take much actual force. A inexpensive mechanical bathroom scale could also be placed under a corner of the tank. Replace the rotating dial in the scale with a small pot. Lots of different ways, from mild to wild.
Depends on what force sensors you are talking about.
Can you shortlist something from here >> rhydoLABZ a and tell me what would be a desired system for level sensing in a 500LTR big black tank.
I think I'd go for a float sensor, still - but not a "swinging arm" one; a 500 L tank is not small, so I don't think a swinging arm sensor would work. What would work though is to use a multi-turn potentiometer, possibly geared in such a way that your "float", resting on the surface of the water, is slightly heavier than a counterbalance weight. The potentiometer, gearbox, and counterbalance weight all are located outside of the tank. The float is connected via a cable wrapped around a knurled shaft (or between a couple of rubber pinch rollers), which is attached to the potentiometer via gearing (so that it takes multiple turns of the gearing to turn the potentiometer slightly); the counterbalance weight is attached to the other end of the cable.
As the water rises (as the tank is filled), the shaft rotates one way, as it falls (tank being emptied) it rotates the other way. I'm actually pretty certain there are more than a few commercial instances of such devices out there.
You might also look here for some other ideas - which might be possible to make in a DIY manner:
Hi thanks for the inputs:
I have seen this >> http://www.open-electronics.org/water-tank-level-display-with-arduino/ working with a ULTRASONIC sensor , its successful but what about being successful in the 500 LTR tank casing it is very deep and wide? can you guys put some light on this method?
EDIT: But then WIKI says this about ultrasonic sensors "Ultrasonic level sensors are also affected by the changing speed of sound due to moisture, temperature, and pressures."
ANOTHER IDEA - What about amplifying the range of a 50cm reading infrared obstacle sensor? like >> Probots - Largest DIY Electronics, Robotics & Engineering Parts Buy Online Store Buy Online India
I would go for a float type sensor but aim to keep the pot dry. Either encapsulate and seal it really well, or put the electrical part outside the tank and use a pushrod/lever to operate it remotely from the float.
I would go for a float type sensor but aim to keep the pot dry. Either encapsulate and seal it really well, or put the electrical part outside the tank and use a pushrod/lever to operate it remotely from the float.
any possible links to the parts that i use to make the float work in the tank?
Do you have wire coat hangers and expanded polystyrene foam in that part of the world? There's nothing fancy needed here, just an arm with a pivot at one end and a float at the other. Connect a simple pushrod from the arm to move/turn your potentiometer and you're done.
What bout the length of the shaft , that is the main problem or I'm not able lo make out the way to mount the float. If I mount it on the bottom of the tank then the shaft needs to be a lot lengthy or after sometime the measurement can happen when kid float is fully under the water.