water level sensor

Discussion in 'The Projects Forum' started by sasek, Jan 21, 2010.

  1. sasek

    Thread Starter Member

    Jan 3, 2010
    i do some project to sens water lavel in tank, the way i want to used to sens water level is by using ultrasonic sensor. but i not very sure either the ultrasonic wave will pass through water or other outside effect that can effect my sensor......

    i glad if u can recommended other sensor type...

    plz hellp....thanks.....:p
  2. maxpower097

    Well-Known Member

    Feb 20, 2009
    What about using some sort of load cell and then defining the levels by weight?
  3. Duane P Wetick

    Senior Member

    Apr 23, 2009
    Ultrasonics are used for non-contact level sensing in fuel tanks, but require signal conditioning electronics; amplifier, A-D scaling etc. The best (most reliable) liquid sensing means are the ultrasonics. Do you need precise level sensing or just the presence of liquid? Your application is really dependent upon this.

    Cheers, DPW [ Everything has limitations...and I hate limitations.]
  4. hgmjr

    Retired Moderator

    Jan 28, 2005
    What is the maximum distance between empty and full in your tank?

  5. sasek

    Thread Starter Member

    Jan 3, 2010
    max distance is about 3m. i think 2 use laser sensor. here i want brief that the device in my project must be portable. if i use laser sensor i can adjust the intensity to find distance. do anyone have experience on this?????
  6. jpanhalt


    Jan 18, 2008
    The problem with lasers and water is that the reflection you sense may not be from the surface. If the laser is normal to the surface, for example, and the wavelength is not absorbed by the water, then it is most likely the reflection you sense will be from the bottom of the tank, not the top surface.

    However, if you use time of flight, and if the liquid is known (i.e., pure water), then you can determine depth based on slowing of the beam due to the refractive index. That is, the detected reflection for a full container will be "further away" than for an empty container. By knowing the refractive index (approximately 1.333 at 20°C), you can calculate the depth of water. That is a lot of work to do, though.

    Last edited: Jan 22, 2010
  7. hobbyist

    AAC Fanatic!

    Aug 10, 2008
    You prefer not to use any kind of float devise hooked to a potentiometer, of some sort?
  8. sasek

    Thread Starter Member

    Jan 3, 2010

    i more prefer if the sensor is not be attached to the tank. FYI also the depth of the water to be measure is not necessary to be accurate......... if any sensor that compatible to make the idea to sens the water depth from far become real????