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Accurately dispense liquid volumes

  1. Feb 14, 2012 #1
    I am considering the economic viability of a project that must accurately (within a tolerance of, say, 0.5ml) dispense volumes of water from a tank at a constant volumetric flow rate of around 50ml/s.

    Within the tank, the water may be held at pressures between 1 and 6bar; and at temperatures between 4 and 18°C. The temperature should not be changed by more than 0.5°C during the dispensing.

    The volume to be dispensed will be controlled electronically (between 10 and 250ml).

    It is not clear to me what would be the simplest approach, from a pressure regulator in series with a timed valve (which I doubt could achieve the desired accuracy) to some advanced pumping arrangement controlled by electronic flow measurement devices. I imagine it could also be possible to determine the volume of water dispensed via changes in volume remaining in the tank; e.g. the tank could be weighed or include a floating ball measure.

    Aside from the criteria detailed above, other considerations include: minimising cost (obviously); ease of regular cleaning (the water is for human consumption); and minimising the physical size of the device.

    I would be extremely grateful for your suggestions.
  2. jcsd
  3. Feb 19, 2012 #2
    I dont understand? If you wish to measure your water that accurate then could you not just use a graduated cylinder with a level sensor on the side?

    This idea seems very odd to me, please explain as I must be missing something?
  4. Feb 19, 2012 #3


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    Anestheistiologists use automated fluid (anesthesia) dispensers to control the infusion of volumes of the drugs into patients.
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