Can I used your pressure sensors to measure air pressure inside my Sealed ballast tank? Im having a hard time measuring the volume on my sealed ballast tank using other methods. and would like to measure the volume using boyles law.
Got a question … you say “Sealed” ballast tank. First of all, what is in your tanks and are they totally sealed as in you do not allow movement in or out of the units?
Just trying to get a grasp on your question. If you are looking at volume based upon pressure, the tanks will feel a decrease in volume as the ROV dives deeper to some degree. You might be better off using something that won’t drive false values such as relying on a compressible gas to do those calculations.
Im using the tank to store water in order to change my ROVs buoyancy at any time. but im having a hard time on how can I measure the volume of current liquid inside the tank to determine my buoyancy state underwater.
Well one sleeze method would be a “float tube”. If you make a tube with holes in it that basically secure a low density material that you don’t have to be that paranoid about crushing … at least not at the depths you are going to go at … and the float has a small magnet in it. You could use Hall sensors etc. along the tube to determine an approximate “level”.
If you need something were you are counting very small amounts of fluid change … that makes life tougher because you have to deal with ROV inclination skewing your true fluid level etc.
I have seen Ultrasonics used to measure tank levels on large ships that had mixed fluid tanks such as waste water / oil and they were looking for the break line between the fluids and a whole range of various applications.
Are you pressure blowing water out of your tanks or what? Curious as to how you are venting / flooding and pumping the tanks down.
We will consider that.
We are planning to use a high pressure gear pump rated 3.8Bar.
I’ve just seen this topic and have a similar issue.
I’m currently working on a variable buoyancy system that would allow a heavily weighted sensor to sit on the seabed and periodically to float up. The ballast tank will be filled from a pressurised air cylinder displacing water from the tank enabling the sensor platform to rise. Conversely air will be vented out from the tank and water. to allow it to sink.
I’m looking for subsea solenoid operated vent and fill valves that would operate in seawater down to a depth of 300m. I’d be grateful if anyone could provide any suggestions where to look. All the valves I’ve seen are intended to work in a dry environment not exposed to seawater at depth.
Thanks.