MTR100: Underwater Cameras, Lights and Ocean Landers
about topside luminaire design, including the use of heat transfer material behind the PCB to carry the heat away from the LEDs (google “CREE LED Luminaire Design Guide”). LEDs are completely pressure tolerant as they have no compressible volume. A pressure compensating fluid, such as mineral oil may be used. Avoid silicone oil has the cast dome on an LED is often silicone, and may be affected by immersion in a fluid of a similar nature.Tip: A reasonably good 30-watt, 2600 lumen LED array is <$10 and 12-24vdc input LED driver is <$9 plus shipping at <www.mpja.com>.If using
Lander Lab #5: Lithium Polymer Batteries
, they are pressure tolerant. There are no compressible materials on the interior so the rate of chemical reaction is unaffected by pressure. The matching BMS protection circuitry is likewise made of pressure tolerant components (See next section). I have immersed both in bags filled with mineral oil and tested them to 18,000-psi. They held up fine.Placing a pressure compensated LiPo battery outside the hull means you only subtract the water weight from the buoyancy budget, rather than the air weight when it’s inside the hull. Just a SWAG, but for the same amount of buoyancy
Reader Feedback: Lander Lab - Buoyancy
the net mass remains the same, thereby changing density to some value greater or less than 1. It would take a smaller volume and less energy if the material were a "liquid syntactic” with a lower specific gravity, as you coin the term.As one suggestion for your application, I use mineral oil (baby oil) for a number of p-comp applications. It has a specific gravity of 0.845-0.905, and is about as benign an oil as you can find.From Kevin Ulmer:“Yes, I think the version of Alvin I dove in back in the early 70’s used mercury as did Cousteau’s diving saucer.&ldquo
Lander Lab #3: Buoyancy
training videos.Rather than locking glass microspheres in hard epoxy, it may be possible to suspended them in oil, filing the interstitial space with a positively buoyant fluid, then use that mixture to fill a soft plastic polyethylene bottle. The hollow microspheres are buoyant, the oil is buoyant (mineral oil has a specific gravity of around 0.88). No chance of inclusions, any captured air will be compressed to nothing. I haven’t tried this yet, but it seems like it will work.« Le petit baigneur »A young French student, Jonah Royer, has written me with some ideas he has been
The Troubled History of Protecting Marine Assets
in a restricted area and dragged a Pertamina pipeline causing it to burst. In Port O’Connor, Texas, a dredge caught on fire after hitting a subsea gas pipeline, and in the Straits of Mackinac, on The Great Lakes, a dragging anchor dented a major pipeline and damaged electric cables causing a mineral oil leak.On December 23, 2019, Malta lost power for 3 hours after a vessel’s anchor cut a power line to the country. The cost of repair and mitigation is estimated to be over 20 million euros.As recently as January 9, 2020, 14 countries in West Africa experienced massive telecom disruption when
600 Gallons of Coolant Spills into Straits of Mackinac
Hundreds of gallons of mineral oil has been released from a leaking underwater utility line in Michigan’s Straits of Mackinac, this week. Initial reports from the responsible party, American Transmission Company (ATC), indicate that approximately 600 gallons of product has been released, with maximum spill potential of more than 4,000 gallons. The U.S. Coast Guard said it has established a Unified Command comprised of Michigan Department of Environmental Quality, county emergency managers, local tribes, the National Oceanographic and Atmospheric Administration, U.S.
Did Dispersants Help Responders Breathe Easier at Deepwater Horizon?
the midst of the crisis, with a priority and focus on controlling the spill and mitigating damages, scientists were not allowed the time to design and implement robust experiments to measure the impacts of the dispersant injection. The dispersant, Corexit EC9500A, roughly resembles a mix of mineral oil, windshield-wiper fluid, and household dish detergent. During a typical oil tanker accident, this dispersant fluid might be applied to the sea surface to cause oil slicks to break up into smaller droplets that dissipate into waters of the open sea, so that less oil reaches ecologically sensitive
New 300L Fluid Bath from Guildline
. The new 5600 Series larger design was implemented in response to customer requests for a larger fluid bath. The 5600 Series has 50, 75 or 100L configurations currently available. The bath uses an EMI shielded fiberglass tank allowing for multiple fluids including salt water, mineral oil and freshwater. This 5600 model comes as two separate units: the 300 liter tank; and a separate mechanical housing that contains the pump, compressor, heat exchanger and control electronics. The two units are connected by insulated flexible hosing, and this unique modular design feature, together
February 2025
