|MadSci Network: Engineering|
I need more details on your experimental requirements to make any specific recommendation. If the purpose of the liquid is heat transfer, the problem you will encounter is that substances which have good heat transfer characteristics typically are also good electrical conductors. If you are planning on dropping the whole circuit in the liquid, only the natural convection will provide cooling. This may or may not be adequate. In situations where water cooling of electrically live components is required, deionized (DI) water is often used. It has a resistivity on the order of 15 mega-ohm - centimeters. Water is also a good heat insulator (that's why a wet suit works), so water cooling systems usually take advantage of convection by keeping the water flowing. Distilled water, from a grocery store or pharmacy, is a "poor man's" DI water. Unless your experiment MUST be submerged, I'd try forced air cooling first. (You can just use a fan.) Monitor the temperature during longer and longer runs, and shut the system down at the first sign of an over-temperature condition. If you begin researching different liquids for cooling, the electrical specification you are interested in is resistivity (units of ohm-cm) or its reciprocal, conductivity (units of mho/cm or Siemens/cm). If you have more specific questions, contact me at firstname.lastname@example.org. Good Luck, Chris
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