What's the best way to electronically sense the level of refrigerant in a liquid line receiver? (Only 8 levels or so is enough.) Tiffany is asking me that for a future "mini mainframe" cooling system. The sensor can be either analog or digital. The refrigerant will be R410a if it makes a difference.
Is the refrigerant electrically conductive? If so, would there be any undesirable chemical reactions by passing a small amount of electricity through it? If not, is there a substantial difference between the capacitance constant of liquid and gas phase refrigerant? And what's the best way to get the signal from inside the receiver? Could a 2 piece transformer be used to pass power to the sensor and the signal to the micro? Are there better ways of sensing the level?