Abstract: A method for testing a heat transfer fluid based on a charged wire test (CWT) includes applying and measuring discharge current through a test circuit formed when a cathode and an anode are at least partially immersed in the heat transfer fluid in a container and a voltmeter coupled to the cathode and the anode is turned on during the CWT. The method includes measuring temperature of the heat transfer fluid during the CWT, determining a current profile based on the measured discharge current, and determining a temperature profile based on the measured temperature. The method includes determining a pass/fail status and/or a rank status of the heat transfer fluid based on pass/fail criteria based on the current profile and the temperature profile during an entire duration of the CWT.

Abstract: A heat transfer fluid for electrical applications includes water soluble glycol 5 wt. % to 98 wt. %, demineralized water 0 wt. % to 95 wt. %, and a total dissolved solid inorganic additive content in the heat transfer fluid of 0.1 wt. % to 2 wt. %. The electrical conductivity of the heat transfer fluid is 100 ?S/cm to 5000 ?S/cm.