This guide establishes the requirements and test methods for liquid and paste fluxes for joining by soldering of copper and copper alloy tube and fittings in plumbing, heating, air conditioning, mechanical, fire sprinkler, and other similar systems. There shall be a clear indication that in the areas of flux reaction, the sheets shall show a corrosion and residue-free surface comparable with the unwetted areas as determined by visual inspection. Samples of flux taken for the purpose of the tests listed in this specification shall be selected from the stock of the manufacturer and shall be representative of the material being evaluated. The specimen shall undergo the spreading test wherein the oven shall be equipped with a sight glass for visible control of the melting of the solder. The specimen shall then pass the aggressiveness test wherein the aggressiveness of the flux is determined by means of a resistivity test of an aqueous solution of the flux residue. The conductivity cell to be used shall be kept immersed in distilled water at ambient temperature for a given minimum number of hours before use. Resistivity tests shall be performed for both soldered and unsoldered specimen. The specimen shall then undergo corrosive test by being dipped onto ethanol.