Hey John: Chrys wrote a good description on calculating flux density a while back. Here is our version of her procedure:
4.3 Determine the amount of flux on the board. 4.3.1 Get a piece of corrugated cardboard and a weighing scale accurate to 0.01 grams.
NOTE: Use cardboard with alcohol fluxes to slow their evaporation and get good data.
4.3.2 Weigh the cardboard. 4.3.3 Run the cardboard across the fluxer. 4.3.4 Weigh the cardboard again. 4.3.5 Calculate change in weight / area of the cardboard 4.3.6 Determine flux density. 4.3.7 Ask the flux manufacturer to calculate the flux deposition as: (Change in weight / area) X % solids by weight. 4.3.8 Convert the flux deposition to micro-grams/square inch and compare it to the manufacturer's recommendation.
Good luck
Dave F
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