Lou: I have some slide rules for use with a Hull cell, that tells you what the current density at any given point on the Hull cell panel is for a given amperage through the bath. In other words, you set the amperage that you are plating the Hull cell at, and then put the panel next to the slide rule, and this tells you the current density at every point on the Hull Cell panel. These puppies were supplied to us by our Licensee in England, W. Canning Ltd. I suspect that these are what Mike Barmuta of Fluke was referring to. If you want one, for free, and at no extra cost, contact me. Rudy Sedlak RD Chemical Company Phone 1-888-RDCHEM1 Fax 415-962-0370