Cathode Area:
An easy way to check this to get your setup working with your usual 4 plates, and wait 10-15 minutes until some anodize has formed and the voltage starts to settle down. Note the voltage and current. Then remove or disconnect one plate. You should see the voltage go up a bit, but the current stays the same. Then do the same with another plate. If the current does change, it indicates that CC control has been compromised. The difference in voltage is proportional to the increase in power dissipation caused by the reduction in cathode area in the anodizing circuit.
Power (Watts) = Volts (V) x Current (A)
I should have thought of this earlier, this will tell you about how much the racking is compromising CC control. If you see little or no change in current with less cathode, the only electrical downside to racking is the added power dissipation. If you see a substantial change, you probably have a problem. M_D should try this too, its quick, easy, and will disrupt your operation for only a few minutes.
I'll describe the pump and chiller I'm using later.
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