Corrosion Potential Setup Parameters

Here is a Corrosion Potential Setup dialog box complete with its default parameters.

Total Time

The length of the experiment. The units are seconds. The resolution is set by the Sample Period.

Sample Period

The spacing between data points. The units used for the Sample Period are seconds. The shortest Sample Period we recommend is 0.1 second. The longest Sample Period allowed is 715 seconds.The Sample Period also helps determine the Number of Points in the data curve as follows.

Number of Points = Total Time / Sample Period

The Number of Points must be less than 262 143. If you have more points, the experiment aborts just before the data-acquisition phase of the sequence.The resolution in the Total Time is controlled by the Sample Period. Times that are not integer multiples of the Sample Period are rounded down. For example, if the Sample Period is set for 8 seconds, and a Total Time of 900 seconds is requested, the actual Initial Time will be 896 seconds, which is 112 Sample Periods.

Stability

In many cases, you just want to measure until the system becomes stable (when Eoc stops drifting). The DC Corrosion software allows you to automatically terminate the open-circuit measurement when you feel that Eoc has become stable. You use the Stability parameter to tell the system your definition of a stable potential.If the absolute value of the Eoc drift-rate falls below the Stability parameter, the Corrosion Potential experiment ends immediately, disregarding the Total Time parameter. The drift rate can never fall below zero, so entering a Stability value of zero assures that the experiment will not end prematurely.The units of the Stability are mV/s. A typical value is 0.05 mV/s. The upper limit in this parameter is 8 V/s, well above the range of practical stabilities with real cells. The lower limit in the Stability parameter is set by your patience. A stability of 0.01 mV/s means that a 1 mV drift takes 100 seconds. The DC105 has to take data for nearly 100 seconds merely to resolve this small a change in potential.