The EIS Data Curve

ZCURVE

The tag identifies the data set as a ZCURVE datatype. The Framework™ exclusively uses the ZCURVE datatype. Other experiments, such as the DC Corrosion test techniques, produce other data types.

The first line following the datatype is a set of descriptive column headings. These headings are for file readability only. The EIS software analysis GScripts do not use the column headings to identify data positions within the curve. Click on the headings below to get a description.

ZCURVE TABLE

Pt 1Point Number
The numbers in the first column, under the column label Pt, are data-point numbers. As is typical in computer programs, EIS software numbers the data points starting with zero, not one. The first data point recorded is stored as the “zeroth” point.The data-point numbers for a normal EIS software data file are always sequential integers. Edited data can have gaps in the point-number sequence. This creates no problems in the analysis GScripts. If you write your own data-manipulation program, we recommend that you also allow for non-sequential point numbers.		 Time2The second column in the CURVE datatype is time. The column label is T. The times are in seconds since the start of data-curve acquisition. Time is reported in all Framework data files, even if it is not a variable in a experiment. Freq.3This column is Frequency, and the column label is Freq. The frequencies are in Hz. Zreal4Zreal, Zimag, Zmod and Zphz These columns are the measured impedance. The impedance is represented in both complex form and polar notation. For a capacitor, Zimag and Zphz are negative. Zimag5‘Zreal, Zimag, Zmod and Zphz These columns are the measured impedance. The impedance is represented in both complex form and polar notation. For a capacitor, Zimag and Zphz are negative. Zsig6Zreal, Zimag, Zmod and Zphz These columns are the measured impedance. The impedance is represented in both complex form and polar notation. For a capacitor, Zimag and Zphz are negative. Zmod7Zreal, Zimag, Zmod and Zphz These columns are the measured impedance. The impedance is represented in both complex form and polar notation. For a capacitor, Zimag and Zphz are negative. Zphz8Zreal, Zimag, Zmod and Zphz These columns are the measured impedance. The impedance is represented in both complex form and polar notation. For a capacitor, Zimag and Zphz are negative. Idc9Idc and Vdc These columns are the measured DC current and voltage. These quantities are measured at each frequency, because they are required in the autoranging decision. Vdc10Idc and Vdc These columns are the measured DC current and voltage. These quantities are measured at each frequency, because they are required in the autoranging decision. IRange11Irange This is the potentiostat current range used to record the data point. It is included as a troubleshooting tool. It is not required. Gamry Instruments reserves the right to drop this field from the data file in future software releases.
# s Hz ohm ohm V ohm ° A V
0 7 5000 201.039 -33.332 1 203.784 -9.41393 8.89475E-006 0.005877 4
1 12 4032.26 198.969 -41.875 1 203.328 -11.885 4.45025E-006 0.004065 4
2 17 3205.13 201.301 -49.936 1 207.402 -13.9319 8.30867E-006 0.005587 4