This presentation utilizes Origin's layering feature to display a 3D color map surface and a 2D line plot in the same graph. The 3D and 2D data are combined to illustrate the problem associated with measurement of electrical impedance under adverse conditions, specifically at low frequencies and at low values of the AC signal used to measure the impedance response.
The 3D surface graph uses a 3 color mix of red (high), green (middle), and blue (low) to chart the response of a text fixture to both frequency and applied potential, using a Solartron 1296 analyzer. The red plateau region is the normal response of the fixture containing a combination of resistors and capacitors, and is in agreement with theoretical predictions. The green spike demonstrates a decrease in the measured impedance. The graph has been rotated about the vertical axis to enhance the view of this spike region. The 2D line plot shows the impedance of a single 25.3 kOhm resistor at 100 Hz as a function of applied AC voltage. Again, at low voltage values the data shows noise and deviation from the theoretical value.