TIDUEZ8C december 2022 – june 2023
Figure 3-3 and Figure 3-4 show the relative error for the 400-V and 800-V tests. The color scheme in the tables from green over yellow to red shows the small to big relative errors and is used to indicate performance in different areas of the measurement range. The test results show that the measurement accuracy is best in the important range of 20 kΩ to 200 kΩ, where the insulation faults must be detected. With higher insulation resistance values, the accuracy falls off, especially above 1 MΩ. This reduction in accuracy is not a problem since in this range the insulation is far above the fault and warning levels. For this reason, the actual software for this reference design does not return values above 1 MΩ. Every calculation result which indicates a resistance higher than 1 MΩ is set to 1 MΩ. This feature was disabled for the measurements in the following tables.