Now that the customer knows what factors influence insulation resistance, let’s review how to calculate the minimum insulation resistance of a capacitor using the datasheet. For this example, part number “C1812C206K3RLC” was selected. This is an X7R with KONNEKT technology, 1812, 20µF, 25V capacitor. The datasheet specifies the insulation resistance as 500 MΩ µF, or 10 GΩ, whichever is less. To determine the minimum insulation resistance, divide the IR limit from the datasheet by the capacitance in microfarads. In this case, 500 MΩ divided by 20µF, which is equals 25 MΩ. Since 25 MΩ is less than 10 GΩ, the insulation resistance is 25 MΩ. Although the insulation resistance for each part type can be calculated from the datasheet IR limit and capacitance value, it is not necessary since all insulation resistance values are available in the KEMET part specification sheet. Note that the catalog limit for insulation resistance is at room temperature and with a charge time of 120 seconds. This method for calculating insulations resistance will be the same for every type of ceramic capacitor, regardless of the form factor, case size, and dielectric.