This is an old revision of the document!
Standard capacitor worst-case electrolytic ESR table download the PDF Version by Clicking on the chart
Obviously the value in the table are in ohms!
ESR is the abbreviation for “Equivalent Series Resistance”, sometimes referred to as “Effective Series Resistance”. ESR is a DYNAMIC (AC) property of a capacitor and cannot be measured with a DC ohm meter. ESR can be considered to be the total series NON-REACTIVE AC resistance of a capacitor. ESR includes the DC resistance of the leads, DC resistance of the connections to the dielectric, capacitor plate resistance, and the IN-PHASE AC resistance of the dielectric material. The combination of components that make up ESR are symbolized by a resistor in series with a capacitor.
Why check ESR? An increase in ESR is the first indicator of a bad capacitor. As a capacitor fails its’ ESR increases until ESR reaches infinity, total failure. By measuring ESR one can locate failing capacitors before they quit completely. Often a capacitor will measure GOOD with a capacitance reading meter yet it will actually be BAD due to increased ESR! Todays' modern circuits are designed with low ESR parts. Checking ESR guarantees a reliable test of a capacitors health.
