MESR-100 JINGYAN AutoRanging Capacitor ESR Low Ohm Meter
JINGYAN MESR-100Autoranging capacitor ESR and Low Ohm Meter
Measuring range from 0.01 to 100.0R, support IN CIRCUIT Testing.
Using true 100KHz square wave to measure the ESR value, which is equal to the testing method of capacitor manufacturer.
In the market, there is some technique using short pulse method to testing, but the value will be varying vs the capacitance and sometimes reading is different from the manufacturer's value.
What is ESR of capacitor?
There is a series resistor inside capacitor, using 100kHz to remove the impedence 1/(2*pi*F*C), the impedence become small, and we can then measure the true series resistor value.
A bad E-capacitor will have larger ESR and create large ripple rather than filering noise. Normally it is smaller then 1 ohm.
Using this theory, we can measure the capacitor is bad/ damaged or good in condition.
Because our ESR meter only apply less than 15mV DC or pk to pk on a good capacitor, so we can use it as in circuit test. Because this low voltage, it can not turn on the semiconductor inside a circuit under testing.
During repairing TV, LCD, Audio board, etc. we can in circuit testing the capacitor is good or not.
*Dual terminal, for fast and easy inspect general capacitor or resistor, a printed ESR table for fast check