How to use pointer multimeter and insulation resistance meter to detect the voltage resistance of fixed capacitors and mica capacitors.
1.The method of judging the quality of fixed capacitors by pointer universal meter resistance measurement method.
Table 1 is to use MF- 500 multimeter to detect the normal charge and discharge resistance of various capacitors, which can be used as a reference for the estimation of capacitance. For electrolytic capacitors, the measured values of black watch pen positive electrode and red watch pen negative pole shall prevail. Electrolytic capacitors should be measured after discharge.
2.The method of using pointer multimeter and insulation resistance meter to detect the voltage resistance of fixed capacitors.
First, the measurement method.
When measuring the voltage of the capacitor, the insulation resistance meter shall be in series with a high back voltage diode, and the withstand voltage shall be greater than 500V (to prevent the amount of electricity charged by the capacitor from being returned to the insulation resistance meter so that damage the insulation resistance meter), According to the method of measuring capacitor withstand voltage by insulated resistor meter shown in Fig. 1, V is the voltage gear position of pointer multimeter.
Then shake the insulation resistance meter quickly, and the voltage meter value will slowly rise until it does not rise, then the indicator value of the voltage meter is the withstand voltage value of the capacitor.
The method of measuring capacitor withstand voltage with pointer multimeter and insulation resistance meter.
Second, the problems that must be paid attention to.
(1). After the capacitor is measured, discharge should be carried out in time (the discharge method is the same as above), otherwise it will be electrocuted due to carelessness.
(2). In order to measure capacitors, used the insulation resistance meter, the insulation resistance meter with high voltage should be selected to be suitable for high voltage capacitors, such as 10000 V or 2500 V.
3.Use a digital multimeter to measure the quality of mica capacitors.
When using a digital multimeter to measure and screen mica capacitors, the measuring range of the meter should be reasonably selected according to the capacitance, and the zero-adjustment knob should be adjusted so that the initial value (that is, the no-load capacitance value) is 000 or-000. Step by step, the mica capacitance can be plugged into C test hole to measure its capacitance value (taking DT890 digital multimeter as an example).
First, measure the reading capacity value.
When the capacitance is inserted into C hole, the capacity of the measured capacitance will be shown on the digital multimeter. Write down this value to see if it is consistent with the nominal value. If it meets the requirements, check the following method to detect its defects and temperature characteristics.
Second, pressure measurement.
To keep the above measurement state unchanged, the capacitance capacity should not change when the bamboo clothing clip or plastic clip is used on the measured mica capacitance (that is, applied the external force on the capacitor). If the capacitance capacity will change, it means that the capacitance quality is not good, there is a gap between the internal lamination, cannot be used.
Third, heating measurement.
When the measured capacitance is kept unchanged, use the hair dryer to heat the measured capacitance to 60 ~ 80C gradually. at the same time, observe whether the reading of the meter will change. If the capacitor quality is qualified, the reading on the table is stable and there is no significant change. If the reading on the table will jump obviously in the process of gradually heating the capacitance, it indicates that the temperature characteristics of the measured capacitance are poor.
If you want to know more, our website has product specifications for the voltage resistance of fixed capacitors and mica capacitors, you can go to ALLICDATA ELECTRONICS LIMITED to get more information