How to use the resistance level of a multimeter to determine the quality of an electrolytic capacito

There is generally a certain value to represent whether it is useful or not, test it.

The principle of judging the quality of the capacitor with the resistance file of the multimeter is to use the principle that the voltage at both ends of the capacitor cannot be abruptly changed.

When measuring the capacitor with the resistance level of the multimeter, the battery in the multimeter will charge the capacitor at the moment when the two meter pens touch the two pins of the capacitor respectively, because the voltage at both ends of the capacitor cannot change abruptly, at this time, the capacitor presents a low-resistance state (that is, the angle of deflection is larger) Over time, the capacitor is gradually fully charged (which is related to its time constant), and the pointer of the meter returns to infinity.

Compared with the electrolytic capacitor with a relatively large capacitance, it is necessary to choose a resistance range with a relatively low range. On the contrary, for capacitors with relatively small capacitance (such as some mica capacitors), it is necessary to choose a higher resistance range (more than x10k gear).

If the pointer cannot return to the original scale after deflection, it means that the capacitor may leak current (except for large-capacity electrolytic capacitors); If the return speed of the pointer is slow after deflection, it means that the capacitance of the capacitor is relatively large.

There are 3 ways to judge the quality of the capacitor of the multimeter, even if the multimeter does not have a capacitor block, it can be judged.

Use the multimeter resistance file to judge the quality of the capacitor, it is best to use a pointer multimeter: The two leads of the electrolytic capacitor are positive and negative, and when checking its quality, the electrolytic capacitor with a lower withstand voltage (6V or.

l0V), the resistance gear should be placed at R 100 or.

R 1k file, connect the red pen to the negative end of the capacitor, and the black pen to the positive end, then the multimeter pointer will swing, and then return to the starting position or near the starting position. Such electrolytic capacitors are good. The larger the capacity of the electrolytic capacitor, the longer the charging time and the slower the pointer swings.

Otherwise, the capacitor is bad. In addition, if the pointer keeps showing 0 resistance, it means that the capacitor has broken down and is also broken.

To measure the quality of the capacitor, it is best to use the pointer multimeter to measure, the pointer multimeter is more intuitive, the following will take the pointer multimeter as an example, talk about how to measure the quality of the capacitor.

First measure the capacitance of the capacitor, the capacity is more than 100 microfarads, dial the meter to the resistance level Rx100 gear, a few thousand microfarads or more, dial the meter to the RX10 gear, and dial the meter to the RXK file with hundreds of microfarads. When measuring, use two watch pens to measure both ends of the capacitance dissipator back and forth, and the watch hand has the following swing:

a. The watch hand swings quickly to the right (the larger the capacitance, the greater the swing angle), and slowly returns to its position, this capacitor is good.

b. The watch hand swings quickly to the right, and the full degree of the watch hand points to zero, and then stops moving, indicating that the capacitor has been broken down and short-circuited. Or the watch hand doesn't move at all, it's broken.

c. After the watch hand swings to the right, it slowly returns to the middle, indicating that the internal leakage of this capacitor Zheng Zai device is also bad.

d. If there is no multimeter, you can also use a battery and a small bulb to judge the good and bad, the way is to connect the capacitor with the battery and the small bulb in series, at this time, the bulb is on, the capacitor is bad, and it is good if it is not lit.

e, the capacity in the thousands of shouting digging Wang Wei method, the watch hand is basically not moving is good, the watch hand is full is bad.

Yes. Use the resistance file test, first short the two pins of the capacitor for discharge, and then the red watch pen is connected to the positive pole, and the black table pen is connected to the negative pole, if there is data and this data has been increasing, and finally display 1, it is generally good.

1. Estimate the capacity of microwave capacitance: it can be judged by experience or with reference to the standard capacitance of the same capacity, according to the maximum amplitude of the pointer swing.

2. Estimate the capacitance of pico-level capacitance: use R 10k gear, but only the capacitance above 1000pf can be measured. For capacitors of 1000pf or a little larger, as long as the watch hand swings slightly, the capacitance is considered sufficient.

3. Test whether the capacitor is leaking: for the capacitor of more than 1,000 microfarnes, you can use R 10 gear to quickly charge it, and preliminarily estimate the capacitance capacity, and then change it to R 1k file to continue to measure for a while, at this time, the pointer should not return, but should stop at or very close, otherwise there is leakage.

4. Adjust the function switch to 20UF or 200UF gear, the pen is in the middle two holes, and the pen will measure the capacitance poles respectively, and then its capacity will be displayed. If it is a used capacitor, it must be discharged before measuring.

How does a multimeter measure the capacity of a capacitor and judge the quality of the capacitor?

The capacitor can be used in the same meter file, that is, the gear that can produce sound, the watch pen instantly contacts the capacitor in front and back, and the two electrodes have sound, which is good.

Just a simple test.

The capacitance of the capacitor cannot be guaranteed.

Hope it helps.

1. Generally, digital multimeters have capacitance files (some have capacitance test jacks on the multimeter, and some use meter pens).

2. If there is no file test with diode symbols (the meter pen is connected to the two poles of the capacitor, if you hear a sound of the meter and then it does not sound, the meter is generally displayed as 1, and then the table pen is reversed, and the above phenomenon still appears, indicating that the capacitance is good. If the meter pen is connected to the two poles of the capacitor, the meter keeps ringing, indicating that the capacitor is broken).

Note: The number of the watch is constantly increasing during the time between the clock ringing and the display 1.

Method 2 only measures the quality of the capacitor, and cannot measure the capacity alone.

The red pen is connected to the positive pole, and the black pen is connected to the negative pole. If there is no capacitance measurement function, it is estimated by the resistance, that is, by the method of charging and discharging with the resistance level.

A digital multimeter, a multi-purpose electronic measuring instrument, generally contains functions such as ampere meter, voltmeter, ohmmeter, etc., and is sometimes called a multimeter, multimeter, multimeter, or triple meter.

DMMs are available as portable devices for basic fault diagnosis as well as devices placed on a bench, some with achievable resolutions.

Seventh, eighth. A digital multimeter (DMM) is an electronic instrument used in electrical measurements. It can have many special functions, but the main function is to measure voltage, resistance and current, digital multimeter, as a modern multi-purpose electronic measuring instrument, mainly used in physical, electrical, electronic and other measurement fields.

Accuracy] Accuracy refers to the maximum allowable error in a specific use environment. In other words, precision is all about indication.

The approximation of the measured value of the DMM to the actual value of the signal being measured.

For numeric multimeters, accuracy is usually expressed as a percentage of the reading. For example, a reading accuracy of 1% means that the actual voltage may be in between when the display of a digital multimeter is.

In the detailed specification, there may be specific values added to the basic accuracy. What it means is the number of words to be added to transform the rightmost part of the display. In the previous example, the precision might be marked as (1%+2).

Therefore, if the GMM reading is, the actual voltage will be in between.

The accuracy of the analog table is calculated as the error of the full scale, not as the reading displayed. The typical accuracy of an analog table is 2% or 3% of the full scale. The typical basic accuracy of a digital multimeter is between ( and (, or even higher) of a reading.

Digital-analogue display].

Analog pointers are slightly inferior in terms of accuracy and resolution. Because you have to estimate the position of the pointer.

Bar charts show changes and trends in signals like analog pointers. But it is more durable and reduces damage.