Devices based on the use of Ohm’s law ratios are simpler in terms of circuit implementation and automated measurement results. Briefly about the transistor tester, many praise it and say that it makes expensive devices. Recording and statistics function < br />Manual / automatic operation So there is something to compare with. I repaired radios and rebuilt I needed to measure low capacitances, from 1pF, stability of readings, so that they would not float during the measurement and the same result would be consistently shown when re-measured. The higher the ESR, the greater the initial "voltage surge" at the moment the current is applied.
I’ll make a reservation right away, I didn’t study in a profession related to electronics, but from childhood I studied, read, learned everything myself, so I don’t have professional knowledge in this area and I apologize in advance if something is not so. The capacitance is measured by the standard method – the charge time of the capacitor with direct current is measured to a certain voltage level (in this case, up to 0.2 V) and the capacitance is calculated using the formula C \u003d t * I / U. Voltage, current and phase shift between them are measured in a selected section of the circuit. Before that, you had to shovel boards with a considerable number of capacitors, it took a long time until you get to the very one and it’s not a fact that it is the last one. The instruction for the device, purely in hard Chinese, I hardly managed to find in English, here is the link, and as I understand it, a certificate or statement of verification from Uncle Liao, a warranty card, a brochure from UNI-T and a disk. Those who purposefully take such devices, the functions of the buttons will be intuitive. This is a review of a really 4-wire bridge immitance meter from Uncle Liao. The RCL measurement accuracy is so-so, for domestic purposes it will do, this is a price for versatility. Such devices can only operate at fixed frequencies. The ESR measurement error in this case will be 0.02 ohm. Sometimes it was rational to change all the capacitors along the search path or to give up on new ones at once. When using this method, the ESR of capacitors is small
capacitance (1 … 10 microfarads) will be slightly higher than their real ESR due to the fact that in a time equal to the duration of the test pulse, the capacitor will have time to charge up to a certain voltage level, which gives an increased error in measuring ESR with a small capacitance. The search for an affordable and ideal LCR meter. Audible / visual alarm and tolerance counting function For example, a capacitor with a capacity of 1 μF when charged with a current of 30 mA in 2 μs will have time to discharge to a voltage of U = t * I / C = 60 mV. Above the input connectors is a standard warning that, before measurements, discharge the capacitor. For me, this device is a pumped version of the E7-22. The first is short DC pulses applied to the capacitor under test. An appropriate device was purchased, and it helped to find bad capacitors, but still its accuracy was approximate, there was no talk of any accurate measurements of ESR and capacitance. I have always been interested in electronics and this is my hobby. Packaging. The device arrived without special packaging, a standard package from AliExpress, a bubble wrap and a gray box with branded inscriptions from UNI-T. An ideal capacitor with zero ESR will start charging at zero voltage. Automatically detects the type of component and selects the appropriate measurement parameters It all started with the fact that I found out about the existence of devices that test capacitors without desoldering. This device is highly specialized and you may not need it at all, you can get by with a conventional transistor tester. 2.8 inch TFT LCD I still don’t understand why it is needed, who will tell you. We have in our hands the older model of this line. With DCR function (DC resistance measurement). Then I learned about ESR and that it can be used to evaluate the quality of capacitors. For all the time, devices have accumulated: ESR micro v5.0 s, MLC500, YR1035, XJW01, HB-15 tweezers, P5030, and finally this device has arrived from the review. At the same current, a 100 µF capacitor will charge up to 0.6 mV in 2 µs. Please note that measuring the capacitance of capacitors with increased ESR in this way gives a slightly underestimated value (due to the initial voltage drop mentioned above). Implementation
digital instruments for measuring the parameters of electrical circuits based on bridge methods is accompanied by a noticeable complication of their circuitry and automation of balancing processes. Who measures the current in the outlet or at least once measured the charged capacitor in the transistor tester, you better forget about this device for now. The same younger brother UT612 rides in branded packaging. Characteristics.
Inscriptions highlighted in white are switched by a short press, yellow by a long press. Let’s figure it out. This "voltage surge" is analyzed and converted into ESR. The measured values ​​are used to calculate the circuit parameters. By this time, I had already decided on the minimum requirements for the device. The second way is to measure capacitance on alternating current using a bridge https://jiji.com.et/cars/toyota-4runner circuit. Which will correspond to the measured ESR=U/I=60/30=2 ohms.

UNI-T UT622E LCR Meter Overview. The miracle did not happen.

Found out that there are several ways to measure and evaluate the quality of capacitors. This is an adequate accuracy, ESR measurement, measurement without desoldering, because. Complete set. The device itself, Kelvin probes, cable, calibration plate, mains power supply (5V, 1A, for Chinese sockets), mini USB cable, it is not clear what prevented to put type-C. It measures from 28pF, an incomprehensible Vloss indicator, it’s not really written about it and what it gives, it seems like it’s the loss tangent (tg δ), but compared with devices that show this angle, it’s not even close, it gives out some bad capacitors as good. The principle of measurement of such immittance meters is based on the analysis of the passage of a test signal (usually sinusoidal) with a given frequency through the circuit being measured, which has a complex resistance. Then it’s better, the bundle of papers is already their brand. Tolerance comparison mode Usually they have branded packaging of red-gray color, and here the savings are incomprehensible, although the device is not cheap. The principle of operation of bridge meters of immitance is based on the use of a measuring bridge, for balancing which, the device contains sets of exemplary active and reactive (capacitive) resistances. The operating frequency voltage from the internal generator is supplied to the measured object.