Fnirsi LC1020E LCR Meter (Review)

Anyone who regularly builds circuits or repairs devices can usually make good use of an LCR meter. With such an instrument, you can accurately measure resistors, capacitors, and coils. This is not only useful for checking known or unknown parts, but also for testing old components (such as electrolytic capacitors) to see if they are still working properly. However, a usable LCR meter will cost you at least 150 euros (and that is not even considering professional devices), which often prevents you from purchasing such a meter. The Chinese manufacturer Fnirsi, known for its wide range of electronics measuring equipment at competitive prices, is now also introducing a “real” LCR meter for a low price, namely 70 euros. And truly unique for this price: you even get a set of Kelvin test clips included (more on that later).

This Is What’s in the Box

The meter itself has the dimensions of a standard multimeter, measuring approximately 18x9x3.5 cm. As with most devices from this manufacturer, the meter, finished in black and light blue, is neatly finished. On the front is a large, easy-to-read 2.8-inch display, with a number of push buttons for operation below it. At the bottom are two sets of measurement connections: three test slots into which you can directly insert components or connect Kelvin clips, and three banana plug sockets for plugging in standard test leads. On the side is a USB-C port for charging and firmware upgrades, and on the back is a fold-out stand to set the meter upright.
 

As we have come to expect from Fnirsi, quite a few accessories are included. In this case, these are a USB charging cable, a set of test leads similar to those found on a multimeter, a short-circuit plate for calibration, a bilingual manual, and – most importantly! — a set of Kelvin test clips. These are special test clamps where the tip of each clamp is connected to a separate terminal on the meter: the two measurement inputs and two sense inputs. In this way, the voltage drop in the test cables is compensated because the voltage at the object being measured is fed back to the sense terminals directly at the clamping points. With LCR meters costing a few hundred euros, this is usually an extra that you have to purchase separately.

What Can You Do with It?

When measuring passive components, one examines which theoretical components make up such a component. The equivalent circuit of a capacitor, inductor, or resistor consists of a reactive component (capacitance or inductance) with a resistor. This can be implemented as a series or a parallel circuit. This LCR meter features both measurement options; in auto mode, the meter selects the best combination itself. The LC1020E's display shows two values for the measured component: at the top is the component's main value (resistance, capacitance, or inductance), while below that, a "loss value" is displayed indicating the extent to which the component behaves ideally. This can be done in various ways: X (reactance), D (dissipation factor), Q (quality factor), phi (phase angle), or ESR (equivalent series resistance). In fact, it all concerns the same value, just calculated and displayed in different ways. In auto mode, the meter determines the type of component itself; for a capacitor, the dissipation factor is displayed automatically, and for an inductor, the Q-factor. For a resistor, the reactance is displayed. You can manually switch to a different display mode.

Other Measurement Options

When measuring a passive component, the frequency at which the value and properties are measured is important. With resistors, frequency-dependent behaviour is usually minimal, but with capacitors and inductors, it plays a major role. With the LC1020E, the user can set the measurement frequency to 100 Hz, 120 Hz, 1 kHz, 10 kHz, and 100 kHz. The latter value is particularly interesting if you want to measure capacitors for switching power supplies. Many cheaper LCR meters do not have this option. Furthermore, with the LC1020E, you can set the measurement voltage to 0.1, 0.3, and 0.6 V. The two low values are interesting if you want to measure components in a circuit (at 0.6 V, the measurement may be disturbed by potential diode junctions in the circuit). Finally, the LC1020E offers a bias option that is rarely found in LCR meters in this price range. This allows you to add a DC voltage of 0.5 V to the measurement signal to measure electrolytic capacitors more accurately.
 

Other features offered by the LC1020E include a hold function to temporarily freeze the data on the display and a data logging function that allows you to test how many measured components fall within a certain tolerance. Finally, there is a settings menu for language selection, screen brightness, beeper volume, automatic shutdown after a certain time, and calibration.

The LC1020E in Practice

The LC1020E starts up quickly in a few seconds, and the display is clear and well-organized. At the top the main and secondary values are shown with 4.5 digits, while at the bottom we see the selected settings for frequency, measurement voltage, bias voltage, and measurement range. At the very top are the measurement speed and battery level are visible. By default, the meter is in auto mode, in which it automatically recognizes the connected components. This usually works without problems, but sometimes it is necessary to manually select the component type and/or the measurement range. This can all be done using the settings buttons or the cursor pad, giving you two options for adjusting a setting. Furthermore, by long-pressing the OK button, you enter the settings menu, where you can immediately turn down the rather loud beeper, as it sounds with every button press.
 

Wired components can be easily measured using the included Kelvin clips, but they are not very suitable for SMDs. You can try using the included test probes, but these are not very convenient. A good solution for this is purchasing a separate SMD test tweezers equipped with banana plugs.

I measured coils, capacitors, and resistors of various values with the LC1020E and compared them to a reference LCR meter with a basic accuracy of 0.5%. Although the LC1020E has a basic accuracy of 0.3%, this applies only to a few ranges and a measurement frequency of 1 kHz. In other ranges and frequencies, it can vary by a few percent for large component values. The results were remarkable, as both meters indicated virtually the same readings with differences of at most 0.3 to 0.4%. Only with larger electrolytic capacitor values the differences were slightly larger, up to approximately 2%. During resistance measurements, the readings were even within 0.1% of each other! Kudos, those are very good results for a meter in this price range.
 

Kelvin Clips or Not?

The included Kelvin clips look decent, they clamp well, and the jaws align neatly. There is no reason not to use them. The question, however, is whether they are always necessary. Actually, Kelvin clips are mainly useful when measuring small resistance values because the four-point measurement excludes the resistance of the test leads, so only the component itself is measured. For the majority of all other measurements, you can also use a pair of test leads with sturdy banana plugs and alligator clips. That might result in a few pF extra when measuring small capacitors, but otherwise, it has little influence. With a 47 pF capacitor, the test leads indicated 4 pF more than with the Kelvin clips (moreover, this can largely be compensated for by recalibrating with the test leads connected). However, for resistance measurements below a few ohms, it is recommended to always use the Kelvin clips. In that case, my (admittedly very solid) test leads already showed a deviation of 0.05 Ohm!

Conclusion

Fnirsi is known for its affordably priced measuring equipment. This is once again evident with this LC1020E LCR meter. The device looks well-finished, has an attractive display, and comes standard with a set of Kelvin clips. Furthermore, my test measurements show that the LC1020E also delivers very accurate results. When you consider that a comparable LCR meter easily costs two or three times as much and does not include Kelvin clips, the choice is easily made. With this LC1020E, Fnirsi has delivered an excellent device at a very competitive price!