Fnirsi 2C53T 50 MHz two-channel Oscilloscope/Multimeter/Generator (Review)

The Fnirsi 2C53T is a compact 3-in-1 measuring instrument that combines an oscilloscope, a multimeter, and a function generator.

There seems to be no end to the constant flow of new products released by the Chinese manufacturer Fnirsi. Sometimes these are improved versions of previously released devices, and that is the case with the 2C53T reviewed here. On the outside, the device looks exactly like the 2C23T, which I examined about a year ago. That was a well-designed 3-in-1 measuring instrument that combines an oscilloscope, a multimeter, and a function generator in a compact case for a price well under 100 euros.
 

Refreshing Your Memory

As I already noted, the case remains exactly the same, with only slight changes to the labeling on some of the push buttons. For those unfamiliar with its predecessor, here are the main physical characteristics of both the 2C23T and the Fnirsi 2C53T. The unit has a fairly small case measuring 17 × 9 × 3.5 cm, featuring a 2.8-inch color LCD that provides a reasonably bright image with good contrast. The case has blue rubber-like material on the corners and feels quite sturdy. Power is supplied by a built-in 3 Ah lithium battery, which lasts for about six hours of use.

On the front, there are four banana sockets for the multimeter, and at the top of the device, there are three BNC sockets: two for the (two-channel) oscilloscope and one for the function generator. The device is operated via 15 push buttons. A USB-C connector on the side allows for charging the internal lithium battery and connecting to a PC for firmware updates and screenshot downloads.

Many Accessories Included

The 2C53T now comes in a handy storage case that also has space for the included set of multimeter test leads, two 100-MHz oscilloscope probes (the 2C23T only came with one), a BNC cable with crocodile clips for the generator, a USB-C cable, and a small manual. As with most Fnirsi devices, everything is neatly finished and well-packaged. Even the included storage case is sturdy and practically designed.
 

Differences Between the Fnirsi 2C53T and 2C23T

With the 2C53T, the specifications and capabilities of the oscilloscope function have been significantly improved and expanded. The input bandwidth has increased from 10 MHz to 50 MHz, and the sampling rate has been boosted from 50 to 250 Msamples/s. That’s exceptional for a measuring device in this price range! Additionally, the oscilloscope now includes an X-Y mode and offers eight mathematical functions to choose from. There’s also an FFT analysis, though it’s not particularly useful for a device of this type.

A so-called “Persistence” function has been added, allowing signals to “glow” for a certain period, similar to how old oscilloscopes with cathode ray tubes displayed waveforms. The number of measurement values that can be displayed on-screen has expanded to 14 per channel. Finally, all oscilloscope settings have been consolidated into a dedicated menu, making navigation much clearer.
 

Multimeter Updates

Not much has changed with the multimeter. The resolution has increased from 4 digits (9999) to 4½ digits (19999), and the display has been redesigned with a sleeker, clearer layout. Now, there is only one analog scale. The specifications and capabilities remain the same: a basic accuracy of 0.5%, the ability to measure DC and AC voltage and current, as well as resistance, capacitance, and temperature. A continuity tester and diode tester are also included.

As with most Fnirsi multimeters, the device automatically detects whether DC voltage, AC voltage, or resistance is applied to the inputs, but you can also manually switch to a specific function.

Changes to the Function Generator

Some modifications have been made to the built-in function generator. The number of available waveforms has expanded from six to 13. The output signal now has a maximum amplitude of 3 V peak-to-peak (previously 3.3 V). However, the downside is that the frequency range has been reduced to 50 kHz (compared to 1 MHz on the 2C23T). Well, you have to make trade-offs somewhere.

Getting Started with the Fnirsi 2C53T

If you’ve ever worked with a 2C23T, you’ll feel right at home with the 2C53T. Aside from a few minor details, operation remains the same. When you power on the device, a menu appears with various icons allowing you to select a measuring instrument or access the settings menu. It’s also possible to configure the 2C53T to start directly with a specific measuring instrument.
 

The oscilloscope is the most important instrument in this device, primarily due to its large bandwidth and high sampling rate. Unfortunately, the screen has not been enlarged, so it still feels quite crowded, especially when multiple measurement readings are displayed. The oscilloscope responds quickly to signal changes, and operation has been somewhat improved with the addition of a dedicated settings menu. Adjusting the time base, sensitivity, trigger level, and signal position on the screen is now clearer: pressing the Select key allows you to choose which of these parameters can be adjusted using the cursor pad keys. The selected parameters are indicated at the top of the screen.

It's difficult to determine whether the Auto-Setup function has been updated, but I did get the impression that it works slightly faster than on its predecessor. The BNC connectors at the top are still positioned very close together, which means that probes with plastic covers won’t fit. Fortunately, two compatible probes are included.

The oscilloscope’s bandwidth does indeed extend to at least 50 MHz. However, the signal amplitude increased slightly from 10 MHz to 50 MHz, which also caused a slight variation in the measured values. This is likely due to a slightly nonlinear input stage. However, once you’re aware of this, you can compensate for it accordingly.

Multimeter Performance of the Fnirsi 2C53T

Like the 2C23T, the multimeter of the Fnirsi 2C53T features auto-detection, but it does not function below 0.7 V. If needed, you can manually switch modes if you suspect the displayed value is incorrect or if a resistance value is shown instead of a voltage reading.

I find the multimeter’s display an improvement over the 2C23T, as it now includes a single analog scale above the measured value. The minimum, maximum, and average measured values are displayed at the bottom. Once again, I tested the accuracy of the multimeter across various voltage, current, resistance, and capacitance values, and the results were identical to those of the 2C23T. In fact, the accuracy is at least twice as good as the stated specifications, which is very impressive!

That said, I do question the decision to increase the number of digits, as they are not particularly necessary given the 0.5% basic accuracy. However, this could be useful for comparative measurements. The meter includes two internal fuses for the two current ranges, which can be replaced by unscrewing the housing.

Finally, it’s a bit disappointing that, as with its predecessor, the multimeter’s four input sockets are spaced slightly less than the standard 19 mm, making it incompatible with some standard accessories. Fnirsi likely would have had to make the case a bit wider to accommodate the proper spacing.
 

Although the function generator now offers more waveform options, the signal quality has not improved. The sine wave clearly appears slightly flattened at the bottom. Zooming in reveals the relatively rough steps that make up the signal, making it suitable only for general testing where signal quality is not a priority. The frequency range limitation to 50 kHz is particularly noticeable, representing a significant reduction compared to the 2C23T.

The operation of the generator remains unchanged. The frequency can still be set precisely per hertz. The maximum output voltage is now 3 V peak-to-peak under no-load conditions. The output impedance has been adjusted and is now approximately 50 Ω. However, keep in mind that the output signal is entirely positive relative to ground, as there is no output capacitor or symmetrical power supply.

Conclusion

The new Fnirsi 2C53T may cost a few euros more than its predecessor, the 2C23T, but it delivers significant improvements in the oscilloscope section. In particular, the 50-MHz bandwidth and 250-Msamples/s sampling rate are major upgrades.

Even though the multimeter remains largely unchanged and the function generator's frequency range is significantly reduced, I would still choose the 2C53T for its oscilloscope capabilities alone. Plus, at this price, you also get two oscilloscope probes and a convenient storage case—a nice bonus!