The FNIRSI DSO-TC4 is a 3-in-1 transistor tester, digital oscilloscope with 10 MHz bandwidth and 48 MSa/s, and signal generator. It features a 2.8-inch TFT display, USB Type-C power supply, built-in 1500 mAh battery, and input protection up to 400V.

The FNIRSI DSO-TC4 is a multifunctional measuring device designed for servicing, diagnosing and developing electronic circuits. It combines a digital oscilloscope, a signal generator and an automatic electronic component tester in one portable housing.

The oscilloscope provides real-time sampling at a rate of 48 MSa/s and an analog bandwidth of 10 MHz. It supports AC and DC coupling, automatic triggering, and saving screenshots for later analysis. The maximum input voltage is up to 400 V.

The component tester automatically recognizes the type and arrangement of terminals and measures the properties of transistors, diodes, MOSFETs, SCRs, resistors, capacitors and inductance. The signal generator supports 13 signal shapes with adjustable frequency, amplitude and duty cycle.

The device has a 2.8-inch color TFT screen and a built-in 1500 mAh lithium battery, which allows for up to approximately 4 hours of operation without external power.

– 3-in-1 oscilloscope, component tester and signal generator
– 10 MHz bandwidth and 48 MSa/s sampling
– Automatic identification of electronic components
– Signal generator up to 50 kHz with adjustable amplitude
– Portable design with built-in battery

Technical features:

– Brand: FNIRSI
– Model: DSO-TC4
– Device type: Digital oscilloscope, transistor tester, signal generator
– Display: 2.8-inch TFT color display
– Lighting: Adjustable brightness
– Dimensions: approximately 90 x 142 x 27.5 mm
– Weight: approximately 186 g

Power supply:
– Power connector: USB Type-C
– Input voltage: 5 V
– Current: 1 A
– Battery: Lithium, 3.7 V, 1500 mAh

Oscilloscope:
– Real-time sampling: 48 MSa/s
– Analog bandwidth: 10 MHz
– Input impedance: 1 MΩ
– Coupling mode: AC, DC
– Voltage range:
– Probe 1:1: 80 Vpp
– Probe 10:1: 800 Vpp
– Vertical sensitivity: 10 mV div to 10 V div
– Time base: 50 ns to 20 s
– Trigger modes: Auto, Normal, Single
– Trigger types: Rising edge, falling edge
– Automatic measurements: Max, Min, Avg, RMS, Vpp, frequency, period, duty cycle

Signal generator:
– Signal formats: 13 types
– Frequency range: 0 to 50 kHz
– Output amplitude: 0.1 V to 3.0 V
– Duty cycle of rectangular signal: 0 to 100%

Component testing:
– Resistors: 0.01 Ω to 50 MΩ
– Capacitors: 25 pF to 100 mF
– Inductors: 10 µH to 1000 µH
– Diodes and Zener diodes: up to 32 V
– Transistors, MOSFETs, IGBTs, SCRs
– Sensor support: DS18B20, DHT11

Package includes: 1x FNIRSI DSO-TC4, 1x High Voltage Probe P6100, 1x Power Adapter, 1x USB TypeC Charging Cable, 3x Test Hook, 1x Crocodile Clip, 1x Instructions

Warranty: 12 months

Weight: 0.250kg

Dimensions: 90 x 142 x 27.5 mm

Manufacturer:

Shenzhen FNIRSI Technology Co., Ltd.
8F, Weihuada Industrial Park C building West, Li Rong Road Da Lang Street, / Longhua District
518109 Shenzhen
China
jason@fnirsi.com

Data of the responsible person in the EU:

Tech Trade doo Trzin
Blatnica 8
1236 Trzin, Slovenia SL
info@techtrade.si

Same summary

The Fnirsi DSO-TC4 digital transistor tester, signal generator and oscilloscope proves to be an extremely useful tool for DIYers and anyone who needs quick and transparent monitoring of basic electrical values. Its digital and handheld design makes it easy to measure in a variety of locations – from the home, car to field repairs. The device makes the most sense for users who do not need advanced laboratory functions, but primarily want reliable basic testing up to 400 V. For more demanding tasks involving higher voltages or more frequent stationary use, however, the basic set of functions could limit wider usability. It is also particularly practical that it combines several functions in one device, which simplifies work and reduces the need for additional tools.

Recommendation source: Enaa guides and team experiences.

User view

This digital multimeter is often used by individuals who perform basic repairs or diagnostics on electrical wiring in their homes, garages, or cars. They are best suited for the combination of portability, ease of use, and the fact that they can quickly check transistors, signals, and basic voltages in circuits with one tool. It is also a popular choice for beginners because it is easy to use and provides a clear, numerical readout.

When making their choice, many users also highlight the trustworthy experience with the Fnirsi brand, which is considered practical and innovative in the field of digital measuring tools.

Why buy at Enaa

Enaa provides a simple comparison of similar digital and handheld multimeters, making it easier to choose based on your needs and usage. In addition, you can get additional professional support when purchasing if you have questions about the suitability of the measurement range or functionality for basic home measurements.

Answers to frequently asked questions

What types of electrical measurements is this multimeter best suited for?

The device is particularly suitable for basic voltage, resistance, continuity and transistor testing measurements, both for home repairs and basic automotive diagnostics.

Is it suitable for use in a car?

Yes, it is suitable for basic measurements in cars, such as testing the battery, alternator or checking fuses, as it supports voltages common in vehicles.

Is this tester safe to work with higher voltages?

It is important not to exceed the maximum permissible voltage of the device - the model is designed to measure up to 400 V, which is sufficient for most household and basic automotive tasks.

Can the device be used outdoors or in humid conditions?

Outdoor use is possible, but it is recommended to protect the device from direct contact with water or extreme humidity, as basic models usually do not have advanced protection against moisture ingress.

Is current measurement limited with this model?

The model is intended primarily for basic measurements, so for frequent current measurement without breaking the circuit, we recommend using a multimeter with current clamps if this is your main need.

Description updated: April 2026