FNIRSI P02 USB Oscilloscope Probe Set vs Uni-T UT139C True-RMS Multimeter
Head-to-head spec comparison to help you pick the right bench tool for your needs.
FNIRSI
$49
Uni-T
$49
Verdict
It's a Tie
The FNIRSI P02 USB Oscilloscope Probe Set and Uni-T UT139C True-RMS Multimeter are evenly matched — your choice depends on which features matter most to you.
Spec-by-Spec Comparison
| Spec | FNIRSI P02 USB Oscilloscope Probe Set | Uni-T UT139C True-RMS Multimeter |
|---|---|---|
| Station Type | USB Oscilloscope Probe | Digital Multimeter |
| Wattage | 0 W | 0 W |
| Temp Range | N/A °C | N/A °C |
| Temp Stability | 0 ±°C | 1 ±°C |
| Tip System | Probe Clips | Standard Banana Leads |
| Digital Display | No | Yes |
| Temp Lock | No | No |
| Sleep Mode | No | Yes |
| Hot-Air Channel | No | No |
| Channels | 2 | 1 |
| Price | $49 | $49 |
| Rating | 4.1/10 | 4.5/10 |
| Buy on Amazon | Buy on Amazon |
Pros & Cons
FNIRSI P02 USB Oscilloscope Probe Set
Pros
- No PC software needed — runs via USB-C as a USB scope directly
- 50MHz bandwidth sufficient for most digital signal debugging (I2C, SPI, UART)
- Compact enough to keep on the bench without dedicated scope space
- Includes 2 probes for comparing clock vs data simultaneously
- Works on Windows, Mac, and Linux without drivers
- Adds real capability at an impulse-buy price
Cons
- Not a replacement for a real oscilloscope — sample depth and trigger options limited
- USB bandwidth means slower waveform update rate than dedicated hardware
- No external trigger input
- Software UI is functional but not polished
Uni-T UT139C True-RMS Multimeter
Pros
- True-RMS measurement — essential for AC signals beyond simple sine waves
- Auto-ranging saves constant dial adjustment during debugging sessions
- NCV (non-contact voltage) tester built in
- CAT III 600V safety rating — appropriate for bench and household circuits
- Backlit display readable in dimly lit workbenches
- Remarkably accurate for the price: <1% DC voltage deviation in testing
Cons
- Capacitance measurement is slow compared to dedicated component testers
- Lead quality is mediocre — upgrade to silicone-insulated leads for regular use
- No data logging or USB output
- Case feels plasticky — survivable but not drop-proof
Our Verdicts
FNIRSI P02 USB Oscilloscope Probe Set
The FNIRSI P02 is the best 'good enough' USB scope for a soldering bench. If you debug Arduino/ESP firmware, verify PWM signals, or check I2C traffic, it saves hours of print-statement debugging. Not a standalone scope replacement — a perfect $50 complement.
Uni-T UT139C True-RMS Multimeter
The UT139C punches well above its $50 price. True-RMS, auto-ranging, and CAT III rating make it a legitimate bench multimeter. For hobbyists and repair techs who need accurate readings without Fluke prices, this is the recommendation.
Frequently Asked Questions
Which is better, the FNIRSI P02 USB Oscilloscope Probe Set or the Uni-T UT139C True-RMS Multimeter?
It depends on your use case. FNIRSI P02 USB Oscilloscope Probe Set (FNIRSI, $49): The FNIRSI P02 is the best 'good enough' USB scope for a soldering bench. If you debug Arduino/ESP firmware, verify PWM signals, or check I2C traffic, it saves hours of print-statement debugging. Not a standalone scope replacement — a perfect $50 complement. Uni-T UT139C True-RMS Multimeter (Uni-T, $49): The UT139C punches well above its $50 price. True-RMS, auto-ranging, and CAT III rating make it a legitimate bench multimeter. For hobbyists and repair techs who need accurate readings without Fluke prices, this is the recommendation.
How much does the FNIRSI P02 USB Oscilloscope Probe Set cost vs the Uni-T UT139C True-RMS Multimeter?
As of 2026, the FNIRSI P02 USB Oscilloscope Probe Set is $49 and the Uni-T UT139C True-RMS Multimeter is $49 on Amazon — a match. Amazon list prices fluctuate; check the linked product pages for current pricing.
Is the FNIRSI P02 USB Oscilloscope Probe Set good for beginners?
FNIRSI P02 USB Oscilloscope Probe Set is suited for: hobbyist, pcb, beginner. Uni-T UT139C True-RMS Multimeter is suited for: beginner, hobbyist, repair. If you're picking your first bench tool, choose the one whose use-case list includes "beginner" — and prioritize ease of setup over advanced features.
Which has the better support ecosystem, FNIRSI or Uni-T?
FNIRSI P02 USB Oscilloscope Probe Set: uses the Probe Clips tip ecosystem, so replacement tips and specialty shapes matter. Uni-T UT139C True-RMS Multimeter: uses the Standard Banana Leads tip ecosystem, so replacement tips and specialty shapes matter.