FNIRSI P02 USB Oscilloscope Probe Set vs Uni-T UT139C True-RMS Multimeter
Head-to-head spec comparison to help you pick the right station 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.