When it comes to digital multimeters, both Fluke and Klein Tools are highly respected brands. The Fluke 115 and Klein MM420 are two popular mid-range models aimed at electricians, technicians, and serious DIYers. While both meters offer True-RMS accuracy and a reliable build, they differ in design philosophy and features. Let’s compare them side by side to help you choose the right one.
📋 Overview of the Fluke 115
The Fluke 115 is part of Fluke’s compact True-RMS multimeter lineup, designed for field service and general electrical troubleshooting. Known for its simplicity and rugged reliability, it’s a go-to meter for many professionals.
Key Features:
- True-RMS for accurate readings on non-linear loads
- Voltage: up to 600V AC/DC
- Current: up to 10A
- Resistance, continuity, diode test, and capacitance
- Frequency measurement
- Large backlit display with analog bar graph
- CAT III 600V safety rating
- Compact, ergonomic design for one-handed operation
The Fluke 115 is best for general electrical work in residential, commercial, and light industrial settings.
📋 Overview of the Klein MM420
The Klein MM420 is a True-RMS auto-ranging multimeter with a wider voltage range and additional features compared to the Fluke 115. It’s designed for electricians who want more measurement versatility at a competitive price.
Key Features:
- True-RMS accuracy
- Voltage: up to 1000V AC/DC
- Current: up to 10A
- Resistance, continuity, capacitance, and diode test
- Frequency measurement up to 500 kHz
- Temperature measurement (probe included)
- Low Impedance (LoZ) mode to eliminate ghost voltages
- Backlit display with 6000 counts
- Safety rating: CAT III 1000V / CAT IV 600V
The Klein MM420 is a feature-rich multimeter, suitable for electricians working on both residential and commercial projects, including HVAC systems.
⚖️ Side-by-Side Comparison
| Feature | Fluke 115 | Klein MM420 |
|---|---|---|
| True-RMS | ✅ Yes | ✅ Yes |
| Voltage Range | Up to 600V AC/DC | Up to 1000V AC/DC |
| Current Range | Up to 10A | Up to 10A |
| Frequency Measurement | ✅ Yes | ✅ Yes (up to 500 kHz) |
| Capacitance | ✅ Yes | ✅ Yes |
| Temperature Measurement | ❌ No | ✅ Yes |
| LoZ (Low Impedance Mode) | ❌ No | ✅ Yes |
| Display Resolution | 6000 counts, bar graph | 6000 counts |
| Safety Rating | CAT III 600V | CAT III 1000V / CAT IV 600V |
| Size & Portability | Compact, one-handed | Slightly larger |
| Price Range (approx.) | $$$ (premium) | $$ (mid-range) |
👍 Pros and Cons
Fluke 115
✅ Compact and ergonomic, easy to use with one hand
✅ Excellent durability and reliability
✅ Trusted Fluke accuracy and consistency
❌ Limited to 600V
❌ No temperature or LoZ measurement
❌ More expensive than the Klein
Klein MM420
✅ Higher voltage rating (1000V)
✅ Includes temperature measurement (probe included)
✅ LoZ mode for eliminating ghost voltages
✅ More affordable than Fluke 115
❌ Slightly bulkier design
❌ Build quality and durability not as legendary as Fluke
🛠️ Which One Should You Choose?
- Choose the Fluke 115 if you want a compact, ultra-reliable, and rugged multimeter that excels in everyday electrical troubleshooting and field service. It’s ideal if brand reputation and durability matter most.
- Choose the Klein MM420 if you want a feature-rich, budget-friendly alternative with higher voltage capacity, LoZ mode, and temperature measurement, especially useful for HVAC and commercial applications.
💡 Final Thoughts
Both the Fluke 115 and Klein MM420 are excellent multimeters, but they serve slightly different audiences. The Fluke 115 is a premium, compact choice for professionals who prioritize reliability, while the Klein MM420 offers more features at a lower price, making it attractive for those who want versatility without breaking the bank.