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Fluke 115 vs Klein MM420 Multimeters: A Detailed Side-by-Side Review

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.

Fluke 115 Digital Multimeter, Measures AC/DC Voltage To 600 V & Current to 10 A, Measures Resistance, Continuity, Frequency & Capacitance, Includes Battery, Holster & 4mm PVC-Insulated Test Lead

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.

Fluke 115 Digital Multimeter, Measures AC/DC Voltage To 600 V & Current to 10 A, Measures Resistance, Continuity, Frequency & Capacitance, Includes Battery, Holster & 4mm PVC-Insulated Test Lead

Fluke 115 – Check Price on Amazon

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.

Klein Tools MM420 Digital Multimeter, Auto-Ranging TRMS Multimeter, 600V AC/DC Voltage, 10A AC/DC Current, 50 MOhms Resistance

Klein MM420 – Check Price on Amazon

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

Klein Tools MM325 Multimeter, Digital Manual-Ranging 600V AC/DC Voltage Tester, Tests Batteries, Current, Resistance, Diodes, and Continuity

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

FeatureFluke 115Klein MM420
True-RMS✅ Yes✅ Yes
Voltage RangeUp to 600V AC/DCUp to 1000V AC/DC
Current RangeUp to 10AUp to 10A
Frequency Measurement✅ Yes✅ Yes (up to 500 kHz)
Capacitance✅ Yes✅ Yes
Temperature Measurement❌ No✅ Yes
LoZ (Low Impedance Mode)❌ No✅ Yes
Display Resolution6000 counts, bar graph6000 counts
Safety RatingCAT III 600VCAT III 1000V / CAT IV 600V
Size & PortabilityCompact, one-handedSlightly larger
💳 Pricing💲 Check Price💲 Check Price

👍 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

Klein Tools MM420 Digital Multimeter, Auto-Ranging TRMS Multimeter, 600V AC/DC Voltage, 10A AC/DC Current, 50 MOhms Resistance

🛠️ 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 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.

Fluke 115 Digital Multimeter, Measures AC/DC Voltage To 600 V & Current to 10 A, Measures Resistance, Continuity, Frequency & Capacitance, Includes Battery, Holster & 4mm PVC-Insulated Test Lead