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Compare the top 7 multimeter brands. Expert reviews of Klein Tools and Fluke with specs, pros/cons. Find your perfect electrical tester.
According to the Electrical Safety Foundation International, over 30,000 non-fatal shock accidents occur annually, highlighting the critical need for reliable, safe testing equipment. Choosing the right multimeter is not just about accuracy—it’s a fundamental safety decision for any electrical work.
This review compares seven top-rated multimeters from leading brands Klein Tools and Fluke. We analyze key models based on voltage range, features, safety ratings, and intended use to help you select the ideal tool for your needs, whether you’re a DIY enthusiast or a professional electrician.
At a Glance: Top 7 Products Compared
| Product | Key Spec | Best For | Rating |
|---|---|---|---|
| Klein Tools MM325 | Manual-ranging, CAT III 600V, lead-alert | Everyday electrical testing | Value Pick |
| Klein Tools MM420 Auto | Auto-ranging TRMS, measures temp & capacitance | Professional electrical testing | Feature-Rich |
| Fluke 17B+ | Measures up to 1000V, frequency to 100kHz | Accurate electrical applications | High Accuracy |
| Fluke 15B+ | Large backlit display, CAT III 600V | DIY or professional troubleshooting | All-Rounder |
| Fluke 117/323 Kit | Multimeter & clamp meter combo, AC current to 400A | Residential/commercial electricians | Professional Kit |
| Fluke 115 | Compact True-RMS, CAT III 600V | Field technicians | Compact Pro |
| Klein Tools MM720 | CAT IV 600V, LoZ mode, up to 1000V | High-safety electrical work | Top Safety |
1. Klein Tools MM325: Durable Manual-Ranging Multimeter
Key Specifications
- Type: Manual-ranging digital multimeter
- Voltage Range: Up to 600V AC/DC
- Current: Measures up to 10A
- Safety: CAT III 600V rating with lead-alert
How It Makes Life Better
This meter simplifies everyday electrical testing with core functions like checking voltage, continuity, and batteries. The manual ranging provides direct control, while the lead-alert safety feature and CAT III rating offer crucial protection against common electrical hazards, making routine checks safer and more straightforward.
Pros & Cons
✅ Pros
- Durable construction for everyday use
- Includes important safety features (lead-alert, CAT III 600V)
- Has a backlit display for low-light conditions
❌ Cons
- Manual-ranging requires user to select correct scale
- Limited to basic measurements (no temperature, capacitance, or frequency)
2. Klein Tools MM420: Auto-Ranging TRMS Multimeter
Key Specifications
- Type: Auto-Ranging True RMS (TRMS)
- Voltage Range: Up to 600V AC/DC
- Advanced Functions: Measures temperature, capacitance, frequency
- Design: Rugged drop-resistant build
How It Makes Life Better
Auto-ranging simplifies measurements by automatically selecting the correct scale, saving time and preventing user error. The True RMS ensures accurate readings on non-linear loads, while added functions like temperature and capacitance testing expand its utility for professional diagnostics beyond basic electrical work.
Pros & Cons
✅ Pros
- Auto-ranging and True RMS for ease and accuracy
- Includes advanced measurements (temperature, capacitance, frequency)
- Rugged, drop-resistant design for job site durability
❌ Cons
- Voltage range limited to 600V (lower than some competitors)
- No mention of a specific high-level safety rating (CAT III/IV)
3. Fluke 17B+: Rugged 1000V Multimeter with Thermocouple
Key Specifications
- Voltage Range: Up to 1000V AC/DC
- Advanced Functions: Measures frequency (100kHz) & temperature (400°C)
- Safety: CAT III 600V safety rating
- Included: TL75 test leads and K-Type thermocouple
How It Makes Life Better
The higher 1000V range provides a wider safety margin for various electrical applications. Its ability to measure high frequencies and temperatures, combined with the included thermocouple, makes it a versatile tool for detailed diagnostics, from motor controls to HVAC systems, all with trusted Fluke reliability.
Pros & Cons
✅ Pros
- High voltage measurement capability (1000V)
- Includes advanced functions like frequency and high-temperature measurement
- Comes complete with test leads and a dedicated thermocouple
❌ Cons
- Safety rating (CAT III 600V) is lower than the max voltage it can measure
- No mention of auto-ranging or True RMS in the provided data
4. Fluke 15B+: 1000V Multimeter with Large Backlit Display
Key Specifications
- Voltage Range: Up to 1000V AC/DC
- Display: Large backlit display
- Functions: Measures capacitance, continuity, diode, resistance
- Included: TL75 test leads
How It Makes Life Better
This meter bridges DIY and professional use with a high 1000V range and useful capacitance testing. The large backlit display ensures readings are clear in any lighting, while the included quality test leads and CAT III safety rating provide a reliable, ready-to-use package for a wide range of troubleshooting tasks.
Pros & Cons
✅ Pros
- High voltage capability (1000V) for versatile applications
- Excellent visibility with a large, backlit display
- Includes useful function for testing capacitors
❌ Cons
- Lacks advanced measurements like temperature and frequency
- No mention of auto-ranging or True RMS in the provided data
5. Fluke 117/323 Kit: Multimeter & 400A Clamp Meter Combo
Key Specifications
- Combo Kit: Multimeter and clamp meter
- Clamp Current: AC current up to 400 A
- Technology: True RMS and Low Impedance (LoZ)
- Included: Test leads, TPAK, carrying case
How It Makes Life Better
This two-tool combo eliminates the need for separate devices, allowing you to measure high AC currents safely with the clamp and perform standard multimeter tests. The carrying case keeps everything organized, making it a complete, portable diagnostic kit ideal for complex residential and commercial troubleshooting.
Pros & Cons
✅ Pros
- Complete kit with two specialized tools (multimeter and clamp meter)
- High current measurement capability (400A AC) without breaking the circuit
- Includes useful features like True RMS, LoZ mode, and a carrying case
❌ Cons
- Clamp meter measures AC current only (no DC current mentioned)
- Specific voltage ranges and other functions for each tool not detailed
6. Fluke 115: Compact True-RMS Multimeter for Technicians
Key Specifications
- Type: Compact True-RMS digital multimeter
- Voltage Range: Up to 600V AC/DC
- Functions: Measures frequency and capacitance
- Included: Test leads, holster, battery
How It Makes Life Better
Designed for field technicians, its compact size and complete kit (with holster) make it highly portable for on-the-go repairs. True-RMS ensures accurate readings on modern electrical systems, while functions like frequency and capacitance testing provide the diagnostic depth needed for both electrical and electronic equipment.
Pros & Cons
✅ Pros
- Compact, portable design ideal for field work
- True-RMS for accurate measurements on non-linear loads
- Comes as a complete ready-to-use kit with holster
❌ Cons
- Voltage range limited to 600V
- Lacks temperature measurement function
7. Klein Tools MM720: CAT IV 1000V TRMS with LoZ Mode
Key Specifications
- Safety: CAT IV 600V safety rating
- Voltage Range: Up to 1000V AC/DC
- Features: Auto-ranging TRMS, Low Impedance (LoZ) mode
- Functions: Measures duty-cycle, temperature, frequency, capacitance
How It Makes Life Better
This meter offers maximum protection with a CAT IV rating for utility-level work. The LoZ mode prevents false readings from ghost voltage, while the high 1000V range and advanced functions like duty-cycle make it a powerhouse for complex diagnostics in demanding environments.
Pros & Cons
✅ Pros
- Highest safety rating in this review (CAT IV 600V)
- Comprehensive feature set including LoZ mode and duty-cycle
- Complete kit with carrying case, thermocouple, and batteries
❌ Cons
- Safety rating (600V) is lower than its maximum measurement capability (1000V)
- Drop-resistant, but no specific ruggedness claims beyond that
Buying Guide: How to Choose the Right Multimeter
Safety Rating (CAT)
The safety category (CAT I, II, III, IV) indicates the maximum transient voltage the meter can withstand in a specific environment. This is the most critical factor for personal safety.
Always choose a meter with a CAT rating equal to or higher than the electrical environment you’ll be working in. A higher CAT rating provides a greater safety margin.
Measurement Functions & Accuracy
Consider the specific measurements you need: basic (voltage, current, resistance, continuity) or advanced (capacitance, frequency, temperature, duty-cycle). More functions increase versatility.
For accuracy on modern electronics with non-sinusoidal waveforms, look for True-RMS (True Root Mean Square) capability. This ensures correct readings on variable-speed drives, computers, and LED lighting.
Ease of Use & Design
Auto-ranging meters automatically select the correct measurement scale, simplifying operation. Manual-ranging models require user selection but can be faster for repetitive tasks.
Practical features like a backlit display, low-impedance (LoZ) mode to avoid ghost voltage, and a rugged, drop-resistant build significantly enhance usability in real-world conditions.
Voltage Range & Accessories
Ensure the maximum voltage rating exceeds what you plan to measure. A higher range (e.g., 1000V) provides a wider safety buffer than a lower one (600V).
Check what’s included. Kits with test leads, a thermocouple, a holster, or a carrying case offer better value and immediate readiness for specific tasks.
Common Mistakes to Avoid
- Ignoring the CAT Rating: Using an under-rated meter on high-energy circuits is extremely dangerous.
- Overlooking True-RMS: Assuming all meters read AC accurately on non-linear loads can lead to diagnostic errors.
- Choosing Excessive Features: Paying for advanced functions you’ll never use adds unnecessary cost and complexity.
Who Needs What
- DIY Homeowner: A basic, durable meter with a good safety rating (CAT III) for outlets, batteries, and continuity checks is sufficient.
- Professional Electrician/Tech: Prioritize a high safety rating (CAT III/IV), True-RMS, LoZ mode, and functions relevant to your specialty (e.g., temperature, capacitance).
- Field Service Technician: Look for a compact, rugged design with a complete kit (holster, case) and the specific advanced functions needed for on-site diagnostics.
Frequently Asked Questions
What does the CAT safety rating on a multimeter mean?
The CAT (Category) rating indicates the meter’s ability to withstand voltage transients (spikes) in specific electrical environments. CAT I is for low-energy electronics, CAT II for household appliances, CAT III for building wiring and distribution panels, and CAT IV is for utility connections and service entrances. Always use a meter rated for the environment you’re working in.
What is the difference between True-RMS and a standard multimeter?
A standard multimeter calculates AC voltage and current assuming a perfect sine wave, which can be inaccurate on modern electronics. A True-RMS (Root Mean Square) meter accurately measures the “heating” value of complex, non-linear waveforms found in devices like variable-speed motors, computers, and LED drivers, providing correct readings for diagnostics.
What is a low-impedance (LoZ) mode and when should I use it?
Low-impedance mode places a low-resistance load on the circuit being tested. This is crucial for identifying and eliminating “ghost voltages”—tiny induced voltages that can give false positive readings on a high-impedance digital meter. Use LoZ mode when testing in environments with many wires, like electrical panels, to confirm the presence of real voltage.
Is auto-ranging better than manual-ranging?
Auto-ranging is generally easier for beginners and versatile for varied tasks, as the meter automatically selects the correct measurement scale. Manual-ranging can be faster for repetitive checks of the same value and prevents the meter from “hunting” for a range on noisy circuits. The best choice depends on your specific workflow and experience level.
How often should I calibrate my multimeter?
Calibration frequency depends on usage and required accuracy. For critical safety or professional work where measurements inform major decisions, annual calibration is recommended. For occasional DIY use, calibration every few years or if you suspect the meter has been damaged or is giving inconsistent readings is sufficient. Always follow manufacturer guidelines.
Can I measure AC and DC current with any multimeter?
Most multimeters can measure both AC and DC current up to 10A via the test leads, but this requires breaking the circuit. To measure higher currents (like a main service), you need a clamp meter accessory or a combo kit. Always check the meter’s specifications for its maximum current rating and whether it measures AC, DC, or both.
What basic functions should every multimeter have?
At a minimum, a reliable multimeter should measure AC/DC voltage, AC/DC current (typically up to 10A), resistance, and continuity with an audible beeper. These core functions cover the vast majority of electrical troubleshooting tasks for homeowners and professionals alike, from checking outlets and batteries to diagnosing broken wires and faulty components.