Klein CL390 vs CL800: Detailed Comparison of Clamp Meters


As an electrical engineer from Stanford University with over 7 years of experience using multimeters.

The Klein CL390 and CL800 are no ordinary clamp meters. They represent the pinnacle of technological innovation, designed to tackle the toughest electrical challenges with finesse and accuracy. These gadgets are the modern-day equivalent of a superhero’s trusty sidekick, offering invaluable insights into the complex realm of electrical currents.

But what sets these meters apart? Let’s peel back the layers and uncover the unique features that make them shine.

Get ready to witness the clash of the Klein CL390 vs CL800!

Overview of Clamp Meters

Before diving into the details of the Klein CL390 and CL800, let’s first understand what a clamp meter is. A clamp meter is a handheld device used to measure electrical current in a wire or conductor. It consists of two jaws that can be clamped around the conductor, allowing the user to measure the current flowing through it. Clamp meters are versatile tools and often come with additional features such as voltage measurement, resistance measurement, and continuity testing.

Klein CL390 Clamp Meter


  • Magnetic hanger
  • Non-contact voltage tester
  • High-visibility LCD display
  • True RMS measurement
  • Max/Min capability
  • Rel/Zero capability
  • Data Hold capability
  • Auto-power off
  • CAT III 600V safety rating

The Klein CL390 is a reliable and feature-packed clamp meter designed for professionals. It offers a wide range of measurement capabilities, including AC/DC current measurement up to 400 Amps, AC/DC voltage measurement up to 600 Volts, resistance measurement, and frequency measurement. It also features a built-in non-contact voltage (NCV) detector, which alerts the user to the presence of voltage without making direct contact.


The Klein CL390 provides accurate and reliable measurements, making it suitable for a wide range of electrical applications. Its rugged construction ensures durability and longevity, even in demanding work environments. The NCV detector adds an extra layer of safety by alerting the user to potentially hazardous voltage levels. The compact design and ergonomic grip make it comfortable to use for extended periods.

Klein CL800 Clamp Meter


  • Low Impedance (LoZ) mode
  • TRMS technology
  • Thermocouple temperature
  • Low battery indicator
  • High operating altitude
  • Wide operating temperature range
  • CAT IV 600V, CAT III 1000V

The Klein CL800 is a high-performance clamp meter designed for professional electricians and technicians. It offers advanced measurement capabilities, including AC/DC current measurement up to 600 Amps, AC/DC voltage measurement up to 1000 Volts, resistance measurement, frequency measurement, and temperature measurement. It also features a low impedance (LoZ) mode for detecting and eliminating ghost voltage.


The Klein CL800 offers enhanced measurement capabilities, allowing electricians and technicians to tackle a wide range of electrical tasks. The low impedance mode helps eliminate false readings caused by ghost voltage. The large backlit display ensures clear visibility even in dimly lit environments. The sturdy construction and ergonomic design make it suitable for heavy-duty use.

Klein CL390 Vs CL800 – Specifications

SpecificationKlein CL390Klein CL800
Current Range0-400 Amps0-600 Amps
Voltage Range0-600 Volts0-1000 Volts
Resistance Range0-40 Megaohms0-60 Megaohms
Frequency Range10Hz – 60kHz1Hz – 500kHz
Temperature Range-40° – 1832°F (-40° – 1000°C)-14° – 1000°F (-26° – 538°C)
Non-contact VoltageYesYes
True RMSYesYes
Low Impedance (LoZ)Yes
Capacitance Test4000 μF6000 μF
Display4000 Count Reverse Contrast LCD6000 Count LCD
Drop Protection6.6′ (2 m)6.6 ft. (2 m)
Weight11 oz (314 g)12.5 oz (354 g)
Safety RatingsCAT III 600VCAT IV 600V, CAT III 1000V
WarrantyLimited Lifetime WarrantyLimited Lifetime Warranty

Comparison Between Klein CL390 and CL800

Now let’s compare the Klein CL390 and CL800 clamp meters across various aspects to help you understand their differences and similarities.

Design and Build Quality

Both the CL390 and CL800 feature a rugged and durable construction that can withstand demanding work conditions. They have ergonomic grips that provide comfort and control during extended use. However, the CL800 offers a slightly larger display and additional buttons for temperature measurement.

Measurement Capabilities

The CL390 and CL800 offer similar current, voltage, resistance, and frequency measurement capabilities. However, the CL800 has a higher current range of up to 600 Amps than the CL390’s 400 Amps. Additionally, the CL800 includes temperature measurement, which can be useful for HVAC professionals and those working with electrical systems that generate heat.

Display and Interface

Both clamp meters boast easily legible displays adorned with large numbers. However, the CL800 takes it up a notch with a larger display that comes with a handy backlight, ensuring optimal visibility even in challenging lighting scenarios.

On the other hand, the CL390 flaunts a smaller Reverse Contrast display, which, while functional, may not offer the same level of visual clarity as its CL800 counterpart. Moreover, the CL800 goes above and beyond by providing additional buttons dedicated to temperature measurement and mode selection, further enhancing its versatility and user-friendliness.

Accuracy and Precision

CL390 and CL800 offer accurate and precise measurements within their specified ranges. They are designed to meet professional standards and provide reliable electrical troubleshooting and maintenance results.

Safety Features

The CL390 and CL800 are equipped with safety features to protect the user from potential hazards. They both have non-contact voltage (NCV) detectors that alert the user to voltage without direct contact. The CL800 also has a low impedance (LoZ) mode for detecting and eliminating ghost voltage, which can help prevent false readings and ensure accurate measurements.

Klein CL390 and CL800 – Which One Should You Choose?

Choosing between the Klein CL390 and CL800 ultimately depends on your specific requirements and budget. If you need a reliable and versatile clamp meter for general electrical measurements, the CL390 is a great option. It offers a wide range of features and provides accurate readings for most applications.

On the other hand, if you require advanced measurement capabilities, such as higher current range and temperature measurement, the CL800 is worth considering. It provides additional functionality to benefit electricians, HVAC technicians, and professionals working with temperature-sensitive systems.

Consider your needs, the nature of your work, and your budget when deciding. Both clamp meters are excellent choices from a reputable brand like Klein, ensuring quality and performance.


Both the Klein CL390 and CL800 are top-notch clamp meters with their unique features and benefits. They are designed to meet the requirements of professionals and DIY enthusiasts alike. By understanding the differences between these models, you can select the one that aligns with your specific needs and preferences. When deciding, consider factors such as measurement capabilities, safety features, and overall functionality.


Can the Klein CL390 and CL800 measure both AC and DC current?

Yes, both clamp meters can measure both AC and DC current.

Are the Klein CL390 and CL800 suitable for automotive applications?

Yes, these clamp meters can be used for automotive electrical measurements, such as checking current draw and voltage in vehicles.

Do the Klein CL390 and CL800 come with test leads and a carrying case?

Yes, both clamp meters come with test leads for voltage and resistance measurements. However, the carrying case may vary depending on the package or model.

Can I use the Klein CL800’s temperature measurement feature for HVAC applications?

Yes, the temperature measurement feature in the CL800 can be useful for HVAC professionals working with heating and cooling systems.

Are these clamp meters suitable for professional use?

Yes, both the Klein CL390 and CL800 are designed for professional use, providing accurate measurements and durability in demanding work environments.

Leave a Comment