Klein mm400 Review 2020

Klein mm400 Reviews

Multimeters had changed a lot from when they were first discovered. The first multimeters were hard to read as they were analog. In the past, only experts could use and read the results. Digital multimeters have made reading of the results to be easy and quick.
Since there are lots of multimeter brands to choose from, it is crucial to know which brands offer reliable multimeters and which ones don’t. Klein is one of the most reliable multimeter brands and well-known for their affordable price. This is an American brand that was established in 1857. It offers some of the most durable, accurate and safe multimeters on the market. In this Klein mm400 review, we are going to discuss the Klein mm400 multimeter.
This is the perfect digital multimeter for beginners, DIY enthusiasts, and professional electricians. Read on…

Klein mm400 review(Video):

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The mm400 digital multimeter is sturdily built and has auto-ranging. In addition, the device meets the CAT III 600V safety rating. It has a battery level indicator that warns the user when the batteries become low. The multimeter is very easy to use with well-labeled buttons and an easy to turn the knob. To use the device, insert 2 x AAA batteries in the easily accessible battery compartment and carry out different tests. It measures current, voltage, resistance, temperature, capacitance, continuity, test-diodes, duty-cycle, and frequency.

Related: Digital Clamp Multimeter Klein CL800 Review

Technical Features Of The Klein mm400 Multimeter


Klein mm400

Display: 3 ¾ digit, 4000 Count LCD
Storage temperature: 14°F to 140°F (-10°C to 60°C)
Diode test: 1.5 mA max, open circuit voltage 3.0V DC
Continuity Check:Audible signal <50Ω
Sampling Frequency:3 samples per second
Overload: “OL” indicated on display, overload protection 600V RMS in all settings
Polarity::“-” on display indicates negative polarity
DC volts: Ranges: 400.0mV, 4.000V, 40.00V, 400.0V, 600V
Resolution: 0.1mV, 1mV, 10mV, 100mV, 1V
Accuracy: ±(1.0% + 8 digits), ±(1.2% + 3 digits), ±(1.5% + 3 digits)
Input impedance: 10MΩ
Overload protection: 500mA / 600V and 10A / 600V Fuses
Frequency Range: 50 to 60Hz
AC volts: Ranges: 4.000V, 40.00V, 400.0V, 600V
Resolution: 1mV, 10mV, 100mV, 1V
Accuracy: ±(1.2% + 5 digits),
±(1.5% + 5 digits),
±(2.0% + 5 digits),
±(1.0% + 8 digits),
±(1.2% + 3 digits),
±(1.5% + 3 digits)
Input impedance: 10MΩ
Overload protection: 500mA / 600V and 10A / 600V Fuses
Frequency Range: 50 to 60Hz
Price: buy mm400 klein toolCheck Price

Product description of mm400 multimeter

  • Powered by 2 x AAA batteries
  • Durable plastic body
  • Auto-ranging multimeter
  • CAT III 600V and CAT IV safety rating
  • Low battery level indicator
  • Measures volts, ohms, temperature, capacitance, frequency, test diodes, continuity, etc.
  • Large bright backlight display
  • Buttons, dials, and ports

Benefits of using Klein tools mm400

Sturdy construction

The Klein mm400 multimeter is a reliable multimeter and suitable for construction sites or any tough surroundings. The gadget is made of a sturdy plastic body which can resist an impact of up to 1 meter when dropped accidentally.
klein tools mm400 reviewCheck Price

Whether you are an electrician or DIY enthusiast, this device will serve you for over a long period of time. It can get crushed or fall accidentally but it will still deliver accurate readings.

Safe to use

One of the features that separate Klein multimeters from other brands is that they are safe to use. The Klein mm400 digital multimeter is safe to use with its ratings of CAT III 600V and CAT IV. This prevents the device from harming you. Thus, you can use it knowing that it is safe.

Compact design

The wonderful design of the multimeter helps the user to have an easy time carrying out different tests and measurements. It fits perfectly in the hand of the user and it can be easily kept in a backpack. Also, it has a molded-in tests, lead holders. With its compact design, you can be certain that it will fit well in tight places.

Easy to use

If you have been having a difficult time using advanced DMM, this is not the case with the Klein mm400 multimeter. The auto-ranging multimeter has a simple to use interface. The buttons and dials are clearly indicated and very easy to use. Also, the ports have clear signs for easy insertion of test leads. In addition, it has a large backlight display screen for showing results from tests conducted in a lit place or in a dark area.

Comfortable and easy to handle

Another great attribute about the Klein mm400 multimeter is that it is easy to handle and very comfortable.
Auto Ranging Digital Multimeter mm400Check Price

You don’t need to hold it with two hands as just one is enough. Also, it has a nice design that fits well in the palm of your hands. This makes testing, troubleshooting, and reading to be easy.

Low-level battery indicator

The mm400 digital multimeter is powered by 2 x AAA batteries. These are included in the purchase. Also, it has a low-level battery indicator that assists the user to check the battery percentage. This will help you to be ready with spare batteries in case they run out during use.

Great price

Despite having outstanding features and carrying out accurate readings, this multimeter is offered at a great price. So, this is a great bargain for those who want a reliable and durable digital multimeter for long-term use.

Setbacks of Klein mm400

  • It doesn’t provide accurate readings every time it is used. So, you have to be patient and try several times.

Klein mm400 vs mm600

Difference between mm400 and mm600.




Batteries: 2 AAA batteries required. 2 AAA batteries required. (included)
Voltage AC/DC: 600 volts 1000 volts
Ohms(Resistance): 40 MΩ 40 MΩ
Capacitance: 40nF – 200µF 40.00 nF – 4000uF
Frequency: 10Hz – 50kHz 1Hz – 50 KHz
Current AC/DC: 10 A 10 A
Battery Cell Type: Alkaline Alkaline
Batteries Included?: No Yes
Type & volts: Digital Multimeter, Auto-Ranging, 600V Digital Multimeter, Auto-Ranging, 1000V
Size: Auto Ranging/Temp, Cap, Freq Standard
Item Weight: 10.6 ounces 10.6 ounces
Product Dimensions: 1.8 x 3.1 x 6 inches 10 x 5.6 x 2.7 inches
Review: Detail Reviews link Klein mm600 review
Price: Auto Ranging Klein multimeterCheck Price Check Price

Final thoughts
The Klein mm400 digital multimeter is a sturdy device that is ideal for engineers, DIYers, and electricians. The DMM has the ability to perform a wide range of tests such as voltage, current, resistance, frequency, continuity, test diodes, temperature, capacitance, and duty-cycle. The device can defy impact up to 1 meter and has a safety rating of CAT III 600V. When the battery becomes low, the battery level indicator will alert you by showing the battery level. This is an amazing multimeter for startup electricians and engineers. I hope this Klein mm400 review will has given clear idea about this multimeter. Comment below if you have any question about this mm400 multimeter.

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