Multimeter safety

Safety must always remain priority number one when doing measurements with multimeters. Working safely, while making electrical measurements, is not rocket science. It’s a simple combination of careful planning, safe practices and using the right tools in the right way. The more voltage and current is present in the circuit, more careful you have to be. Fluke Safety video gives some overview on the multimeter measurements safety around power circuits.

Stock Multimeter Explosion shows one worst case scenario what can happen when you make mistakes with multimeter and high power energy source. This video illustrates why fused leads should be used with multi-meters. If you plug the leads in the wrong spot or have the wrong settings this is what happens. This video illustrates why fused leads should be used with multi-meters when measuring power circuits.

Check also High Energy Multimeter Destruction video for more examples of exploding multimeters and damages inside multimeters.


  1. Fused multimeter probes « Tomi Engdahl’s ePanorama blog says:

    [...] lethal voltages and short circuit current. Multimeter have fuses inside them, but those fuses do not always provide enough protection. Stock Multimeter Explosion video illustrates what happens when the fuse inside multimeter is not [...]

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    • Tomi Engdahl says:

      I have earlier used method in-house development + developer.
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  7. says:

    Write more, thats all I have to say. Literally, it seems as though
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  8. Tomi Engdahl says:

    10 Multimeter Makers With Models Under $150

    The handheld DMM (digital multimeter) is a tool that every engineer and technician needs. You probably have at least one on your bench or toolbox, whether at work or at home. At home, you’re likely to use a DMM on a home electronics project or to diagnose problems on your car, electrical wiring, or perhaps a kitchen appliance.

    Handheld meters are available online, through electronics distributors, local electronics stores, electrical supply stores, hardware stores, flea markets, Radio Shack (the few that remain), and on eBay. Here is a sampling of the meters you might find for under $150.

  9. Tomi Engdahl says:

    Multimeter Safety and Input Protection

    Electricity is a silent killer. You can’t see, hear or smell it, but it will bite if given the chance. While those working in offices and labs are in generally safe environments largely shielded from hazardous electricity, engineers, electricians and linemen are often directly exposed. They are at greater risk from electrical hazards and should get the best made device they can.

    If you intend to measure mains circuits, safety should be paramount in choosing the right meter. Just because a multimeter touts a high category rating and looks tough from the outside, and can measure nominal mains current without issue, doesn’t mean it can protect you in the event of a voltage spike.

    CAT-II: single phase circuits, for equipment connected to socket outlets, such as appliances and power tools. For testing the socket itself, you would want a CATIII meter.

    CAT-III: up to three phase systems and including single phase circuitry of installations; that is, beyond the socket and cord. Includes distribution boards, three phase outlets and commercial lighting.

    CAT-IV: where spike levels can be high, such as at a building’s source power; includes measurements of supply meters, main panel boards and outdoor conductors.

    Fuses: offer a basic level of protection and are typically not quick enough to protect a multimeter from transient exposure without the addition of further protection. They protect from excessive current, with High Rupture Capacity (HRC) type fuses providing the surest protection.

    Advanced Protection

    Along with HRC fuses, CATII-rated multimeters and up should also have a number of other components built in to protect from voltage spikes. These include power resistors, positive temperature coefficient (PTC) resistors (known as thermistors), zener diodes, and metal oxide varistors (MOVs). Brand, as much as price, may dictate whether or not these essential electronic components have been incorporated.

    Probes: good test leads are often overlooked but are equally important, since they are the point of contact with live conductors. They should have finger guards and shrouded jack plugs, and should be certified to the same category as the meter, if not higher.

    Along with good mechanical properties, input protection is the most important factor in selecting a safe multimeter.

  10. Tomi Engdahl says:

    ET201 Oscilloscope-Multimeter comes with a lot of surprises

    The EONE ET201 is one of the most affordable tools to visualize waveforms. It is also a decent multimeter and a safety hazard. In this video I am showing all pros and cons I could find about the scopemeter.

    costs 55$, has an oscilloscope (sorta) but it isn’t auto ranging? what a strange multimeter
    And they say that Germans can’t be funny!…ever!

    I really wish the Chinese would stop lying on the ratings like that. Anyone who actually needs a CAT IV is never going to believe it, and anyone who would believe it is never going to be near a circuit that needs it. If they’d just make an honest CAT II meter, which isn’t hard, everyone would be happy.

    “The manufacturer can circumvent my biggest complaint”
    This is a very very good point!
    Manufacturers have no idea what we want.
    Most of us would be fine with a 250v or lesser meter using glass fuses as long as it doesnt make bullshit claims!
    When they do make the big claims though they are obligated to back them in the product.


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