Oscilloscope Safety - How to use your scope safely!

This is a very condensed version of a video by EEVblog (and others) about potential safety problems from oscilloscopes. To view a more comprehensive video, look over to EEVblog's "How not to blow up your oscilloscope" video.

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[gerhardwessels]

A suggestion that may be helpful: Put some green heat shrink on the scopes earth ground leads - it will constantly remind you it is an earth conductor and not just another test lead as in the case with multi-meters

[PatrickHoodDaniel]

I've watched so many similar videos, but it didn't really hit until I watched this one! I understood this because you are showing the continuity between all of the BNC connectors and the ground clip. Thank you for making this clear!

[BjornV]

i know this is a older video, but everybody on YouTube who makes video's about Oscilloscope Safety and measuring mains voltage, left one part out of the video.
If you simple want to see the 50 or 60Hz sine wave of your mains outlet, you don't need to connect the ground lead of your scope probe.
Your mains is ground referenced, but also the tip of your scope probe is ground referenced, so you don't need to connect the ground lead,
and for extra safety, you can best removed your ground lead from your probe, that way this lead can't accidently touch something.
Simple set your scope probe at X10 setting, and only use the tip of the probe and you can touch Hot / Line / Phase / Neutral without risk.
If you want to do measurings in a circuit or device that is powered from mains, and you want measure across components in circuit, or circuits that use higher frequency then 50 or 60Hz, you will get more noise when the ground lead of the probe is not used, and this method of only using the probe tip cannot be used.

[literaturaeproposito]

Thank you so much! There are very few sources of information so clear and so well explained as your video. So many people adopts measures that risk security, as it is the case of neutralizing the grounding of the oscilloscope to make measurements.

[cookieboi]

Thank you for a comprehensive video on this subject. I have seen EEVblog' s video on this subject, but he doesn't show the use a RCD/GFCI gadget, at least not on any video I have seen of his. I have seen dozens of videos on scopes, but they never showed the use of a GFCI in USA, RCD in Aus and Europe. I personally have 22 circuits and all of these have RCD's on them. They are compulsory in all new homes in Australia, , , and one cannot sell / transfer an old house without having this gadget installed.

[MrJruta]

Thank you. This is EXACTLY the info I’ve been looking for!

[WireWeHere]

7:31 In household electric systems the direct connection between the neutral and ground is only done once in the first breaker panel and must not be done again in additional sub panels. If a sub panel is being added to a home it may already have a bonding screw between neutral and ground and this bonding screw must be removed for sub panel usage of a breaker panel.
Just a little detail from renovations that occasionally gets missed.

[DavidMulligan]

Thank you. "Oscilloscopes are not multimeters!" is the perfect way to phrase this message. Although I have never conflated the two tools, thinking of it this context will prevent me from making dumb errors in judgement.

[robertbatista]

That last tip about the GFCI was great. The safest way to go IF you must introduce isolation is not the cheater plug, but the isolation transformer. Then of course the professional/expensive route is the differential probe.

[yutubl]

Always check power line (outisde or inside devices) before contacting a oscilloscopes probe tip connectors: Always be sure where is the hot phase line where is ground line of power AC outlets / cables line also inside any opened device to be repaired.
Better measure again if unsure about it or forgotten, before risking to make any bad contact.

[jimhenderson]

The black leads (on scope and multimeter ) both have something in common. They both serve as a reference for the purpose of measuring voltage.
However the reference lead on the scope is a grounded reference lead on mains powered oscilloscope plugged into 3 prong wall socket vs a non - grounded reference lead on battery powered multimeter.

[FZs]

0:56 "The multimeter probes have a high resistance between each other" -- This is *only* true if the meter is set to voltmeter mode. *The ammeter mode will short the leads to each other!*

[HowardJohnstone]

It would be most helpful if you could show what you can do about this.
In the olden days, one used isolation transformers, differential input Scopes made for line voltage use etc. Today many cheap scopes have low voltage psu, such as USB power via powerpack.

[calholli]

Even if you did do that -- it would just flip the breaker in the house panel. But I get your point: be cautious where you put the ground leads.

[markarca]

Early cardiac monitors are connected to an oscilloscope (to display the ECG waveform).

[SimonBauer]

i have an owon vds1022i usb scope, i can probe whatever, its isolated. and if i dont plug my laptop in its double safe. but the bncs are still shorted together. so thats the only worry. my oscilloscope is a multimeter pretty much (ignoring voltage ratings)

[Martinko_Pcik]

It would be nice to explain if the situation changes with battery operated oscilloscopes.

[Jonathan-exsl]

Wish I watched this before I burned up my power supply 😢
Thanks for the education!!

[Anthony_Matabaro_D_]

Hi @Engineering Technology for Healthcare, I have just found this video and your channel, you have condensed the information nicely (I have subscribed). Could please inform us of what BMET is / stands for, I have searched the web but can only find references to Bermingham University or a blood test? Thank you and have a good day.

[robertsmith]

I had never thought about it before, and unless I find a scope at an estate sale it won't be an issue.
Are the digital inputs using the same ground?