Do not attempt to measure live power directly.

[pmk2015]

Hi

Please can someone explain this. In the manual it states Do not attempt to measure live power directly.

Is this scope suitable for measuring voltage ripple on power supplies upto 12v DC? Does the above mean you can not connect it accross the + and - of the power supply?

Sorry if this is a dumb question.

Thanks

[jye1]

Live power usually means power directly from wall socket. It has voltage around 110V or 220V. For 12V DC power supply you can use the scope to measure directly without problem.

[staceygeek]

Why can't I measure main power directly? I think I can, just need a probe with x10 attenuator and have the oscilloscope poewered from internal battery for safety. What's the problem to measure it then?

[jye1]

Why can't I measure main power directly? I think I can, just need a probe with x10 attenuator and have the oscilloscope poewered from internal battery for safety. What's the problem to measure it then?

Technically with proper attenuator the scope can measure main power directly. But there is a HUGE safety concern for so doing because there is no proper isolation between the scope and the main power. Even battery is used to make the scope floating but your body may not and the device does not have the right design for high voltages. It is still very risky. We absolutely do not recommend users to use the scope to directly measure live power. If you really need to do you have to make good isolation to ensure safety. For example, if you want to measure voltage use a small transform which can reduce voltage to the range of the scope. Connect its primary to main power and measure at the secondary. If you want to measure current use a current sensor.

[staceygeek]

jye1, thanks for your precautions, but you are like all the others from the world of capitalism ... obsessed by safety.

https://www.youtube.com/watch?v=zaaXpedYoqI

start watching at 20:10 and you will see, it works fine. As I already mentioned, behind x10 probe there are only 22V that reach the input - quite within the range of the scope. So all in all, it goes down to the quality of probe isolation. But I would really recommend to rely on internal battery while doing such measuring, just to prevent any possibility of making a galvanic connection between the main and the power circuit of the scope.