Products > Test Equipment
DSO: How to read max. voltage specs?
Aldo22:
--- Quote from: Someone on August 30, 2024, 11:37:30 am ---
--- Quote from: Aldo22 on August 30, 2024, 11:16:34 am ---Is it possible for the manufacturer to print "300V CAT II" on the device if it only applies with the 10x probes?
--- End quote ---
Yes, you need to read the manual.
Instruments are not self documenting.
--- End quote ---
There is nothing about this in the manual, only in the information quoted above.
pdenisowski:
--- Quote from: Aldo22 on August 30, 2024, 11:58:27 am ---I simply wonder whether Hantek can be so bold as to write 300V next to connections that can only handle 30V.
--- End quote ---
Working in T&M for almost 30 years, I’ve seen plenty of questionable claims, but (so far) max input voltage hasn’t been one of them. If anything, specs for max input voltage / power are usually pretty conservative. To be an order of magnitude off seems very unlikely to me.
Aldo22:
--- Quote from: pdenisowski on August 30, 2024, 01:06:24 pm ---
--- Quote from: Aldo22 on August 30, 2024, 11:58:27 am ---I simply wonder whether Hantek can be so bold as to write 300V next to connections that can only handle 30V.
--- End quote ---
Working in T&M for almost 30 years, I’ve seen plenty of questionable claims, but (so far) max input voltage hasn’t been one of them. If anything, specs for max input voltage / power are usually pretty conservative. To be an order of magnitude off seems very unlikely to me.
--- End quote ---
I think so too, especially as it's a beginner's scope that doesn't come with a printed manual.
So all you see is 300V. Any normal person would understand this as max. input voltage, especially because other scopes are also specified with this value.
But, yes, "the proof of the pudding..." ;)
Fungus:
--- Quote from: Aldo22 on August 30, 2024, 11:58:27 am ---I simply wonder whether Hantek can be so bold as to write 300V next to connections that can only handle 30V.
--- End quote ---
I doubt it very much.
Input impedance is probably 1M Ohm so 300V isn't likely to damage it - it's less than 1mA of current.
CAT ratings include transients though. That's where the doubts are.
This is academic though. Just don't use 1x probes for this check the switch and check a lesser voltage before probing to make sure the switch isn't broken.
Also: Get some fixed x10 probes (or even x100 probes) if you regularly want to look at mains AC. Reduce that 300V to 3V.
Even better: Get a differential probe and avoid the dangers of earthing as well.
Aldo22:
--- Quote from: Fungus on August 30, 2024, 02:13:48 pm ---
--- Quote from: Aldo22 on August 30, 2024, 11:58:27 am ---I simply wonder whether Hantek can be so bold as to write 300V next to connections that can only handle 30V.
--- End quote ---
I doubt it very much.
Input impedance is probably 1M Ohm so 300V isn't likely to damage it - it's less than 1mA of current.
--- End quote ---
Thank you!
--- Quote from: Fungus on August 30, 2024, 02:13:48 pm ---CAT ratings include transients though. That's where the doubts are.
This is academic though. Just don't use 1x probes for this check the switch and check a lesser voltage before probing to make sure the switch isn't broken.
Also: Get some fixed x10 probes (or even x100 probes) if you regularly want to look at mains AC. Reduce that 300V to 3V.
Even better: Get a differential probe and avoid the dangers of earthing as well.
--- End quote ---
Thanks Fungus, but really, I'll write it in bold letters now: "I don't want to measure mains with this oscilloscope" :)
As I mentioned at the very beginning, I basically just want to know whether 60VDC directly at the input (1x, with AC coupling, so that it makes sense) will destroy my oscilloscope.
That's what it boils down to.
However, this thread is also there to discuss the sometimes confusing specifications of other devices.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version