Can my DMM measure ripple?

Jump to Latest
#61
This is a capacitor bank for a 150 kV three-phase system that I happened to pass by earlier this month. The note on the fence says that it is unlocked automatically ten minutes after grounding the capacitors.

20220403_125909.jpg
 
  • Like
Reactions: Grarea
#63
jean-paul said:
Since I once worked in a job where mistakes cost a lot of money I got to know “voltage only” DMM’s. The well known mistake that OP made (we practically all have done it at least once) could then not be made. Measuring current was only allowed with clamp type meters.

Grarea, all the true RMS Fluke DMMs I owned the last 20 years or so measured ripple. FWIW I work with expensive Fluke DMMs on a daily basis but like my own 117 most of all. Affordable and can take abuse. It really pays off to buy good stuff at once.
Click to expand...
You know what? That seems a pretty good idea.
The clamp type meter idea. I didn't know that was a thing.
I imagine the cheap ones are good enough for what I want.
Less likely to fry my dmm and pretty usable. Nice to not have to break the circuit.

I have had a little look and see that you need to make sure you get an AC and DC one.

(yes, I am still sulking)
 
#64
Cheap ones are pretty accurate: Chinese know how to use crap material in a clever and effective way - don't underestimate them- however, they cut the the cost down to the barebone, which is problematic in some instances, and some upgrading can do marvels on cheap Aldi or Lidl sold devices.
I have done it, and it works OK. Everything that is required is basically present, you just need some dressing up, at least if you operate at a single frequency (50Hz in my case).
The basic ranges of the original instrument were much too hgh for my tastes, but he adapted version was perfectly usable
 
  • Like
Reactions: Grarea
#67
When I did measure the AC on the DC before I fried it, all three came in similar.
(Not sure I'm remembering the scale right)
My salas l-adapter, a nineties linear PSU and a RPi official supply all came in between 8-10mv.
I was Wondering if something else was limiting it. As in the cables or the dmm itself.

I should change the thread to 'what dmm is good for measuring ripple?'
 
#68
I picked up a cheap (second hand) AC/DC clamp meter.
I like the idea of a current only meter.
While I decide what to get/save up for with a new multi-meter/oscilloscope.
I know an oscilloscope is better, but it will be nice to be able to measure ripple in situ.
It won't be for a while though I suspect.
 
You must log in or register to reply here.
Top Bottom