DMMs make lousy oscilloscopes...

Thread Starter

Ya’akov

Joined Jan 27, 2019
5,683
But for 200mHz signals, you can see the waveform. I suppose if I were without an oscilloscope, and for some reason need to see a ~100 to 300mHz waveform, it would be better than nothing.

tempImage83YFxP.gif
 

crutschow

Joined Mar 14, 2008
29,828
How are you displaying a waveform, when the data sheet does not explicitly show that option?
Is it the "Trend" display?
 

Thread Starter

Ya’akov

Joined Jan 27, 2019
5,683
How are you displaying a waveform, when the data sheet does not explicitly show that option?
Is it the "Trend" display?
Yes, it is.

It's either a 60s rolling display or a continuous one that autoscales the time axis.

Actually really useful, for the right application.
 

Hymie

Joined Mar 30, 2018
1,081
I suspect the incorrect DC reading is an artefact of the instrument’s integration time; what is the displayed value to a signal of the same amplitude at >10Hz?

It would not surprise me if a Fluke (or similar good quality DMM) displayed a similar erroneous value for the same reason – or alternatively a fluctuating DC voltage value.
 

MisterBill2

Joined Jan 23, 2018
11,932
The Fluke "Scopemeter" that I used at one job was great for spotting noise on transducer signal lines. And it was reasonable for seeing if digital data streams were happening or not, and for spotting harmonics on mains circuits. It was really good for showing noise and ripple on DC power supply outputs.
As a lab instrument it was OK for some applications. But like all other tools one had to know when it was applicable, and when it was not.
 

Thread Starter

Ya’akov

Joined Jan 27, 2019
5,683
I suspect the incorrect DC reading is an artefact of the instrument’s integration time; what is the displayed value to a signal of the same amplitude at >10Hz?

It would not surprise me if a Fluke (or similar good quality DMM) displayed a similar erroneous value for the same reason – or alternatively a fluctuating DC voltage value.
It's not an erroneous value. The displayed value is the instantaneous one at the far right which is time 0, the left is 60s. The frequency of the sine wave is 200m(illi)Hz. That is, .2/s. It's very accurate, it has no problem making the measurement.

But, that's a very low frequency and I can just roll on my scope if I need to. It was just a curiosity. It does render other waveforms at those low frequencies as well.
 
Top