graphing multi meters - Page 1
Forum section: electronics / testgear

author: R_G_B_
author_rank: Frequent Contributor
timestamp: November 26, 2017, 11:43:25 am
content: Not seen much talk about graphing multi meters on this forum.I have found them very useful compared to digital multi meter.being able to graph ohms, voltage, current, duty cycle, frequency, pulse width, power, is very useful.Be interesting to here David Jones has to say about this or maybe he could do a video on this.I own i mt2400 graphing multi meter its intended for the automotive market but its more than just an automotive graphing multimeter as its able to graph just about anything which is very useful for fault finding electrical and mechanical systems.I have a fluke 125 this can graph but graphing interval is just 15 sec per division unlike mt2400 which can graph down to 500us per division.The fluke 867b has a high resolution its good for graphing long term trends at 30,0000 counts.interesting if anyone else finds them useful

author: HalFET
author_rank: Frequent Contributor
timestamp: November 26, 2017, 01:15:47 pm
content: At what point does a multimeter turn into an oscilloscope you must ask though? You might have more luck comparing these things with the portable scopes from Fluke. But I just use my Keysight with the Bluetooth logging module for these things, the sample rate is quite good.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: November 26, 2017, 01:44:57 pm
content: Don't know about your needs, but most bench meters can output their data through GPIB/USB/LAN/... and then you can graph it in your package of choice (going from free stuff like libreoffice to stuff like Matlab). Most of them also allow you to trade in sample time for resolution and noise (I think the Keithley DMM7510 goes to 1 milion updates per second in a 3.5 digit mode. That is like having a 12-bit oscilloscope!).

author: bd139
author_rank: Super Contributor
timestamp: November 26, 2017, 02:09:59 pm
content: Agreed. I don't think a graphing multimeter is that useful on it's own because on board analysis is limited. However your bog standard hand held and bench meters with a decent SCPI interface are invaluable. I use an Agilent U1241C (10,000 count) with the USB-IR interface and GW Instek GDM8341 (50,000 count) for this. They're pretty good.To test the automation libraries I have written (python), with the above two for example, and a DG1022Z, I built a curve tracer! You can use the DC offset control on the DG1022Z to act as a relatively good SCPI controlled +/-5v programmable power supply, then measure I and V for the DUT as you sweep it.This all pops out into matplotlib:So many uses I can think of. Generic tools with programmability are the best!

author: joeqsmith
author_rank: Super Contributor
timestamp: November 26, 2017, 03:06:40 pm
content: I have a UNI-T UT181A that can graph. I have never had a case where I thought it would be helpful at home or otherwise. Normally, if I am logging data I am using a PC to collect it. It is rare that I just need one type of data so normally I will have various bits of equipment monitoring (and stimulating) the device I am wanting to look at. I also normally want all that data synchronized and I want it live. For the price of the UT181A, I suspect I could find a decent name brand bench meter and PC interface.

author: saturation
author_rank: Super Contributor
timestamp: November 26, 2017, 04:50:09 pm
content: You can perform many graphing multimeter functions with a suitably configured DSO but its requires setup and added equipment compared to a OTS Fluke 287 that is also robust enough to take to the field. But the trade off is DMM size, weight compared to a DMM without such a function. You can also get a 'hybrid' ,a Keysight meter with bluetooth dongle or a Mooshimeter, so long as the sample rate of these DMMs are fast enough for what you intend to capture, and let your smartphone, tablet or PC do the storage and analysis.