I've been thinking about a bench DMM and so far the SDM3055 looks like a strong contender. Up from that might be the 3065X, or with one more step the Keithely 6500. The better voltage references in the 3065 and 6500 make them both appealing, and all the software programmability and the display capabilities make the 6500 very appealing. Kind of a matter of how much is enough in terms of accuracy and functionality.
The price on the 3055 definitely makes it attractive but I'd like to make sure it checks off all the basics, and I'm having a hard time figuring out what to expect from it on resistance measurements. In reading around I saw a couple Amazon reviews below. While they are positive on the 3055 overall these two reviews get at what I've been trying to figure out: how useful the 5 1/2 digits really are for resistance measurements (2 or 4 wire)? I'm thinking the first reviewer might have some misunderstanding (or maybe not). It sounds from the second reviewer that a resistance measurement is possible to single digit milliohms. If so it means the 3055 can read down to 1 milliohm (.001), but not 100 micro-ohms (.0001)? Is it correct that the 3055 can display 0.001 on the 200 Ohm setting and that's as low as it will go on resistance?
https://www.amazon.com/Siglent-Technologies-SDM3055-Digital-Multimeter/dp/B00QT3RTV0/ref=sr_1_1?dchild=1&keywords=siglent+3055&qid=1587515528&sr=8-1#customerReviewsattaboy
1.0 out of 5 stars Sense Terminals? Really? Why Even Bother?
Reviewed in the United States on March 3, 2020
Verified Purchase
I bought this 5-1/2 digit DVM for measuring current shunts (pcb trace). I love the screen, and the build quality is Excellent.
The one star is for hobbling the resistance measuring function, to a point where it is almost useless for precision measurement of sub-Ohm measurement. Micro amps and volts, but as for ohms, it has a Big Fail. So they go to the trouble of putting sense terminals on this unit, and in resistance, there is a Glaring Four Zeros left of the decimal point. What a waste. Nice looking Kelvin terminals .. good for down to 0.01 ohms. So I bought a 3-1/2 digit 2 ohm meter for about $100 .. that works Very well. For sure, I do recommend Siglent, and will be ordering the 3.2Gh SA, but jumping up to a 7-1/2 digit unit to get accurate sub-ohm resistance measurements is out of my range$, or needs. Maybe there is a firmware update to fix this, or a hack on EEVblog. I do Highly Recommend this unit, except for the abysmal sub-0hm resistance capability. Cheers!
PietroMoopy
5.0 out of 5 stars Excellent.
Reviewed in the United States on June 22, 2019
Verified Purchase
Great meter great price. Have had for 3 months now and there has been no drift so far. The supplied probes were terrible at first simply because they were either to rough or had a very thin layer of something that was preventing them from making solid contact, I saw some YouTubers that had this issue as well. Anyway I took 7000grit sand paper and sanded the probe leads and since then they have been working with no issues at all The meter came with the latest firmware installed and has been bang on accurate in all ranges and well within spec. I have a Keithley DMM6500 and while it is the superior meter I still love using the Siglent, it gets used everyday for work and has never given me a problem.
Edit Update:
I have had this meter for 9 months now. Its been great overall, is very well rounded and is pretty bang on accurate still. WELL within specification. Updated pictures with precision 10v and 5v references. Also what the Keithley DMM6500 and HP 3478A read.
The main drawback to the Siglent is resistance. The resistance is accurate, but the lowest range is 200 ohm, which makes single digit milli-ohm the least significant digit. In my experience it has been accurate down to a single milli-ohm, but over time that reading will become more and more unreliable and if I did not have the Keithley to verify the reading, I would not trust it at all. They really dropped the ball on that one, other then that it is a fantastic meter for the price. There has been a firmware update which is version 1.01.01.20R2 which fixed bugs/glitches and improved some UI elements. The fan is the loudest of all instruments in my lab, I do want to replace it but do not want to void warranty just yet. I mean I can still hear the SDM3055 fan when I have my de-humidifier or AC on