Siglent SDM30xx and Rigol DM30xx share some guts? - Page 1
Forum section: electronics / testgear

author: eevacc
author_rank: Newbie
timestamp: September 28, 2023, 08:41:55 pm
content: Hi!I'm making a "chinese corner" inside my serious lab just for FUN (and stupidity) and am currently choosing between the DMMs Siglent SDM3055 and Rigol DM3058E.A quick look into the spec sheets revealed theexactsame accuracy data (see pictures attached). Also many other wordings in those spec sheets are exactly the same (example "NMRR: 20 dB are added if open the AC filter").This made me think for a moment. It's not random, obviously these are based on some common platform, either Siglent buys it from Rigol or vice versa, or they both buy it from someone else.Looking at the guts of SDM3055 and DM3068 (see pictures attached, couldn't find those of DM3058), clearly there are many similarities.I haven't found any information on this, does anyone have an insight?I don't want to throw money around, just some OK precision for the best price possible. Unfortunately I prefer the Siglent (bigger display, better toy!!) which currently costs about 85 Euro more.The SDM3045X ist just a bit too inaccurate, for about 20% (80 Euro) more I can get the DM3058E already which has 0.015% DCV accuracy instead of 0.06%, quite a big difference (even a toy has to have some accuracy, otherwise I will make it explode somehow!).The additional 85 Euro on top would be just for the nicer display of the Siglent. Is it worth it...? Thinking.Thanks!

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 28, 2023, 10:08:59 pm
content: I have both the SDM3045X, and SDM3055. My SDM3045X is upgraded to the SDM3055X-E (China market model, same hardware as 3045X, but 5.5 digits).You can see a comparison I made in the 3045X improvement thread:https://www.eevblog.com/forum/testgear/sdm3045x-to-sdm3055x-e-improvement-thread/msg5075287/#msg5075287Both meters are great, and my X-E version is more stable as it's had more break-in time.

author: Njk
author_rank: Frequent Contributor
timestamp: September 28, 2023, 10:58:11 pm
content: Which DMM is less susceptible to internal rust development? Early here were a complains about rusty chassis in some Siglent instruments. That suggests that the chassis is made of bare steel sheet, with little or no electrochemical plating. Is that still true? Hard to find out on the internet images.

author: tautech
author_rank: Super Contributor
timestamp: September 28, 2023, 11:00:57 pm
content: Quote from: Njk on September 28, 2023, 10:58:11 pmNo.Rust issues long ago arose from chassis suppliers using poorly coated sheet stock.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 29, 2023, 12:36:55 am
content: Dave used to complain a lot about the "siglent rust". And all I ever saw on his video's were very tiny specks of rust on the sides of cut steel sheet. And those sheets are plated before being cut, so there is no zinc plating on the cuts at all. I find it hard to believe there ever was any serious issue with rust in Siglent equipment.

author: thm_w
author_rank: Super Contributor
timestamp: September 29, 2023, 12:45:26 am
content: I don't know about the release dates, I think both SDM3055 and DM3068 were around 2011 time frame?There was also the Rigol DM3064 which predates the DM3068, ~2009. Probably internally very similar.Its not unusual to see specs copied from other manufacturers. The baseline has been set, they know it can be done at a certain pricepoint, so the spec is their goal to create a competing unit. My guess here is a Siglent engineer bought the competitions unit and did their own design, heavily inspired. I'm sure the rigol unit was inspired as well, though I don't know from what. Don't really care either way TBH.Quote from: Doctorandus_P on September 29, 2023, 12:36:55 amIts more of an ongoing joke if anything. Howthey respondeddid not help.The concern IMO, was that the rust happened AFTER assembly, so could affect components as well. But once it is confirmed to be pre-existing rust it is basically a non-issue.

author: tautech
author_rank: Super Contributor
timestamp: September 29, 2023, 12:52:31 am
content: Quote from: thm_w on September 29, 2023, 12:45:26 am3055 release was late 2014 or early 2015.I started the SDM3055 thread September 19, 2014 and later added SDM3045X & 3065X (2016 & 2017) into the same thread.https://www.eevblog.com/forum/testgear/siglent-new-bench-dmm-sdm3055/

author: Njk
author_rank: Frequent Contributor
timestamp: September 29, 2023, 01:15:39 pm
content: Quote from: Doctorandus_P on September 29, 2023, 12:36:55 amI was a frequent visitor to the scrap bins at manufacturing plants. It's a free source of many interesting materials which are virtually impossible to obtain in any other way. So I know what happens to a properly plated steel parts after a months in open air. The rust does not start until the plating in that area completely turned to a whitish substance.This is something different. The very purpose of plating is to prevent corrosion, not to provoke it. Fake plating just should not be there because rust is a thing which is very difficult to remove. Similar to a stain on the reputation.

author: klausES
author_rank: Regular Contributor
timestamp: October 01, 2023, 01:55:33 pm
content: The cut edge grate and the rust stains should have been history long ago.My Siglent devices are no longer completely new, but none of them had the problem. So it has to be several years ago.For long -term, it always depends on the factors such as air humidity in the rooms, where a device spends its life.Even in an apparently dry room on the ground or near a damp wall, it can rust more than freely on a closet or table.

author: shakalnokturn
author_rank: Super Contributor
timestamp: October 11, 2023, 05:10:15 pm
content: To moderators:How did memeber "eevacc" get banned in just one post?I'm assuming it's for private messages as I've received a recent request for help from him, I don't know if it's legitimate or if there's a catch, anyway I can't answer him due to the ban.I'd be interested to know if there was a complaint of someone actually being ripped-off by him leading to the ban?

author: KungFuJosh
author_rank: Super Contributor
timestamp: October 11, 2023, 06:50:56 pm
content: Quote from: shakalnokturn on October 11, 2023, 05:10:15 pmI'm not a mod, but he doesn't appear banned to me?:https://www.eevblog.com/forum/profile/?u=965881

author: thm_w
author_rank: Super Contributor
timestamp: October 11, 2023, 11:07:10 pm
content: Quote from: KungFuJosh on October 11, 2023, 06:50:56 pmLook at the image under their name, its the banned imageCould be the troll who keeps trying to come back.

author: KungFuJosh
author_rank: Super Contributor
timestamp: October 12, 2023, 12:15:48 am
content: Quote from: thm_w on October 11, 2023, 11:07:10 pmOh, weird. For him to be "the troll" he must be pretty bad. There's a few trolls around here. 😉