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Products => Test Equipment => Topic started by: Hugoneus on July 20, 2015, 01:53:47 pm

Title: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Hugoneus on July 20, 2015, 01:53:47 pm
In this episode Shahriar reviews the Siglent SDM3055A 5.5-Digit Multimeter. After a brief look at the instrument’s datasheet, a full teardown is presented. The instrument utilizes a two-board design and a large LCD screen. The SDM3055A provides a comprehensive set of measurements including capacitance as well as various graphing capabilities including histogram, trend and bar graphs. USB and LAN connections are standard and a USB-GPIB can also be purchased. The performance of the instrument is verified through experiments with various functions and setups.

Watch the video here: [1 Hour]
youtu.be/rmTP-aR3CxQ (http://youtu.be/rmTP-aR3CxQ)

More videos at The Signal Path:
http://www.TheSignalPath.com (http://www.TheSignalPath.com)
Title: Re: Video Review & Teardown: Siglent SDM3055A 5.5-Digit Multimeter
Post by: TiN on July 20, 2015, 02:15:26 pm
As I mentioned in vid comments, would be great to cover few more details of analog section (ADC, VREF), and/or post some hi-res photos of device's internal construction.
Somewhat priceless for repairs/hardware hacks for volt-nut's out there.

P.S. Thumbs up for frequent video's on your cat  8). Free hint: have it shiff camera lens on next video, that would explode your youtube audience thru the roof!  :popcorn:
Title: Re: Video Review & Teardown: Siglent SDM3055A 5.5-Digit Multimeter
Post by: dadler on July 20, 2015, 07:28:04 pm
Great review.

I like that this product can (sort-of) measure current and voltage at the same time.

Makes me a bit jealous, as my 3446/7XA cannot do the same.
Title: Re: Video Review & Teardown: Siglent SDM3055A 5.5-Digit Multimeter
Post by: tautech on July 20, 2015, 10:09:33 pm
Thank you Shahriar.  :-+
We never got to see under the shielding at the inputs.
Did you not get the insulated push-on croc clips with your test leads?

Software installation/USB connection order can corrupt how Windows links the ausbtmc.inf driver to the device. Now you have the driver name you can force Windows to use it.  ;)


Title: Re: Video Review & Teardown: Siglent SDM3055A 5.5-Digit Multimeter
Post by: Lightages on July 21, 2015, 04:55:38 am
I am surprised out how sloooowww it is. This would drive me crazy.

Thanks for the review.
Title: Re: Video Review & Teardown: Siglent SDM3055A 5.5-Digit Multimeter
Post by: blueskull on July 21, 2015, 07:38:39 am
Good quality, but at half the price of a 34461A it seems not to be super attractive, Especially if one can easily pick up a cosmetically new 34401A used in an automated prod line for 400 bucks.
Title: Re: Video Review & Teardown: Siglent SDM3055A 5.5-Digit Multimeter
Post by: Hugoneus on July 21, 2015, 02:52:06 pm
Thank you all for your comments. The speed of the unit can be frustrating and I wonder if there is a way for them to improve it. I hope that this can be some motivation for them to take some action on this.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: SeanB on July 21, 2015, 05:28:13 pm
Quick tip next time you test leads is to place the wire and the ends in a glass of tap water, with only the ends ( about 2cm from metal) exposed, and measure if there is breakdown between the lead and the water, via a small metal strip in the water. That shows up a real world use with sweaty hands.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Hugoneus on July 21, 2015, 05:38:14 pm
Quick tip next time you test leads is to place the wire and the ends in a glass of tap water, with only the ends ( about 2cm from metal) exposed, and measure if there is breakdown between the lead and the water, via a small metal strip in the water. That shows up a real world use with sweaty hands.

Nice, I'll use some salt water. Cheers.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: SeanB on July 21, 2015, 07:06:14 pm
just be prepared to find a lot of leads will not pass, especially at the ends. The dip in water is a test during manufacture for quality checking, though there they typically do an entire reel at a time.
Title: Re: Video Review & Teardown: Siglent SDM3055A 5.5-Digit Multimeter
Post by: Lightages on July 21, 2015, 07:06:51 pm
Good quality, but at half the price of a 34461A it seems not to be super attractive, Especially if one can easily pick up a cosmetically new 34401A used in an automated prod line for 400 bucks.

I agree. Half the price, but much lower accuracy too.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Lukas on July 21, 2015, 08:32:27 pm
Anyone looked at the SDM3055 and the 34461A next to each other? Am I the only one who thinks the from panel and screen layout are a straight rip-off?
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Armxnian on July 21, 2015, 08:59:16 pm
I complained about the same thing here: https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/450/ (https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/450/)

It samples much faster than the screen updates, why can the screen update rate not be increased?

Did you not get the insulated push-on croc clips with your test leads?
The croc clips are awful quality. First of all, there is a giant gap between the rubber shielding and the hole where you insert the probe. You have to look inside the clip and aim the probe so it can actually make good contact. If you insert the probe without looking it might not even touch the alligator clip resulting in false measurements. One of the clips is also black, so it absorbs all the light and you can't even see the hole to plug the probe into. Furthermore, after a few uses, the metal insert that is poorly soldered onto the hole fell out, so the probe doesn't stay in the clip anymore and falls out.
__________________________________________________________________
Also, my unit has rust  :-\. Sorry, only camera I have is my phone. And these pictures are after I scraped some of it off.

http://i.imgur.com/slFc4ag.jpg (http://i.imgur.com/slFc4ag.jpg)
http://i.imgur.com/8KzdusQ.jpg (http://i.imgur.com/8KzdusQ.jpg)
http://i.imgur.com/8wR20Ou.jpg (http://i.imgur.com/8wR20Ou.jpg)
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: tautech on July 21, 2015, 09:07:13 pm
Anyone looked at the SDM3055 and the 34461A next to each other? Am I the only one who thinks the from panel and screen layout are a straight rip-off?
Dave also thinks so.
https://www.eevblog.com/forum/testgear/siglent-new-bench-dmm-sdm3055/msg521967/#msg521967 (https://www.eevblog.com/forum/testgear/siglent-new-bench-dmm-sdm3055/msg521967/#msg521967)
Also member bartdinger:
https://www.eevblog.com/forum/testgear/siglent-sdm-3055a-$629-or-agilent-34461a-$1097/msg712203/#msg712203 (https://www.eevblog.com/forum/testgear/siglent-sdm-3055a-$629-or-agilent-34461a-$1097/msg712203/#msg712203)

The internals of these 2 meters are vastly different and as I've said before, I expect the same company supplied the cases.  :-//
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: dadler on July 21, 2015, 09:09:00 pm
___________________
Also, my unit has rust  :-\. Sorry, only camera I have is my phone. And these pictures are after I scraped some of it off.

http://i.imgur.com/slFc4ag.jpg (http://i.imgur.com/slFc4ag.jpg)
http://i.imgur.com/8KzdusQ.jpg (http://i.imgur.com/8KzdusQ.jpg)
http://i.imgur.com/8wR20Ou.jpg (http://i.imgur.com/8wR20Ou.jpg)

Is yours a recent or older unit?
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Armxnian on July 21, 2015, 09:13:57 pm

Is yours a recent or older unit?

Shipped from Tequipment on 04/15/2015
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: tautech on July 21, 2015, 09:20:18 pm

Is yours a recent or older unit?

Shipped from Tequipment on 04/15/2015
The last 4 digits in the SN are the actual SN, the 4 digits before them are the build date.
What are those?
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Armxnian on July 21, 2015, 09:52:47 pm
[
The last 4 digits in the SN are the actual SN, the 4 digits before them are the build date.
What are those?

Last 4 digits are 0078, the 4 digits before that is C115
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: AlphZeta on July 21, 2015, 11:29:23 pm
This meter is too slow even for casual use. While it has bells and whistles, it's no match for a decades old Keithley 196, Keithley 197. Hack, it's update speed doesn't even come close to that of a $5 DT-830. Very disappointing.

But as usual, very good review from Shahriar. Thanks!
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: tautech on July 22, 2015, 12:08:05 am
[
The last 4 digits in the SN are the actual SN, the 4 digits before them are the build date.
What are those?

Last 4 digits are 0078, the 4 digits before that is C115
Build date Jan 2015
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Armxnian on July 22, 2015, 12:28:06 am
Build date Jan 2015

The rust was an old problem, that was said to be resolved. But obviously nothing has changed. Why does a unit made in 2015 have rust? My sdg1025 also has rust, and it was from a new batch that Tequipment received from China. E115 is the date code and I'm sure it was built after the sdm3055 that I have.

Pics of sdg1025 rust:
http://i.imgur.com/FpEPGkH.jpg (http://i.imgur.com/FpEPGkH.jpg)
http://i.imgur.com/0mTvs4Z.jpg (http://i.imgur.com/0mTvs4Z.jpg)

Anyone looked at the SDM3055 and the 34461A next to each other? Am I the only one who thinks the from panel and screen layout are a straight rip-off?

Check the manual, basically identical except that the Agilent/Keysight unit has more features, and that the firmware actually works how it's supposed to...
I'm trying to like Siglent, but it's hard.

Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: tautech on July 22, 2015, 01:19:03 am
The rust was an old problem, that was said to be resolved. But obviously nothing has changed. Why does a unit made in 2015 have rust?
It HAS changed. Please consider these facts:

Siglent has confirmed in this forum they had a problem with chassis that came from their supplier.
That problem was identified as poor surface coatings on the sheet steel used for chassis manufacture.
That has been rectified.

Yours rust is very different. (checked all your images)
The chassis has been punched and guillotined as part of manufacture and the cut edges are displaying some rust as would be expected without further post manufacture treatments.
Is this really a big deal.  :-//
Galvanic coatings will restrict the progress of rust, even when breached.

Should Siglent require further coatings be added to control corrosion where the steel has been breached?  :-//
Is the galvanic protection from the now good sheet steel insufficient?  :-//


I've just checked a much much older and  :-BROKE Tek TDS2012B and the punched chassis shows EXACTLY the same rust signs, and again ONLY on the breaches and edges of the panels.

IMHO this demonstrates the galvanic protection processes as they are widely understood.


Quote
My sdg1025 also has rust, and it was from a new batch that Tequipment received from China. E115 is the date code and I'm sure it was built after the sdm3055 that I have.
The date coding does not lie. Probably old stock from the supplier or factory.

Rust, as above^^^^^^


Feedback from those involved in manufacture would be appreciated.  :popcorn:
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Armxnian on July 22, 2015, 03:21:30 am
Yours rust is very different. (checked all your images)
It's not as bad as the previous units but it still there and makes it look unprofessional. It's not just a spec of rust barely visible to the naked eye, it's there in quantity.
Is this really a big deal.  :-//
No, the unit still functions. But there is a fan, and it can blow the rust onto the board and create shorts. The chassis is thin sheet metal and rust creates weakness. Extreme conditions for something to go wrong, but why have the potential for it in the first place?


I've just checked a much much older and  :-BROKE Tek TDS2012B and the punched chassis shows EXACTLY the same rust signs, and again ONLY on the breaches and edges of the panels.
But that is a "much much" older unit. My gear is brand new and was made only a couple of months ago.


The date coding does not lie. Probably old stock from the supplier or factory.

It was backordered by Tequipment how is it old stock?

Siglent is a company that cares about a single thing, profit. They don't lead the industry and make scientific breakthroughs like other big brands. They also don't have a comparable reputation to defend like Agilent or Keithley. If you keep defending them then they aren't going to invest time or money to solve the problem. Currently Siglent is on the forum, but they don't actually do anything when a problem arises because there is always someone that shrugs it off and labels it as "not a big deal." I've held off my review on Tequipment to see if firmware issues are resolved but there hasn't been any progress that I can see.

Issues brought up by Dave or Shahriar seem to be resolved by Rigol and Siglent. But issues brought up by me, or other forum members that do not have as much publicity are simply ignored.

Tell me how I am supposed to recommend a product that has major flaws (update rate, other various firmware issues that I have posted about), has rust on the chassis, and is backed up by a company who could care less about complaints.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: tautech on July 22, 2015, 05:05:17 am
I've just checked a much much older and  :-BROKE Tek TDS2012B and the punched chassis shows EXACTLY the same rust signs, and again ONLY on the breaches and edges of the panels.
But that is a "much much" older unit. My gear is brand new and was made only a couple of months ago.
6 months actually.
Sure it is much older, the point is that at the same age as yours it would have had rust too.
But has the rust progressed further.....no.

Quote
It was backordered by Tequipment how is it old stock?

Who knows, products are made in production runs, then placed in stock and when stock is low another run is made.
Quote
If you keep defending them then they aren't going to invest time or money to solve the problem.
As usual the signature that Moderators insisted I add to my profile labels me as a fanboy.  :palm:

It is my opinion the rust is a very minor issue compared with general product development, however I've asked for further input on the subject of rust, did you miss that?

Facts are I have good relationship with Siglent, they are happy with the support I can offer and other than Siglent America I have a better understanding of English and therefore better positioned to engage with this community.
Few have any idea of the posts I point Siglent to and the work that is done behind the scenes on behalf of forum members.
I'll not blow my trumpet more, but add if you search Siglent's activity you'll find they're online several times a week.

Quote
I've held off my review on Tequipment to see if firmware issues are resolved but there hasn't been any progress that I can see.
I guess you mean this post:
https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/msg681803/#msg681803 (https://www.eevblog.com/forum/testgear/siglent-technical-support-join-in-eevblog/msg681803/#msg681803)
Quote
Tell me how I am supposed to recommend a product that has major flaws (update rate, other various firmware issues that I have posted about), has rust on the chassis, and is backed up by a company who could care less about complaints.
Did you miss their reply?
https://www.eevblog.com/forum/testgear/siglent-new-bench-dmm-sdm3055/msg675378/#msg675378 (https://www.eevblog.com/forum/testgear/siglent-new-bench-dmm-sdm3055/msg675378/#msg675378)

OK the update rate is slower than many think is adequate....... noted.

This is the first and only bench DMM to date that Siglent has produced, therefore there are bound to be improvements.
It's easy to judge this new DMM against much older, more experienced manufacturers, they set the benchmark, let's hope Siglent takes note of the improvements required.
We all look forward to the next FW.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Lightages on July 22, 2015, 05:15:26 am
I have no dog in this fight, and I don't like this multimeter. Do I think rust on a chassis is a problem? It depends if it is rust, or discoloration, or very superficial. If it is very superficial, I am not impressed and I would ask the manufacturer what they are willing to do about it. If it is deep corrosion I would demand a replacement or refund.

Tautech is trying to be up front and I believe is trying to help. PM Siglent on the forums and ask them what they think and what they want to do. You did not buy from Tautech so it is not his responsibility to fix the problem. I am sure Tautech will message Siglent and raise the question with them if you want them to contact you.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Armxnian on July 22, 2015, 05:23:39 am
Not a fight, just sharing my experiences. As usual however, I am responded with a batch of excuses and no solutions. Products look fine and dandy on the product page and reviews but you discover hidden issues when you look at them with your own eyes. It's sad that the ignorant claims labeling all Chinese equipment as crap have some validity to them. Seems to me that the public like tautech care more about the manufacturer than the manufacturer themself.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: VE7FM on July 22, 2015, 05:53:56 am
Rust or no rust the slow response of the continuity tester is enough for me to rule it out as my next potential bench meter(and I am in the market for one).
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Lightages on July 22, 2015, 06:15:15 am
I wonder how many US made products don't meet their specifications and promise? I think you know the answer. Is the rust a problem? I don't know but usually it progresses. Is it progressing and will it affect the performance? I don;t know neither. I seem to remember many US made cars rusting to nothing...

Really, stop making noise here and contact Siglent directly. They answered me and took care of me. Maybe they are a bit slow in responding but they did help me. IMHO, Siglent is not the stereotypical crap company operating behind the Great Wall. Like I said, I do not like this meter and would not buy it based on this review.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Armxnian on July 22, 2015, 06:22:22 am
Really, stop making noise here and contact Siglent directly.
Why, am I exposing something? It's not like my unit is the first one in Siglent history to have rust. It's a known problem and is still ongoing. I don't think Shahriar's unit had rust, so there was a crucial factor missing in a complete review. It's hard to objective when the stereotypes keep being reinforced.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: dadler on July 22, 2015, 06:34:57 am
Really, stop making noise here and contact Siglent directly.
Why, am I exposing something? It's not like my unit is the first one in Siglent history to have rust. It's a known problem and is still ongoing. I don't think Shahriar's unit had rust, so there was a crucial factor missing in a complete review. It's hard to objective when the stereotypes keep being reinforced.

I think you are perfectly justified in continuing to discuss the obvious rust on your unit in this thread. Seems like quite a suitable place for such information. Future prospective buyers will likely read this thread looking for objective info on the device.

When I saw Dave's review of the Siglent SDG5082 with rust, it left me with serious apprehensions about the brand. Rust is ridiculously unprofessional, especially in multiple units, as this means the QA system or supply chain is just not concerned about rust/moisture.

So I posted this thread: https://www.eevblog.com/forum/testgear/siglent-rust/ (https://www.eevblog.com/forum/testgear/siglent-rust/)

As I never heard a follow-up as to the rust situation. As you can read there, many told me the rust issue was long fixed.

It does indeed seem that this is not the case.

Is Rust a big deal? I don't know, but I won't (knowingly) buy a product that is already rusting from the factory. So perhaps it is a big deal, as it gates at least my purchasing decisions. Others may think likewise?
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Armxnian on July 22, 2015, 07:08:26 am
Thanks for the comment. In the thread you linked, the rep said that there is no more rust in their equipment. To me that seems like a blatant lie. I have two recently purchased products from Siglent, and both of them have rust.

The rust itself isn't the only problem. It's the first thing you notice when you open the unit. If something like that passed quality control, what else was ignored? I'm not buying a used 20 year old piece of test equipment off eBay, I'm buying a newely made product. It's unacceptable for it to have issues like rust, especially when the problem was brought to Siglent's attention years ago.

The unit that was reviewed in the video did not have such problems. It is unfair for future customers to not receive what they saw in a review. I'm fine with being a guinea pig for this product (lesson learned), but I won't let my purchase go in vain and not warn others.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Lightages on July 22, 2015, 08:38:29 am
Really, stop making noise here and contact Siglent directly.
Why, am I exposing something? It's not like my unit is the first one in Siglent history to have rust. It's a known problem and is still ongoing. I don't think Shahriar's unit had rust, so there was a crucial factor missing in a complete review. It's hard to objective when the stereotypes keep being reinforced.

I was trying to say that you won't get much help without contacting Siglent. I am happy that you are letting others know of the quality control problem they seem to have. it is just that repeating it here is less useful than contacting them, and possibly pointing them to this thread.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Muttley Snickers on July 22, 2015, 09:24:25 am
As this thread is related to Shahriar's review, I would have been interested to see how the unit responded to Min/ Max/ Probe Hold readings with voltages applied to get an indication as to what level of variation was necessary for the unit to record a change in the reading. His tests indicated that a variation of 5 Ohms or more was required in resistance mode before the unit recorded the change but at what level would it require for voltage, maybe I missed it.

Also I wondered what if any delay was incurred between a triggered event and the actual firing of the trigger output which to my understanding is somewhat user configurable, this may be of importance for anyone intending to utilise the unit for basic sorting or pass/fail applications.

It's a shame that we dont have a Batronix here because they were offering a 30 day trial on the unit and I do have the page saved on the other computer, I can assure you that I would have taken a month off work if necessary to rigorously put one of these units through a number of torture tests, fortunately others are now doing it for us.

Many thanks to Shahriar for another fantastic journey.... :-+

Muttley
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: tautech on July 22, 2015, 09:26:06 am
I was trying to say that you won't get much help without contacting Siglent.
Done.  ;)
See post:
https://www.eevblog.com/forum/testgear/siglent-rust/msg714775/#new (https://www.eevblog.com/forum/testgear/siglent-rust/msg714775/#new)
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Hugoneus on July 22, 2015, 01:00:39 pm
I didn't expect this to become such a heated discussion!  :scared:

I think the biggest issue with this unit is the speed at the moment. Imagine if it was 10 times faster then we would probably be a lot more forgiving of its other shortcomings. Either way as consumers we can provide feedback, buy what we think is best for us and manufactures can chose to either respond to our voices and choices, or not.
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Muttley Snickers on July 22, 2015, 02:02:00 pm
All else aside it does have a cat rating for 600 pats and 1000 purrs.

(https://www.eevblog.com/forum/testgear/siglent-sdm3055a-5-5-digit-multimeter-review-teardown-experiments/?action=dlattach;attach=162102;image)
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Lukas on July 22, 2015, 05:25:41 pm
I didn't expect this to become such a heated discussion!  :scared:

I think the biggest issue with this unit is the speed at the moment. Imagine if it was 10 times faster then we would probably be a lot more forgiving of its other shortcomings. Either way as consumers we can provide feedback, buy what we think is best for us and manufactures can chose to either respond to our voices and choices, or not.
I'm wondering whether the sluggishness is because of the slow ADC, lack of processing power, inefficient software or a combination of all of them...
Title: Re: Video Review & Teardown: Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter
Post by: Armxnian on July 22, 2015, 09:56:39 pm
I'm wondering whether the sluggishness is because of the slow ADC, lack of processing power, inefficient software or a combination of all of them...

The "slow", "middle" and "fast" settings control the number of power line cycles as mentioned in the video. The ADC takes 5, 50 or 150 readings respectively. I don't think this has anything to do with how fast the multimeter displays a new value on the screen. If you look at some of the higher end meters like the new Keysight, it can take up to 50,000 readings per second, and the new Keithley can take up to 1,000,000 readings per second. Imagine the screen updating at that speed. You would not be able to process any of the individual values. And since the LCD screen has a limited refresh rate, it would be a blurry mess. On the other extreme, the ADC can sample at 1 time per second but the screen update at 5 times a second. It would just display the single value 5 times. The screen update rate could be a function of the nplc setting that is set in the firmware, meaning it can be adjusted for speed. I'm guessing this is how it works but maybe someone with more knowledge can chime in.