SDM3045X vs SDM3055 Wrap-Up

[soulhuntre]

Hey all!

So I am adding a bench DMM to my setup. I have a SIGENT power supply (3303X-e) and a SIGENT scope (1104X-e). I woudl prefer to stay with SIGENT. The obvious choices for me are the SDM3045X and the SDM3055. I know there are a number of threads that go way deep in the weeds on these, but I am a simple guy and I know others have the same choice to make... so I am thinking a nice, simple wrap up thread woudl help?

 So far, here is what I have culled.

SDM3045X

* $389 US as of now
* Is an "X" model, so maybe better matched to their new gear, MAY be a newer design, MAY be better supported with FW updates
* Lacks a DC filter that the 3055 has
* Maybe less accurate due to a less accurate reference internally
* Does not have a fan, so is silent

SDM3055

* $469.00 US as of now
* Is not listed as an "X" model, but newer stock may come with "X" compatible stacking feet
* More accurate
* DC filter
* Has a fan, maybe noisy (some of the time? All of the time?)

In short, it appears the difference is under $100 and comes down to accuracy, support and noise.

Questions

* The Impression is that the SDM3055 is "older" and while a better unit on paper may not enjoy the sort of improvements that a newer design has?
* Is the accuracy difference something most folks will notice in daily use?
* Is the SDM3055  well supported?

Thanks! I know this thread may SEEM redundant, but I don't think it is.

Ken

[BillB]

Hi Ken,

I have both models and have chimed in on a few threads asking this question.  User alexvg has a recent thread on hacking and improving the 3055 where he mentions that the 3045X is using the 3055 design (same PCB?) with lesser capable components.  I myself have compared functionality and have found them to have almost the exact same feature set.  So, don't assign any value to the 3045X being a newer design.

I think you've summarized the decision well.  The answer to me is clear: if at any point you need the higher accuracy for some measurements and can swing the $80 difference, then the 3055 is the right choice.  If you are a hobbyist with a tight budget and don't need the precision then you won't be disappointed with the 3045.
   

[soulhuntre]

Side note: Anyone know why they reference to a SDM3055X-SC and SDM3055X sometimes? Does the CURRENT stock look like this photo or the old version?

[tautech]

Side note: Anyone know why they reference to a SDM3055X-SC and SDM3055X sometimes?

Because there are other models exclusively for the Chinese market, these are mistakes ^.
To this day so to avoid confusion that a new 3055 may have been added to the lineup the addition of X to the model # has never been added.

Does the CURRENT stock look like this photo or the old version?

All stock for some years have the X style bumpers/horns.

Good research summary soulhuntre and I endorse what Bill said.

https://int.siglent.com/products/digital_multimeters/

Thread for all 3 models
https://www.eevblog.com/forum/testgear/siglent-new-bench-dmm-sdm3055/

[Electro Fan]

Looks like siglent.com shows:

https://siglent.com/products-overview/sdm3055/
and
https://siglent.com/products-overview/sdm3055x-e/

Sort of hard to spot differences other than the X-E seems to have a lower price (at least in China:  From ¥3,780 vs From ¥4,380).

One other slightly interesting spec is that the Siglent North America SDM3045X spec sheet gives (length×width×height ) dimensions of 293.75 mm×260.27 mm×107.21 mm and the SDM3055 spec sheet gives dimensions of 282 mm × 260 mm × 105 mm, ie the 3055 is slightly smaller, and the SDM3045X weighs 3.76Kg vs the SDM3055 weight of 3.33Kg - all of which is interesting given than the 3045X does not have a fan and the 3055 does have a fan but weighs less; maybe the 3045X needs a slightly larger chassis to passively cool itself?  Or maybe there is some error in the dimension and weight specs...?

https://siglentna.com/resources/documents/digital-multimeter/

[Kleinstein]

The difference in the dimensions could be lost in translation (calculating to inches, round and back to millimeters). The same may have happened to the weight. Here it could also be a different transformer model.

The DM3045 specs show some down-sides:
The burden voltage is quite high in some ranges (e.g. 600 mA). They show the same 1 Ohms shunt value for the 600 mA range in the 3045 and 200 mA range in the 3055. So there could also be more and possibly troublesome self heating effects.

The high Z mode is only available for 600 mV. However having the option of high Z mode at all is not standard for a 60000 count dmms - so one can see also see it as a good point (compared to other cheap meters).

AFAIR the x-e versions are different in having less interfaces.

[tautech]

The difference in the dimensions could be lost in translation (calculating to inches, round and back to millimeters).

Either way the differences in measurements is minimal.
Here I lined up all three models, 3045X on top of an early 3055 without the later X series feet/bumpers.

The same may have happened to the weight. Here it could also be a different transformer model.

I think other than 3045X missing the fan the guts of both models are very very similar.
Some posted pics of each.
SDM3045X

SDM3055

[Zorc]

I would love to have a good bench DMM as well but I still can't convince myself to spend the money for it....

Mostly using a Brymen BM869s and Uni-t UT61e as second on my bench...and I don't really need (at the moment) anything better.

Considering the price difference  I would at least go for the 3055x and not the 3045x. Although if I ever really 'need' a bench DMM I would probably be tempted to go 6.5 digits.
And then there will be another dilemma to consider, the price difference between the 3065x and say for example the keithley dmm6500  

[BillB]

I would love to have a good bench DMM as well but I still can't convince myself to spend the money for it....

Mostly using a Brymen BM869s and Uni-t UT61e as second on my bench...and I don't really need (at the moment) anything better.

Considering the price difference  I would at least go for the 3055x and not the 3045x. Although if I ever really 'need' a bench DMM I would probably be tempted to go 6.5 digits.
And then there will be another dilemma to consider, the price difference between the 3065x and say for example the keithley dmm6500

It is difficult to justify a bench DMM when you only need basic measurement features, especially when such capable devices as Dave's 121GW are available for about half the cost.  However, the bench DMMs do have a few compelling features such as larger easier-to-read displays, 4-wire measurement, logging, remote control (USB/Ethernet connectivity), and SCPI programmability.  I also find that the bench DMMs have a harder time of sprouting wings/legs and disappearing from the lab bench.