Siglent Bench DMMs SDM3065X, SDM3055 and SDM3045X

[slavoy]

And I would pay under 800 incl. VAT for the siglent, so I pulled my trigger now on it.
One day, when I need more, the cards will be reshuffled.
I will post my experiences with the SDM3065X here from time to time.
Thanks to all who opened my eyes (not as easy as I thought), especially skander36.

I was in a similar dilemma 7 months ago... new multimeters from top brands were terribly expensive for me, and some were unavailable in PL. There were no used ones in good condition and at a reasonable price. There happened to be a promotion for the 3065X at around 780 EUR, so I took a look at the specifications and simply went for it. I'm satisfied and aware that it's not top-of-the-line equipment, but it's actually quite decent and sufficient for my needs. We'll see how it performs after calibration and over time, but I think it will be fine. I don't regret the purchase 

[skander36]

I wish you luck with the calibration.
Mine is so bad with the tempco so it cannot be calibrated at the 6.5 digit level. Even by Siglent.
I also did not exclude a fault of my equipment.
Maybe yours are good ones.

[Martin72]

Mine is so bad with the tempco so it cannot be calibrated at the 6.5 digit level. Even by Siglent.

According to the protocol it has passed...

[skander36]

Mine is so bad with the tempco so it cannot be calibrated at the 6.5 digit level. Even by Siglent.

According to the protocol it has passed...

It pass because the specs are large, but it can't be adjusted as the others can. Any adjustments you do on it, in 30-40 min will drift away.
On paper it said that has reading 1.800045 and my reads is showing 1.799923 and continues to go down, while the others stand still at 1.80000 and 1.79999.

[Martin72]

Hm-hm...

[KungFuJosh]

It pass because the specs are large, but it can't be adjusted as the others can. Any adjustments you do on it, in 30-40 min will drift away.

Have you tried leaving it on for any extended period of time? Like a day or a week?

I'm not kidding, I'll take that DMM off your hands. Let's trade something fun. 😉

[skander36]

It pass because the specs are large, but it can't be adjusted as the others can. Any adjustments you do on it, in 30-40 min will drift away.

Have you tried leaving it on for any extended period of time? Like a day or a week?

I'm not kidding, I'll take that DMM off your hands. Let's trade something fun. 😉

It was aquired in Nov. 2018. You can imagine that it was on for weeks ...
It is on company inventory so it's complicated to sell.

[Martin72]

Tadaaa..

[Martin72]

First measures with the DMMCheckplus...
Not bad, but: I couldn´t find quickly the duty cycle measure function ?

[tautech]

Tadaaa..

Pop the latest FW into it.
https://int.siglent.com/download/firmwares/?ProId=24

[Martin72]

Hi Rob,

Not necessary, it already has the latest firmware on it.
It was "calibrated" last month - It probably comes from a brand new production.
I will probably repeat the measurements with the DMMCheck.
According to the manual, 100PLC are to be set to achieve the maximum accuracy, I had not done that before.
Also, I had not let 90min warmup time pass, both are just made up.
And it seems to be actually so that the Siglent knows no duty cycle measurement, I have currently found nothing about it.
That would be a wish for a firmwareupdate in the future.

[TheDefpom]

For the warm up period and ambient temperature I found mine to require consideration to both, after 10 minutes it is pretty good, after one hour it got a bit better, but is only properly stabilised after a few hours really.

Changes to ambient temp of a +- few degrees will effect it slightly too, so don’t expect a reading at 19 degrees Celsius to be the same as one at 28 degrees, but that can be said for most meters anyway.

[TheDefpom]

Also on AC Measurements there is a filter option, I suggest using it too.

[Martin72]

Hi Scott,

so don’t expect a reading at 19 degrees Celsius to be the same as one at 28 degrees, but that can be said for most meters anyway.

That goes without saying, no one should underestimate the influence of (ambient) temperature on equipment.
Currently it is 21°C here...

[Martin72]

Also on AC Measurements there is a filter option, I suggest using it too.

Yepp, 3hz 20Hz(default), 200Hz.
I leave it to 20Hz for the 100Hz signal.
Aperture is not avaible in ACV and capacitance measure mode (but for resistance measure mode) and it will be set back to 10 PLC when changing the mode.
Test it again after 80min warmup (also the DMMchecker), nearly all measured values are the same (when ignoring the last digit), nice.

[MathWizard]

Does anybody else wish they could save their settings on these ? Like not having to change volume and ohms threshold for continuity everytime the machine is turned on ?

With all the hacking that goes on with equipment, does anyone on here change little things like that ?

[Martin72]

Power on default/last state, duty cycle measure, print "button"....

[TheDefpom]

Does anybody else wish they could save their settings on these ? Like not having to change volume and ohms threshold for continuity everytime the machine is turned on ?

With all the hacking that goes on with equipment, does anyone on here change little things like that ?

You can, there is a setting for "last" or "default"...

Shift->Dual (Utility) - Store/Recall - Power On (Last/Factory Default)

[Performa01]

And it seems to be actually so that the Siglent knows no duty cycle measurement, I have currently found nothing about it.
That would be a wish for a firmwareupdate in the future.

None of my lab grade bench DMM (and I have quite a few of them) supports duty cycle. Not even the humble 4.5 digit Fluke 45 has it, let alone the higher end Fluke 8846A or Keithley 2000, 2015 as well as the high end Keithley 2001/2.

Yes, the industry standard Fluke 87 has it, but not every feature that might be handy on a "swiss knife" type handheld DMM is also appropriate for a lab grade instrument. There have been times, when serious bench DMM didn't even have a continuity check - of course not, why would you want to have a 50 cent function in an expensive 6.5 digit meter, that you could easily build yourself with a battery and a buzzer?

Nowadays, lab grade DMMs tend to integrate more and more questionable functions, just to make their feature list longer. Frequency measurement is one of them. What is the use to have a frequency measurement in a precision multimeter, when the accuracy has to be specified in percent instead of ppm or ppb? Even the cheapest frequency counter as well as any serious DSO will be better than that. And it is just funny, when a meter can measure voltages more accurately than frequency...

The same goes for capacitance measurements. Yes, ir might be handy sometimes, in a pinch on site, hence a Fluke 87 has it, but in a lab? You cannot measure small capacitors. You can measure big ones, but you cannot determine their quality or functionality. It might be enough for a tinkerer who knows some workarounds (and has the time to apply them), but not for professional use.

Much more important for a precision bench DMM are the more hidden features, like the max. range, where a high input impedance (>10 GOhm) can be maintained, and the input bias current in this mode.

[Martin72]

That was a long answer to say duty cycle, no, there won't be.
No problem, it's not really a flaw.
And I already knew that you can't seriously measure capacities with it, believe me.

[KungFuJosh]

What's wrong with the frequency measurement on these DMMs? My SDM3055X-E measured my LCR's freqs with excellent consistency. For example, 10kHz came back as 9.9999kHz. Should I not trust that number?

[Martin72]

Performa01 meant it not in this way.

[movie]

Very Interesting the firmware 3.02.01.12R1. I cannot find it on the net.
It seems the latest downloadable version is 3.01.01.12R1.

[alm]

What's wrong with the frequency measurement on these DMMs? My SDM3055X-E measured my LCR's freqs with excellent consistency. For example, 10kHz came back as 9.9999kHz. Should I not trust that number?

Check the specifications for the uncertainty on that measurement if you want to know. But Performa01's point was that even a cheap frequency counter can do better in frequency, and a cheap LCR meter is much more useful for capacitance, so why put a mediocre quality frequency and capacitance function on these meters? It's not that they're useless, just not up to the standards of the rest of the meter.

[KungFuJosh]

What's wrong with the frequency measurement on these DMMs? My SDM3055X-E measured my LCR's freqs with excellent consistency. For example, 10kHz came back as 9.9999kHz. Should I not trust that number?

Check the specifications for the uncertainty on that measurement if you want to know. But Performa01's point was that even a cheap frequency counter can do better in frequency, and a cheap LCR meter is much more useful for capacitance, so why put a mediocre quality frequency and capacitance function on these meters? It's not that they're useless, just not up to the standards of the rest of the meter.

Is there something stopping them from putting in a frequency counter that's at least as good as a "cheap frequency counter"?

Has anybody done a real life comparison between a "cheap frequency counter" and one of these DMMs?

No question on the capacitance being better in an LCR meter, but it's still a nice feature to have, and the accuracy is fine for general use.