Keithley 2100,2000, etc or Chinese bench multimeters?

[djsb]

I'm looking to buy a 6.5 digit bench multimeter. I've been looking at the Siglent SDM3065X, Hantek HDM3065 and similar. But I'm also drawn to the Keithley/Tektronix 2000 series. I've read here that the keithley has this scanner card project available

https://www.eevblog.com/forum/circuit-studio/example-project-relay-scan-card-for-k2000-dmm/?all

Now I'm thinking maybe a Keithley would give me more upgrade options via community add ons etc.

Are the Keithley multimeters a better investment and can spares still be bought (IE display etc) for them. What is your favourite Keithley model and why? Thanks.

[ch_scr]

Take care, Keithley 2100 & 2110 are actually Picotest M3500A/M3510A. Not that they are bad meters per-se, but one wouldn't necessarily pay "Keithley money" for them.
For the data-logging / switch card capabilities, this has to be seen in context: it usually necessitates a semi-permanent setup (of the stuff "to be measured"), usually one that's powered on for a long(er)-ish time and connected to some kind of computer running for that time as well, and the software setup to log / display that data.
In my experience, the "general bench" is not a good place for that, as it will be in the way there, and blocking the use of the bench meter to boot!
So at least I wouldn't advocate to restrict the "general bench DMM" selection by that capability.
Which brings us to that, capabilities - e.g. if you do audio stuff, maybe look at the Keithley 2015 THD.
But more generally, what do you (want to) use it for? Answer that, and people will be able to give better advice.

Edit: For the Keithleys, the VFD's are usually unobtanium. Look at the venerable HPAK 34401A, the "general recommendation" 6 1/2 digit used market DMM, and replacement VFD's are available (except for the very early, all-red input jack model) for it, too.

[BeBuLamar]

Keithley is an American company but don't they make their meters in China too?

[coromonadalix]

34410a 34411a  vfd's clones can be bought  they are very good meters to,   you have the vfd less of them  the L4411a ...

but oldies like them,  vfd age is often a problem ...  check have to be done for caps and vfd's  looks, if a seller shows  it  and you see pass tests

and prices has gone bonkers ...  repairability too  in more recent stuff / models,  no schematics etc ...  i would go to  34401a 34410 and 34411, some k2000 models have been reversed

i'm waiting for a Siglent sdm3065   well see  .... but the reference voltage used is no par with the oldies with lm399 or the ltz1000 (3458a)

For the Siglent  well design capture software and automate tests with it

Keysight has lost, in their  benchvue softwares or "the old  dmm utility was better",    K2000 ??  unless you do Labview and other softwares  ??


For scanners cards,   you do have open projects who could help lower purchases costs if you need  multiples inputs,  like the posted project link

34970a was good too ...  but the problems  for all of them (cards options) is card costs ... some are unobtanium and very expensive, they where reversed too if i recall


evaluate your need for the very long time you may need them ...   and mostly calibrations,  you can or could have big surprises ...

I don't thrust any of the 34461 or 65 models,  some reliability problems with them, give me one   i'll get rid of it.

DMM6500 7500 have good comments

unless you go  pxi / pxie  mainframes meters ?? calibration prices are way to excessive


EDIT   this software is very good :
https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/

[2N3055]

i'm waiting for a Siglent sdm3065   well see  .... but the reference voltage used is no par with the oldies with lm399 or the ltz1000 (3458a)

Rigol DM3068 and Siglent SDM 3065 also use LM399...

[KungFuJosh]

I have the SDM3065X, and it's great. If you want to make good comparisons, and you care about a scanner card, look at the SDM3065X-SC version that comes with the card.

Besides that, if you want Keithley, look at their DMM6500 model.

Siglent also has a new model coming out - the SDM4065A which appears to compete more directly with the DMM6500.

Whatever you choose, I would make sure it's compatible with TestController, as that will be better than most logging software, and it's free and made by EEVblog user HKJ.

Thanks,
Josh

[coromonadalix]

test controller support a tons of meters, his maker is in this forum too,  witch is a very good thing     you can email him ...

I'm not so sure when you add scanner cards ...  check in it's supported models / option  ...

[KungFuJosh]

test controller support a tons of meters, his maker is in this forum too,  witch is a very good thing     you can email him ...

I'm not so sure when you add scanner cards ...  check in it's supported models / option  ...

You could possibly add support for that sort of the thing by editing the device definition file (if it's not already supported).

When I'm more ambitions and/or smarter, I'll try adding my IM3570 to it.

[nctnico]

I'm looking to buy a 6.5 digit bench multimeter. I've been looking at the Siglent SDM3065X, Hantek HDM3065 and similar. But I'm also drawn to the Keithley/Tektronix 2000 series. I've read here that the keithley has this scanner card project available

https://www.eevblog.com/forum/circuit-studio/example-project-relay-scan-card-for-k2000-dmm/?all

Now I'm thinking maybe a Keithley would give me more upgrade options via community add ons etc.

Are the Keithley multimeters a better investment and can spares still be bought (IE display etc) for them. What is your favourite Keithley model and why? Thanks.

Test equipment is never a good investment. And don't get to excited about having schematics and/or the really old stuff with crappy displays and very little functionality. Repairing equipment takes time which eats in to getting more useful things done.

As ch_scr wrote: what do you want to do with a 6.5 digit DMM? What measurements do you want to make? Which features are important to you? With that, people can give useful recommendations instead of throwing random model numbers against the wall and see what sticks.

[djsb]

Thanks for all of your replies.
I'm going to take some time to do some research into what my essential requirements are. I will wait for the Siglent SDM4065A to arrive at my local distributor (Telonic) and read up on a few reviews. Will also give me time to get the cash together.

[Caliaxy]

i'm waiting for a Siglent sdm3065   well see  .... but the reference voltage used is no par with the oldies with lm399 or the ltz1000 (3458a)

Rigol DM3068 and Siglent SDM 3065 also use LM399...

But not aged, allegedly (at least not in Siglent SDM3065), which makes them prone to drift in time, requiring more frequent re-calibrations. 

[Zucca]

Are the Keithley multimeters a better investment and can spares still be bought (IE display etc) for them. What is your favourite Keithley model and why? Thanks.

A K2001 with schematics and service manual available, it makes automatically on the top on the list.
The most hackable 7.5digit DMM on the planet!

I am almost finished with the restoration of one unit, soon I will be selling it... stay tuned.

[2N3055]

i'm waiting for a Siglent sdm3065   well see  .... but the reference voltage used is no par with the oldies with lm399 or the ltz1000 (3458a)

Rigol DM3068 and Siglent SDM 3065 also use LM399...

But not aged, allegedly (at least not in Siglent SDM3065), which makes them prone to drift in time, requiring more frequent re-calibrations.

What do you mean "more frequent" calibrations?
If reference is aged all you get is less drift on first calibration after a year.
After DMM is a year or two old, they all drift the same from that point on.
Aging is only accelerating initial drift, it does not make device better long term.

If you are aging and sorting you can pick best ones and then it would make the slight difference.
Which is not what happens for entry level 6.5 digit instrument even on big brands. For KS 3458 they will do it. For 34461 not really. Only some pre-aging.
Maybe KS 34465 has aged and selected LM399 because it claims better specs than 34460/61.

[zrq]

K2001 (and M) sometimes appear on ebay for a bit less than $800 so it's indeed a great value meter, but the voltage range noise as tested by myself suggests it's rather disappointing for reading the 7th digit (the noise can hardly be averaged down to 0.1ppm of range).

[nctnico]

i'm waiting for a Siglent sdm3065   well see  .... but the reference voltage used is no par with the oldies with lm399 or the ltz1000 (3458a)

Rigol DM3068 and Siglent SDM 3065 also use LM399...

But not aged, allegedly (at least not in Siglent SDM3065), which makes them prone to drift in time, requiring more frequent re-calibrations.

Tony Albus shows that in a review of a GW Instek GDM-9061.

Around 16:00 he compares the GDM-9061 against the Siglent SDM3065 and the Siglent does seem to drift a bit.

[Caliaxy]

i'm waiting for a Siglent sdm3065   well see  .... but the reference voltage used is no par with the oldies with lm399 or the ltz1000 (3458a)

Rigol DM3068 and Siglent SDM 3065 also use LM399...

But not aged, allegedly (at least not in Siglent SDM3065), which makes them prone to drift in time, requiring more frequent re-calibrations.

What do you mean "more frequent" calibrations?

As needed to keep it on par with the ones with aged references (if precision matters that much).

If reference is aged all you get is less drift on first calibration after a year.
After DMM is a year or two old, they all drift the same from that point on.
Aging is only accelerating initial drift, it does not make device better long term.

If you are aging and sorting you can pick best ones and then it would make the slight difference.
Which is not what happens for entry level 6.5 digit instrument even on big brands. For KS 3458 they will do it. For 34461 not really. Only some pre-aging.
Maybe KS 34465 has aged and selected LM399 because it claims better specs than 34460/61.

Yes, the drift slows down with time, until a point when it's not relevant anymore. SDM3065X only provides data for the first year (on par with 34461, indeed). Looking at the KS datasheets (for 34461 and 34465), the drift slows down a bit in the second year (by 25%). DMM6550 is more impressive, in two years drifts as much as the others in one. But they are all very small numbers.

[2N3055]

i'm waiting for a Siglent sdm3065   well see  .... but the reference voltage used is no par with the oldies with lm399 or the ltz1000 (3458a)

Rigol DM3068 and Siglent SDM 3065 also use LM399...

But not aged, allegedly (at least not in Siglent SDM3065), which makes them prone to drift in time, requiring more frequent re-calibrations.

Tony Albus shows that in a review of a GW Instek GDM-9061.

Around 16:00 he compares the GDM-9061 against the Siglent SDM3065 and the Siglent does seem to drift a bit.

I don't think what he shows is relevant in any way.

He stacked 10 instruments , including SDM3065, so close that air passages are blocked and instruments are heating each other in addition to not having any airflow. GDM-9061 is on desk with normal air flow.
So any "drifting" relative between these two instruments is irrelevant as a data point.

And you know that...

[nctnico]

i'm waiting for a Siglent sdm3065   well see  .... but the reference voltage used is no par with the oldies with lm399 or the ltz1000 (3458a)

Rigol DM3068 and Siglent SDM 3065 also use LM399...

But not aged, allegedly (at least not in Siglent SDM3065), which makes them prone to drift in time, requiring more frequent re-calibrations.

What do you mean "more frequent" calibrations?

As needed to keep it on par with the ones with aged references (if precision matters that much).

I don't think that will work. For as long as the drift hasn't made the readings go out of specification, there is no reason to adjust. A reference just needs to age to get rid of the initial drift.

[2N3055]

Yes, the drift slows down with time, until a point when it's not relevant anymore. SDM3065X only provides data for the first year (on par with 34461, indeed). Looking at the KS datasheets (for 34461 and 34465), the drift slows down a bit in the second year (by 25%). DMM6550 is more impressive, in two years drifts as much as the others in one. But they are all very small numbers.

I am afraid you misunderstood what some of these specifications mean in datasheets.
1 year and 2 year columns do not mean drift in 1st and 2nd year. These are maximum errors with 1 year and 2 year calibration intervals.
Drift basically drops exponentially with time. After reference is 2-3 years old drift will be in low ppm range.
Other components will settle too.

[temperance]

Also check the price for extra PC software if you need that. Tek's Kickstart software will cost you €177 annually or over €500 for a perpetual license. EasyDMM for a Signlent is free.

[KungFuJosh]

Around 16:00 he compares the GDM-9061 against the Siglent SDM3065 and the Siglent does seem to drift a bit.

Yeah, and the Siglent only had 5 minutes of warm up time. That's not enough for either of the meters to be perfectly stable.

Next questions: Which reading was more accurate? What's the certified value for his ref? Is it in cal still? Is that reference really that stable?

That Instek looks pretty nice though. Might look good on my bench next to my SDM3065X. 😉

Also check the price for extra PC software if you need that. Tek's Kickstart software will cost you €177 annually or over €500 for a perpetual license. EasyDMM for a Signlent is free.

Yes, but EasyDMM sucks compared to TestController, which is also free.

[temperance]

Around 16:00 he compares the GDM-9061 against the Siglent SDM3065 and the Siglent does seem to drift a bit.

Also check the price for extra PC software if you need that. Tek's Kickstart software will cost you €177 annually or over €500 for a perpetual license. EasyDMM for a Signlent is free.

Yes, but EasyDMM sucks compared to TestController, which is also free.

I never tried EasyDMM.

[djsb]

The dual measurement function of the GDM-9061 could be useful. It also has the GPIB option but no multiplexer option. The better displays on the Siglent and GW-Instek are a plus over the limited Keithley displays. I have an Instek GPP-4323 which it would sit nicely alongside.

[KungFuJosh]

The dual measurement function of the GDM-9061 could be useful. It also has the GPIB option but no multiplexer option. The better displays on the Siglent and GW-Instek are a plus over the limited Keithley displays. I have an Instek GPP-4323 which it would sit nicely alongside.

The Siglent and the Keithley DMM6500 all support dual measurements. I think you should consider a modern model from those 3, and then it's hard to go wrong. Siglent is the least expensive, then the Instek, and most expensive (of course) is the Keithley. Personally, I want all 3. 😉

[tautech]

Around 16:00 he compares the GDM-9061 against the Siglent SDM3065 and the Siglent does seem to drift a bit.

Yeah, and the Siglent only had 5 minutes of warm up time. That's not enough for either of the meters to be perfectly stable.

Next questions: Which reading was more accurate? What's the certified value for his ref? Is it in cal still? Is that reference really that stable?

That Instek looks pretty nice though. Might look good on my bench next to my SDM3065X. 😉

Also check the price for extra PC software if you need that. Tek's Kickstart software will cost you €177 annually or over €500 for a perpetual license. EasyDMM for a Siglent is free.

Yes, but EasyDMM sucks compared to TestController, which is also free.

Yet EasyDMM is easier to use should you not have any programming skills.