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Hi everyone,
Can you suggest me a good bech top multimeter for around 1000 USD. I work on designing highly sensitive circuits, and I need a precision bench top multimeter. So, If I can measure uVs, uAs and beyond that, It would be very beneficial for me. Also, It would be wonderful If I can measure capacitances like at least 1pF.
What do you recommend? Rigol's DM3068 and Siglent's SDM3065X look good but I don't know if there is any alternatives for around 1k USD.
Thanks in advance.
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#1 Reply
Posted by
beanflying
on 20 Dec, 2022 07:23
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There is a phrase that applies here Opinions are like Bums everyone has one
I would in your case consider a decent used LCR meter because most Bench DMM's Capacitance is an afterthought or not that accurate in particular at low values. If this is a must have then you need a more dedicated meter IMO.
Depending on what perception you might want to create should you have clients visiting your lab stickers and brands might matter a little so used recent Agilent/Keysight or Keithley meters might be well worth considering over new Siglent/Rigol etc.
There will be no wrong choice but more a case of what might be a better or worse compromise.
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While the Keithley DMM6500 is without doubt a great meter, as bean points out, if you want good capacitance measurement, especially in the range the OP mentions, you need a separate LCR meter.
A used Agilent 34401A with cal history and say, an Iso-Tech LCR819 would cost less than $1000 in most markets, I should think. Iso-Tech isn't a premium brand, but you'll not get a premium one for the money, and its stats beat the pants off the DMM6500 wrt capacitance measurements.
If you want new for both, you'll have to look at the Chinese brands like Siglent, Rigol, maybe even Uni-T for the LCR.
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for now the 34401a are selling pretty high, unless you pick an very good deal, good and bright VFD and capacitors in the psu changed, and lucky if you have one who's been calibrated some years ago
At this price, grab the 34410a or 34411a meter instead, and yes grab yourself an dedicated lcr meter like an DE-5000,
Capacitances on DMM are not the most precise
I would avoid the 34461a 34465a i think they suffer from a main Spear .... mcu failure over time ... discussed here
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#5 Reply
Posted by
nctnico
on 20 Dec, 2022 12:42
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I just bought a new Keithley DMM6500 for 1200€ ( https://eleshop.eu/keithley-dmm6500.html ) , and personally I think it is the best bench multimeter for the price that is currently available.
Agreed. But for measuring low capacitances, an LCR meter is the right tool. A more specialised meter for measuring low voltages and currents might be a better choice though.
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But for measuring low capacitances, an LCR meter is the right tool. A more specialised meter for measuring low voltages and currents might be a better choice though.
I'd be amazed to see a new microvolt/microammeter within the specified price range. The OP hasn't yet mentioned whether used meters are an option?
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#7 Reply
Posted by
jonpaul
on 20 Dec, 2022 13:56
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Bonjour cher Monsieur
can you please inform
max,min I, V, capacités to measure?
interface eg Ethernet wifi, RS232, HPIB?
# digits?
Application needs or ignores Infosec?
We can better advise.
Jon
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#8 Reply
Posted by
BillyO
on 20 Dec, 2022 14:00
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But for measuring low capacitances, an LCR meter is the right tool. A more specialised meter for measuring low voltages and currents might be a better choice though.
I'd be amazed to see a new microvolt/microammeter within the specified price range. The OP hasn't yet mentioned whether used meters are an option?
The OP said he wanted to be able to measure uA and uV as well as down to 1pF, he did not say he needed 6.5 digits of accuracy @ 2uV or 1pf resolution while measuring a 100uF capacitor. Almost any 6.5 digit meter will give you the ability to resolve down to .1uV and 1pF and certainly down to 0.001 uA. Heck, even my cheap SDM6055 will, the SDM3065X will certainly. Both are under $1K new and I'll bet you could do considerably better on the used market. Before we go assuming he needs a 1uV or a 1pF range perhaps we should ask.
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Sure But an bench dmm going down to 1pf with real precision .... i want to see that
6.5 digit doesn't warranty everything you throw at ...
It an useful tool, but very limited in precision ... i never use any capacitance test on every meter i have, one bad mistake and you pooof an input ... way more expensive than using an lcr meter
Unless you use big models / brand
The dmm works with R-C timing, nothing like testing at 100, 120, 1k, 10k, 40k, 100kHz ... or test coils etc ...
If the op wrote very sensitive measurements , it's another game, you have to work in kelvin mode, you want micro volts you have dedicated meters for that, you want micro amps ... same thing
Even a 6.5, 7.5, 8.5 digits meter have its limit, you can't have everything in the same instrument, same for LCR meters, to have an 1 pf resolution, you'll pay a lot ... never saw that resolution under 1K $$$
Not some publicity gimmick loll
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#10 Reply
Posted by
Kleinstein
on 20 Dec, 2022 17:19
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1 pF resolution is not really a big deal and most LCR meters have no problem here. Most LCR meters do capacitance better than a 6 digit DMM. A big difference here is having a defined frequency: with many capacitors the capacity is frequency dependent to an extend that better than 1 % accuracy only makes sense together with a defined frequency.
1 pF range relsolution needs care (e.g. relative measurement) with the probes / cables - normal probes may already add some 20 pF.
Another point one gets with a 6 digit and some 5 digit meters is voltage readings with high impedance (e.g. >10 Gohm). Up to which voltage depends on the meters (e.g. 20 V for the SDM3065, 10 V with the DMM6500, AFAIK 2 V with a SDM3055).
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#11 Reply
Posted by
mawyatt
on 20 Dec, 2022 18:14
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One can measure ~5pF with maybe ~1/2pF uncertainty with a KS34465A, however this require extremely stable fixtures, cables, carefully nulling and such. Here's an example with an Venkel COG 4.7pF (~4.6876pF with IM3536 LCR Meter).
A better solution for the OP is a quality DMM and an LCR meter (or a NanoVNA), here's a modest cost DE-5000 with a stable fixture measuring the same 4.7pF COG 0603 cap.
Anyway, hopes this helps.
Best
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#12 Reply
Posted by
jonpaul
on 21 Dec, 2022 01:10
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bonjour à tous
âgée 100% on 34465a great instruments, paid $1000 for one that was under warranty, and failed, black readout intermittently
Keysight replacement was a new one plus CAL certificat.
Low capacity...as we designed and manufactured very high CMRR low C transformers, we had to test down to 0.3 pf.
The Keysight 34465a can easily see << 1 pF.
Any pF measurement needs
1/ solid fixed test fixture, no wires
2/ 3 terminal guarded or Shielded measurement
3/ Fmeas 10khz >>>500 MHz
4/ HP 4195A network Spectrum Analyzer has several impedance test sets. Can easily measure 0.1 pF.
hope that the information is useful
Bon Soirée
Jon
We used the fine HP 4332A LCR meter with a FS 3 pF, but the 1960s Tek LC130 dual oscillator LC meter is excellent and has 75 pF lead comp.
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#13 Reply
Posted by
rsjsouza
on 21 Dec, 2022 01:37
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Capacitance measurements on a multimeter are quite often just a quick status check (just like the hfe measurements). The LCR is the better option here, and accurate and versatile units (up to 100kHz) can be had for very reasonable money (~US$100).
As for bench options, the Keithley has gained a good reputation around here. Having worked only with modern Keysights or much older Tektronix units, I can"t compare.
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#14 Reply
Posted by
mawyatt
on 21 Dec, 2022 02:37
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We have both a DMM6500 and three KS34465A (another story), so can "speak" from actual use rather than speculate. Both types are exceptional instruments, and one can't go wrong with either as both are strong performers in actual use.
Just did the same "experiment" with the same Venkel 0603 COG 4.7pF capacitor as shown above, the DMM6500 reads 4.866pF while the KS34465A reads 4.915pF, both average of 1,000 readings. The DMM6500 is easier to get a good null of the fixture and cable parasitic capacitances, but both require extremely stable fixture and cables positions for this level of measurement.
Again, this is not something we would recommend relying on these low capacitance measurements to be reasonably accurate. The better solution is a proper LCR Meter (DE-5000) or/and VNA (NanoVNA).
Best,
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Hi everyone,
Thank you very much for the answers.
I wish I had not written capacitance measurement at all
. Well, it is good to have good capacitance measurement but it is not a must.
. I have DT71 handheld LCR meter but it is not very reliable as you guess
Precise current and voltage measurement is the most important thing for me. If I can measure nV or nA, It would be wonderful
I never work with high voltages or currents, so it is not very important. I will use it in my own lab so, as long as it has a connection for automatic data acquisition it is enough for me
DMM6500 looks good. I asked local distributor to send me a quotation. Probably they will ask for ~1500 euro
I found a Fluke 8808A/SU for 900 USD from a local distributer but it's production is ended as far as I understand, I don't know if it is a bad thing.
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#16 Reply
Posted by
Kleinstein
on 21 Dec, 2022 08:59
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The Fluke 8808 is a bit special in that it still uses a more sampling ADC and analog filtering. One kind of has to choose between slow response with the filter or extra noise bandwidth without it. I can fully understand the end of production and would not consider it, except for a direct 1:1 replacement or if one needs the sampling feature.
Measuring down to the nA is no principle problem - though it depends on the meter which current ranges are offered. Especially the more low cost meters tend to cut costs by offering only few current ranges.
Getting to the nV range is tricky. This is not just the electronics, but also the terminals and cables. Quite a few meters offer 100 nV resolution, but much better needs expensive special meters (mainly the Keithley 2182 / KS 34420 (if still available) - but that is a different price class).