Author Topic: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500  (Read 4560 times)

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Offline hwj-d

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Interesting question for the "hobbyist", i think.

For this reason i wanted to put this question to the 6.5 digit lm399 based dmm's and my very subjective answer to it here also to the discussion:

Quote
I prefer the 6500 dmm, because its connectivity and programmable measurements and gui. It's the more modern concept. Also you can use a scannercard.

The 34465A is the more robust well developed dmm, has acal, very easy to operate via buttons on the front panel, has extended mathematical extensions. But it is what you get, gui not expandable, as far as I know. For many that's it, that's what they wont.

My problem is, that I fall in love with ltz1000 references, dreaming to build, to learn, my own dmm's, buy expensive resistors, and so on. The 6500 suits me a little bit better, but actually I would need an 8,5 digit dmm for it.

I was advised against the 7.5 digit Keysight by a more professional, because its drifts at different ambient temperatures in the 1-10 ppm measuring range. The manual acal must be used far too often. That was too for the 34465A.

But that is if you go to the limits of those instruments caused of building such references.

Now my dmm 6500 has no bluescreens anymore, and i believe it it will be even more robust in the future.

So, it depends of what type of "hobbyist" you are. If you need something robust, compact like a handheld even with more possibilities, take the 34465A.

If you are keen to experiment, keen to program, the joy of measuring also sometimes becomes an end in itself, take the 6500,

and note the price difference...  ;)

What do you think about that?
« Last Edit: February 05, 2019, 08:22:58 am by hwj-d »
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Offline MrFox

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #1 on: February 05, 2019, 06:43:39 pm »
A few important features made me choose the 6500 as my workhorse dmm, each hobbyist have different needs but those are things to consider when making a checklist...

Working with precision shunts, the 1 ohm range is very nice.

For my high power leds projects, the 12V diode max is much more usable.

The digitizer specs are far superior on the keithley, but admitedly only useful for special cases where scopes don't have the resolution/accuracy.  For me it's a  very narrow use case.

Larger buffer is great for long runnning acquisition, testing something for 24h at 1 NPLC is possible.

The switcher card expansion is compatible with the old model, easy to find on ebay.

Naming things and entering values is so much better with a touchscreen.

In canada at least, the keithley is a lot less expensive than the keysight.

On the negative:

For simple functions as a plain multimeter, direct buttons are probably more usable.

10A is only in the back.

Firmware is very young and needs improvements.

Graphing crashed on me twice. Never happened again though.

Buffer management is a little confusing because of the fragmentation, I suppose it will be solved in a later firmware.

 
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Offline hwj-d

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #2 on: February 05, 2019, 08:03:34 pm »
Thanks MrFox, for this additional points.
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Online tautech

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #3 on: February 05, 2019, 09:39:35 pm »
Irrespective of brand/model, doesn't budget play a major factor in a decision ?
And if it's high enough, new and warranty vs 2nd hand ?

Say if you spend 500 Euro on a 2nd hand unit and a new 6.5 digit bench DMM is 689 Euro........
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Offline hwj-d

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #4 on: February 05, 2019, 11:37:50 pm »
@tautech

Interesting.
On Topic: Keysight 34465A or Keithley DMM6500.
Which one of them, new, do you have for 689€ ?
 ;D
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Online nctnico

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #5 on: February 06, 2019, 12:04:47 am »
According to some Youtube videos the DMM6500 seems to have a touch screen. I have a 34461A which is related to the 34465A. When I bought the 34461A Tektronix only had older models but the DMM6500 looks mighty nice to operate so I'm not sure I would buy the 34461A again if I'd had to choose today.
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Online DaJMasta

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #6 on: February 06, 2019, 01:21:01 am »
According to some Youtube videos the DMM6500 seems to have a touch screen. I have a 34461A which is related to the 34465A. When I bought the 34461A Tektronix only had older models but the DMM6500 looks mighty nice to operate so I'm not sure I would buy the 34461A again if I'd had to choose today.

Would be interested to see it on video, but similar thoughts.  Lots of extra memory and I think I do prefer the GUI/looks of the Keithley, and the programmability I've seen demonstrated looks very nice.  While the firmware is younger, my guess is that it borrows a lot from their earlier 7.5 digit meters in the same GUI, if not almost everything, so my initial assumption would be that it feels pretty mature to use.
 

Offline kj7e

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #7 on: February 06, 2019, 01:42:11 am »
I have both a 34465A and a DMM7510.  The DMM6500 UI is very similar to the 7510, between the two I would pick the DMM6500 as its much more entertaining for the hobbyist.  I believe the difference in performance between the two is minimal.  That said, I love the 34465A, glad I have both.
 
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Online TheSteve

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #8 on: February 06, 2019, 01:47:34 am »
If you want a super stable meter with excellent build quality that just works get the Keysight. If you don't mind the occasional crash then the DMM6500 sure seems to offer the most bang for the buck. It doesn't appear to have the highest build quality but the feature set and price sure make it appealing. I would think the firmware will become more stable overtime as well.

edit - I think kj7e is right, for the hobbiest a DMM6500 would be more fun.
« Last Edit: February 06, 2019, 01:50:48 am by TheSteve »
VE7FM
 
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Offline ebclr

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #9 on: February 06, 2019, 02:51:19 am »
"have the highest build quality   :palm:


The Keithley quality is state of art
 

Offline Faith

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #10 on: February 06, 2019, 04:11:23 am »
Used to own the 34465A, played with the DMM6500 a little bit... the 34465A seems to reach stability a lot faster (even compared to the 34470A)... but I would buy the DMM6500 if I needed another bench DMM without doubt.

Really like the scripting of the DMM6500/7510!~

For hobby definitely 100% would recommend the DMM6500... much more fun to use haha. Even if the 34465A gives better readings (which isn't really by a lot), for hobby use it doesn't matter.

Only annoying thing is 10A input at the back... but really that is what handheld DMM / clamp meter / etc is for so whatever.

Anyway best is you just demo and try both and see which one you like to use best!


Edit: Just a small note, 34465A now comes with DIG option standard (50,000rdgs/sec) on latest firmware and MEM (2m memory points) is frequently given out for free too.

So it is now cheaper to own fully unlocked than it used to be, but still a very expensive DMM.

Also another consideration is support in your country.

Where I live Keysight support is super... but almost all companies under Danaher (Fluke, Tektronix, etc) have really super crap reputation for their support.

So think about that too.
« Last Edit: February 06, 2019, 04:18:19 am by Faith »
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Offline Inverted18650

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #11 on: February 06, 2019, 04:38:44 am »
I just bought a DMM7510 and its so much fun! Moreover, its such a versatile machine with deep bandwitdh and am amazing array of features. Someone recently told me, "its like a 7.5 digit digital oscilloscope and more" and they were BANG ON. Keithley DMM6500 is they way to go mate, that's even before we talk about KickStart and the added functionality it brings. You will go from "just a hobby guy" to being able to send accurate data with graphs of every characteristic you need to make it truly professional. Tempco, deviation, histograms, etc etc...it measures everything you need right out of the box (after an 1.5 hr warm up) expect inductance... its the only meter you will need on your bench

literally got here today*
« Last Edit: February 06, 2019, 04:45:38 am by Inverted18650 »
 
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Online nctnico

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #12 on: February 06, 2019, 11:30:58 am »
"have the highest build quality   :palm:

The Keithley quality is state of art
Euuhhh... Keithley is Tektronix and Tektronix is owned by Danaher. Nowadays Tektronix rebadges a lot of low end stuff.
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Offline MrFox

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #13 on: February 06, 2019, 03:44:34 pm »
"have the highest build quality   :palm:

The Keithley quality is state of art
Euuhhh... Keithley is Tektronix and Tektronix is owned by Danaher. Nowadays Tektronix rebadges a lot of low end stuff.
But the 6500 is not a rebadged low end stuff. It's clearly a derivative of their 7510 and SMUs.

Whatever tek does OEM is usually obvious.
 
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Offline hwj-d

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #14 on: February 06, 2019, 04:23:52 pm »
The instrument does not deserve a bad reputation, nor does it actually deserve to badly measuring because of remedyable shortcomings.

Edit: But frankly sayd, the 7510 is a completely different house in terms of measuring and technical construction.
« Last Edit: February 06, 2019, 04:33:46 pm by hwj-d »
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Offline kj7e

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #15 on: February 06, 2019, 04:36:52 pm »
"have the highest build quality   :palm:

The Keithley quality is state of art
Euuhhh... Keithley is Tektronix and Tektronix is owned by Danaher. Nowadays Tektronix rebadges a lot of low end stuff.
But the 6500 is not a rebadged low end stuff. It's clearly a derivative of their 7510 and SMUs.

Whatever tek does OEM is usually obvious.

While the 6500 and 7510 share almost the same UI, the hardware is not in the same class.  It's clear the DMM6500 hardware was built to a price point with the Keysight 3446[15]a target in mind.  The 6500 is very fine meter and I'm sure will endure for many years, but I also believe the Keysight equivalent has the edge in both hardware and firmware quality/stability.  If I was in the market now, I would still pick the DMM6500 over the 34465a due to the more advanced UI while still having very comparable specifications.

 
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Offline dmm2018

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #16 on: February 12, 2019, 06:23:08 pm »
Keysight 34465A/34470A has higher uncertainty in low resistance measurement.

For example:

[1Ω measurement uncertainty]
Keysight 34465A/34470A: ~0.4%
DMM6500 uncertainty: ~0.03%

[0.1Ω measurement uncertainty]
Keysight 34465A/34470A: ~4%
DMM6500 uncertainty: ~0.2%

[0.01Ω measurement uncertainty]
Keysight 34465A/34470A: ~40%
DMM6500 uncertainty: ~2%

[0.001Ω measurement uncertainty]
Keysight 34465A/34470A: ~400%
DMM6500 uncertainty: ~20%


Where I live Keysight support is super... but almost all companies under Danaher (Fluke, Tektronix, etc) have really super crap reputation for their support.
Agree... Keysight support at where I live is very good... but the support (after sales) of those claim to be Tektronix distributor is not that good.
« Last Edit: April 17, 2019, 12:20:45 pm by dmm2018 »
 

Offline HighVoltage

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #17 on: February 12, 2019, 06:41:35 pm »
I have the 34465A, the 34470A the DMM7510 and since Christmas the DMM6500
They are all really good meters.

But, right now I prefer the Keithley DMM6500, since it is the only meter I have bought with spot on calibration for voltage and resistance.

It even confirmed one of my Burster 200 mOhm calibration resistors to 0.20000x Ohm (Wow, what a surprise).
This would not work on either Keysight or the DMM7510.

But I still would keep all four of them!
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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #18 on: February 12, 2019, 10:43:15 pm »
IMHO you should use special meters to measure in milli-Ohm territory. A good LCR meter or low resistance meter would be more suitable.
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Offline dmm2018

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #19 on: February 13, 2019, 05:29:23 am »
At TESTEQUITY:

Keysight 34465A >> USD1454
Keithley DMM6500 >> USD1140

Is the 1Ω range (test current = 10mA) circuit difficult to be implemented?
 

Offline MikeP

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #20 on: February 15, 2019, 08:12:47 pm »
For example:

[1Ω measurement uncertainty]
Keysight 34465A/34470A: ~0.4%
DMM6500 uncertainty: ~0.03%

[0.1Ω measurement uncertainty]
Keysight 34465A/34470A: ~4%
DMM6500 uncertainty: ~0.2%

[0.01Ω measurement uncertainty]
Keysight 34465A/34470A: ~40%
DMM6500 uncertainty: ~2%

[0.001Ω measurement uncertainty]
Keysight 34465A/34470A: ~400%
DMM6500 uncertainty: ~20%

Where did you get this information?
 

Offline Mr. Scram

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #21 on: February 15, 2019, 09:08:53 pm »
At TESTEQUITY:

Keysight 34465A >> USD1454
Keithley DMM6500 >> USD1140

Is the 1Ω range (test current = 10mA) circuit difficult to be implemented?
The prices make it a no brainer, unless you have requirements only the Keysight can fulfil.
 

Offline MrFox

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #22 on: February 15, 2019, 10:24:51 pm »
IMHO you should use special meters to measure in milli-Ohm territory. A good LCR meter or low resistance meter would be more suitable.
I really wanted one until I saw the prices.

The bench LCR meters that are anywhere near the resolution and accuracy of the dmm6500 low resistance ranges seem to be very expensive.
 

Offline Joel_l

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #23 on: March 31, 2019, 05:17:56 pm »
I was about to pull the trigger on a Keysight 34465A when I ran across this thread. It steered me to the DMM6500 instead. My initial investigation was driving me towards the Siglent SDM3065X and the 34465a. Specmanship wise, the DMM6500 just seemed to be a clear winner at a price point between the two. I've had it a few days now and am still getting familiar with its operation, but I'm pleased with the purchase. Lot more bang for the buck. I was looking at the 34465A with the memory and digitizer upgrade which would add $$$$$$.

The only downside to me is what has been mentioned, 10A current only on the back.
 

Offline HighVoltage

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #24 on: March 31, 2019, 10:04:48 pm »
In voltage mode, the DMM6500 is a reliable 6 1/2 digit meter and it stays stable without noticable drift.
Here I was testing a very stable 10.000,040 V source.
The calibration of my DMM6500 is about 20 uV off, which is about the same offset at my DMM7510.
 
Otherwise it has proven to be very reliable so far.
The pk/pk span is about 27 uV
« Last Edit: March 31, 2019, 10:11:41 pm by HighVoltage »
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Offline HighVoltage

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #25 on: March 31, 2019, 10:10:43 pm »
At the same source, the DMM7510 shows a pk to pk of only 7 uV
But about the same offset of around 27 uV

My observation so far with the DMM7510 and DMM6500 is very good, except this calibration offset.
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Offline hwj-d

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #26 on: April 01, 2019, 11:28:00 pm »
Thank you HighVoltage. I'll take care of it. This comparison gives me hope without having the 7510. My DMM6500 shows an surprising similar result, without having my refs calibrated so far, which I still have to do.

Far behind meanwhile my Keysight 34461A. Without ACAL it shows an amazingly high temperature drift compared to the DMM6500.
« Last Edit: April 01, 2019, 11:33:05 pm by hwj-d »
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Offline alex-sh

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #27 on: April 23, 2019, 10:35:04 am »
What do you think about that?


Absolutely DMM6500 - this is what I bought several months ago.
Do not get me wrong, 34465A is an excellent meter. However, purely from GUI perspective DMM6500 is much more refined.
 
 
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Offline Electro Fan

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #28 on: June 06, 2019, 06:15:30 pm »
There has been some discussion about the feasibility of making simultaneous primary and secondary measurements with respect to relay switching and relay wear - but maybe there is a way around the relay issue....

At about 14:30-15:40 this indicates by being flexible on the selection of a compatible range for the secondary measurement (and I guess by definition the range for the primary measurement too) the relay switching might not be needed for dual measurements. 



Have users found that it is generally practical to find a suitable same-range so you can record both measurements simultaneously without invoking relay switching? 

When you record two measurements at the same time can you then see/review both measurements (with trendlines or table views) at the same time using just the front panel display?

On a related question, what's the longest I or V recording duration anyone has seen on the 6500?  minutes, hours, days?

Thanks, EF
 

Offline JxR

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #29 on: June 06, 2019, 06:20:13 pm »
Have users found that it is generally practical to find a suitable same-range so you can record both measurements simultaneously without invoking relay switching? 

Yes, you need to set the current from Auto to 1A or 3A ranges.  This will stop relay switching and was confirmed by Brad at Keithley, and tested personally by myself.  The voltage can be left on Auto range also.
« Last Edit: June 06, 2019, 06:23:21 pm by JxR »
 

Offline Electro Fan

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #30 on: June 06, 2019, 06:26:35 pm »
Have users found that it is generally practical to find a suitable same-range so you can record both measurements simultaneously without invoking relay switching? 

When you record two measurements at the same time can you then see/review both measurements (with trendlines or table views) at the same time using just the front panel display?

On a related question, what's the longest I or V recording duration anyone has seen on the 6500?  minutes, hours, days?

Thanks, EF

Yes, you need to set the current from Auto to 1A or 3A ranges.  This will stop relay switching and was confirmed by Brad at Keithley, and tested personally by myself.

Thanks for the super fast reply!  How about the 10A range? - can that also potentially also be aligned with the other measurement?

For example, if you have a power supply that runs at 24V and anywhere from 400mA to 4A, if we aren't too picky about the axis label spans on the graph, would it be feasible to measure both without the relays to see the trends of both over time, or is the notion of compatible ranges more theoretical than practical?  Thx again
 

Offline JxR

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #31 on: June 06, 2019, 06:37:07 pm »
How about the 10A range? - can that also potentially also be aligned with the other measurement?

For example, if you have a power supply that runs at 24V and anywhere from 400mA to 4A, if we aren't too picky about the axis label spans on the graph, would it be feasible to measure both without the relays to see the trends of both over time, or is the notion of compatible ranges more theoretical than practical?  Thx again

There is no relay switching using the rear panel 10A input, and with the current range set to 10A.  I just tested @20V with a load from 100mA to 3A.  No relay clicking occurred.  That is the best test I can do on short notice given the ranges you gave.  Basically my power supply is 2x channel 20V, but only can sink up to 3A.  While I could source 6A @ 20V, I don't have anything I can sink the current to get 4A.  Although given that I was on the 10A range on the DMM, I see no reason to assume that this behavior would change at 4A.
« Last Edit: June 06, 2019, 06:45:50 pm by JxR »
 

Offline JxR

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #32 on: June 06, 2019, 06:59:15 pm »
...would it be feasible to measure both without the relays to see the trends of both over time, or is the notion of compatible ranges more theoretical than practical?  Thx again

You can only do graphs and trends on the primary measurement.  What ever is set to the secondary measurement has no statistics available as far as I'm aware.  You can of course swap between the primary and secondary measurements at any time, but whatever is set to secondary only gives you the numerical value at that moment in time.

This behavior may be completely different if you had one of those scanner cards to use, but then you are certainly going to be using relays.  You may need to dig into the manual, or see if Brad on the big DMM6500 forum post  can answer your question.
« Last Edit: June 06, 2019, 07:08:24 pm by JxR »
 

Offline Electro Fan

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #33 on: June 06, 2019, 07:07:27 pm »
How about the 10A range? - can that also potentially also be aligned with the other measurement?

For example, if you have a power supply that runs at 24V and anywhere from 400mA to 4A, if we aren't too picky about the axis label spans on the graph, would it be feasible to measure both without the relays to see the trends of both over time, or is the notion of compatible ranges more theoretical than practical?  Thx again

There is no relay switching using the rear panel 10A input, and with the current range set to 10A.  I just tested @20V with a load from 100mA to 3A.  No relay clicking occurred.  That is the best test I can do on short notice given the ranges you gave.  Basically my power supply is 2x channel 20V, but only can sink up to 3A.  While I could source 6A @ 20V, I don't have anything I can sink the current to get 4A.  Although given that I was on the 10A range on the DMM, I see no reason to assume that this behavior would change at 4A.

So in general it seems not only feasible but practical to pick a range that should allow simultaneous V and I recordings with no relay switching.  Cool
(I think Keithley should make a video showing this for some plausible measurement values.)

Only 3 questions left :)

1. Can you see the V and I trendlines on the front panel display simultaneously?
(Keithley should put this in the video too.)

2. How long (minutes, hours, days) can you record V and I?
(Keithley should explain this in more clear detail in the spec sheet.)

3. How noisy really is the fan (how many dB at 1 meter distance?) :)
(Keithley should publish this spec if they haven't already.)

Thanks
 

Offline JxR

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #34 on: June 06, 2019, 07:21:59 pm »
1. Can you see the V and I trendlines on the front panel display simultaneously?
(Keithley should put this in the video too.)
No, only the primary measurement has graphs and trends.

2. How long (minutes, hours, days) can you record V and I?
(Keithley should explain this in more clear detail in the spec sheet.)
You can't record both simultaneously.  At least not without a scan card, and then you would be using relays. You could record indefinitely as far as I'm aware, but you might need to use KickStart, and set a sample rate that doesn't exceed the transfer rate over ethernet.  For the internal buffers, it would just depend on your settings and buffer sizes.  I expect you could make settings to record for days on the internal buffer only, but I have never tried it.  You can set measurement delays, count, and sample rate.  Just so you don't want a ridiculous sample rate you can probably stretch it out for a good long while.

3. How noisy really is the fan (how many dB at 1 meter distance?) :)
I have no equipment to tell you this.  I can hear it.  It is a pretty faint background hum.  It is low enough in volume that I could honestly forget its on, but loud enough to notice the difference when I turn it off.  It certainly doesn't bother me, or is it at a frequency that is irritating to me.  Anyways, I don't personally feel like the noise is a problem.  Although, I should clarify that a good portion of my adult life was spent working out of massive server rooms.  I'm pretty tolerant when it comes to background noises.

« Last Edit: June 06, 2019, 07:31:54 pm by JxR »
 

Offline Brad O

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #35 on: June 06, 2019, 07:23:42 pm »
...would it be feasible to measure both without the relays to see the trends of both over time, or is the notion of compatible ranges more theoretical than practical?  Thx again

You can only do graphs and trends on the primary measurement.  What ever is set to the secondary measurement has no statistics available as far as I'm aware.  You can of course swap between the primary and secondary measurements at any time, but whatever is set to secondary only gives you the numerical value at that moment in time.
You can graph the secondary measurement.  Secondary measurements are written to defbuffer2 (you must be on defbuffer1 to use secondary measurements) so you go to MENU > Graph > Data > Add defbuffer2 as a trace.  The Statistics swipe screen will only show stats on the active buffer (so the primary measurement), but you can see some buffer stats for the secondary measurement on the graph screen by switching traces.

How about the 10A range? - can that also potentially also be aligned with the other measurement?

For example, if you have a power supply that runs at 24V and anywhere from 400mA to 4A, if we aren't too picky about the axis label spans on the graph, would it be feasible to measure both without the relays to see the trends of both over time, or is the notion of compatible ranges more theoretical than practical?  Thx again

There is no relay switching using the rear panel 10A input, and with the current range set to 10A.  I just tested @20V with a load from 100mA to 3A.  No relay clicking occurred.  That is the best test I can do on short notice given the ranges you gave.  Basically my power supply is 2x channel 20V, but only can sink up to 3A.  While I could source 6A @ 20V, I don't have anything I can sink the current to get 4A.  Although given that I was on the 10A range on the DMM, I see no reason to assume that this behavior would change at 4A.
Correct, relay switching is dependent on the range selected, it doesn't care what the actual measurement is.

On a related question, what's the longest I or V recording duration anyone has seen on the 6500?  minutes, hours, days?
I've digitized at 1MS/s into a Continuous buffer for ~2 weeks.  That's the longest I've done but I believe others have data-logged for longer, at least with integrated measurements, not sure about digitizing.

1. Can you see the V and I trendlines on the front panel display simultaneously?
Yes, the front panel swipe screen will show the graph you've configured on the graph screen, you don't have any ability to edit the graph from the swipe screen though.

How long (minutes, hours, days) can you record V and I?
You're only limited by the size of your buffer and the speed of your measurements.  With a continuous buffer, you can theoretically record forever but you can't keep all the data as it's overwritten.  The KickStart software is a solution for very long term data-logging, writing a script to handle creating csv files automatically is another potential solution.

How noisy really is the fan (how many dB at 1 meter distance?)
This one I don't know, I don't have a dB-meter unfortunately.  It's one of the quieter instruments on my bench, but other people seem to think it's louder than other products in its class.  That's not really a spec we would publish because then we'd have to dB-meter all the instruments in an anechoic chamber.

(I think Keithley should make a video showing this for some plausible measurement values.)
Thank you for the ideas on the videos!  I will add them to my to-do list...
 
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Offline JxR

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #36 on: June 06, 2019, 07:30:03 pm »
You can graph the secondary measurement.  Secondary measurements are written to defbuffer2 (you must be on defbuffer1 to use secondary measurements) so you go to MENU > Graph > Data > Add defbuffer2 as a trace.  The Statistics swipe screen will only show stats on the active buffer (so the primary measurement), but you can see some buffer stats for the secondary measurement on the graph screen by switching traces.

Wow, that is awesome.  I learn something new about the device every time you post it seems.  Thanks Brad!
 
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Offline Electro Fan

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #37 on: June 06, 2019, 11:49:34 pm »
...would it be feasible to measure both without the relays to see the trends of both over time, or is the notion of compatible ranges more theoretical than practical?  Thx again

You can only do graphs and trends on the primary measurement.  What ever is set to the secondary measurement has no statistics available as far as I'm aware.  You can of course swap between the primary and secondary measurements at any time, but whatever is set to secondary only gives you the numerical value at that moment in time.
You can graph the secondary measurement.  Secondary measurements are written to defbuffer2 (you must be on defbuffer1 to use secondary measurements) so you go to MENU > Graph > Data > Add defbuffer2 as a trace.  The Statistics swipe screen will only show stats on the active buffer (so the primary measurement), but you can see some buffer stats for the secondary measurement on the graph screen by switching traces.

1. Can you see the V and I trendlines on the front panel display simultaneously?
Yes, the front panel swipe screen will show the graph you've configured on the graph screen, you don't have any ability to edit the graph from the swipe screen though.

Brad, thanks for all the info but I'm still not clear.... the answer to the first question sounds like the 6500 CANNOT simultaneously display V and I in one graph on the front panel display.  The answer to the second question sounds like maybe you CAN display the V and I trend lines simultaneously.

For the use case I have in mind I don't need to edit the graph, just see a graph showing both V and I over some time period of time.  Is this possible or not?  If it's not possible (which I'm guessing is the answer), I think it might be a good feature to add.  It would probably require the ability of the firmware to label time units on the X axis while labeling V units on one side of the graph and I units on the other side of the graph.  Thx
 

Offline JxR

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #38 on: June 07, 2019, 01:39:56 am »
It would probably require the ability of the firmware to label time units on the X axis while labeling V units on one side of the graph and I units on the other side of the graph.  Thx

Ok, I did try this out.  Both traces can be seen simultaneously.  Although, I do not see a scale for both traces simultaneously.  After you add both buffers to the data for the graph, you see both trend lines, but then you have to click which buffer scale shows up on the y-axis (along with its statistical data).  It is literally a single button press to change the y-axis between the two while watching the trend lines display, but there does not appear to be a way to show both scales on separate sides of the y-axis.

Of course since the data is there in both buffers, it would be simple enough to put a graph up in excel or some other program after retrieving the data.  I agree that it would be ideal to have both scales on separate sides of the y-axis.  Regardless it is pretty cool you can get the data from both measurements in the first place.

I personally would like to see this change, and I would like to be able to perform a secondary measurement in KickStart for the DMM app.  This functionality already exists in KickStart for the SMUs, so hopefully they will consider adding it.
« Last Edit: June 07, 2019, 01:45:09 am by JxR »
 

Offline Electro Fan

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #39 on: June 07, 2019, 02:24:06 am »
You can see the two lines traveling along next to each other so you can see trends - that’s a pretty good start.

If you could post an image from your test that would be cool. 

Below is a quote from hwj-d that describes my impression - the 7500/6500 is a new architecture and it might take a while to mature to meet all the likely use cases but it seems to be built on a very capable foundation.  Plus, Keithley seems pretty open to hear input and participate in discussion with users.  All good.

This dmm has a whole new approach as we know of the previous conventional type with measuring instruments of this type and offers far more possibilities. This gives rise to the problem of the gui developers of casting these into a mould which, on the one hand, must be consistent in terms of its technical possibilities and, on the other hand, must be as conclusive as possible from the user's point of view.

This results in two learning curves
 - for the developers to integrate these comprehensive new possibilities into the matching gui and api,
 - for the user to discover this new concept to make it usable for oneself by sorting out this mistakes despite the imperfect previous named path.

That is the compromise to be entered into, which we have to go together with such kind of measuring instruments.

We remember that gui and programming interfaces of measuring instruments of the previous conventional type have undergone decades of development on both sides.

Another compromise is the much cheaper technical implementation compared to his bigger brother DMM7510.
 
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Offline JxR

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #40 on: June 07, 2019, 02:59:59 am »
Ok, here you go.

The test is as follows:

Sweep voltage from 1-10V in 1V increments and 1s steps, then stop
Sweep current from 100mA-1A in 100mA increments every 0.1s (repeated)

In the bottom left corner where you see the name of the buffer is where I click to change between the two scales on the y-axis.  For the actual range of the scale on the y-axis this particular mode is called auto-independent.  There are other range scales you can pick, however whatever scaling system you use is shared between both measurements.  For instance I could turn auto-scaling off and set: minimum at 0V, and 1V increment.  That would then make the current scale the same (0A, 1A increment).  That would have obviously made the blue trace much smaller in scale.

« Last Edit: June 07, 2019, 03:43:35 am by JxR »
 
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Offline Electro Fan

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #41 on: June 07, 2019, 04:42:37 am »
Thanks for doing that and showing the results.

Seems like the core idea - dual measurement trend lines over the same timeframe on one graph with no relay switching - is very doable.  Might be nice if Keithley can provide some added user friendly control over axis increments/spans and (two sided) y axis labels but it looks like the 6500 is close as-is. 
 
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Offline hwj-d

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #42 on: June 07, 2019, 08:05:51 am »
...
Of course since the data is there in both buffers, it would be simple enough to put a graph up in excel or some other program after retrieving the data.  I agree that it would be ideal to have both scales on separate sides of the y-axis.  Regardless it is pretty cool you can get the data from both measurements in the first place.
...

Yes, or use the dmm's script/API to develop an app inside, to use it like a watt-meter or whatever.
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Offline Electro Fan

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #43 on: June 07, 2019, 03:50:12 pm »
Seems like in addition to being a great DMM, with TSP and Lua, the 6500 is a gateway drug that puts hardware enthusiasts on the path to becoming software enthusiasts :)
 
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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #44 on: June 11, 2019, 07:42:13 am »
We have a few 34465A and a DMM6500 in the office. Whenever I can measure something with the 34465A, I always choose that. UI is better, the package is smaller, I've been using it for years, trust it.

The DMM6500... Well it can measure really fast. UI is clunky, illogical, it does BSOD sometimes. Readings are not always visible. It is HUGE. But it is also a lot cheaper, and the high sample rate is useful, when it works.
TBH if I would spend my own money I would buy the Keithley.
 

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #45 on: August 11, 2019, 10:12:08 pm »
Does the DMM6500 can show one more digits, the 7.5th Digits in the STATISTICS screen like Keysight 34465A?

In Keysight 34465A, when enable the MATH -> Statistics function, the screen can display one more digits (the 7.5th Digits) in Average, like Average: +10.000,123 V, does DMM6500 can get the 7.5th Digits in the STATISTICS screen ?
 

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #46 on: August 11, 2019, 10:57:58 pm »
Does the DMM6500 can show one more digits, the 7.5th Digits in the STATISTICS screen like Keysight 34465A?

In Keysight 34465A, when enable the MATH -> Statistics function, the screen can display one more digits (the 7.5th Digits) in Average, like Average: +10.000,123 V, does DMM6500 can get the 7.5th Digits in the STATISTICS screen ?
Yes:
(your example, on both instruments only if DCV >=10V and <11V)
« Last Edit: August 11, 2019, 11:19:32 pm by hwj-d »
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Online Wintel

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #47 on: August 12, 2019, 12:18:09 am »
Does the DMM6500 can show one more digits, the 7.5th Digits in the STATISTICS screen like Keysight 34465A?

In Keysight 34465A, when enable the MATH -> Statistics function, the screen can display one more digits (the 7.5th Digits) in Average, like Average: +10.000,123 V, does DMM6500 can get the 7.5th Digits in the STATISTICS screen ?
Yes:
(your example, on both instruments only if DCV >=10V and <11V)
Thanks for your reply.

Would you mind to do one more test? If DCV > 10V, does DMM6500 also can show the 7.5 digits like 34461A?

Because I find some DMM6500 screen, if DCV >10, the Statistics -> Avg: is 6.5 digits only.



 

Offline AG7CK

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #48 on: August 12, 2019, 03:43:40 am »
Picture copied from post above:



On my meter (latest firmware), the average changes from 9.999999 to 10.00000 volt when I let a voltage source drift upwards, and reverts from 10.xxxxx to 9.xxxxxx when the voltage passes 10.0 volt downwards. This is because the print format is 7 digits with variable floating point. This must result from the programmer not knowing the instrument's specifications and it's intended use. No instrument designer would present a 6.5 digit DMM without a 7.5 digit average for 10 volt DC.

A clear sign of the programmer's total lack of knowledge or thinking, is the apparent resolution of Peak to Peak. Since one can assume that this number is a subtraction of Minimum from Maximum with a maximum resolution of 1 microvolt in this meter class' typical 20 bit or so ADC), it's apparent resolution in picovolts (4.884417 microvolt is 4,884,417 picovolt) is meaningless and looks embarrassing. Similar cases can be argued for all values presented.

This screen needs reprogramming.

 
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Offline AG7CK

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #49 on: August 12, 2019, 04:10:25 am »
Somone just sent me a message saying that a 6.5 digit DMM must have a 24 bit ADC. OK for me. I withdraw from any discussion. I guess I should have written "20 bit or more ADC".

Anyway: For Maximum = Minimum in the picture above (both presented with 10 microvolt resolution), it seems that Peak to Peak should prima facie be 0. As in: 7.12409 - 7.12409 = 0. Hence, for Peak to Peak to be 4 or 5 microvolt, there must be a microvolt hidden somewhere  :o ::) ??? That's all I wanted to say.

A nice read for bits, ENOBs, counts and resolution is: http://zone.ni.com/reference/en-XX/help/370384V-01/dmm/resolution_bits_digits/
 
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Online Wintel

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #50 on: August 12, 2019, 08:29:01 am »
Picture copied from post above:



On my meter (latest firmware), the average changes from 9.999999 to 10.00000 volt when I let a voltage source drift upwards, and reverts from 10.xxxxx to 9.xxxxxx when the voltage passes 10.0 volt downwards. This is because the print format is 7 digits with variable floating point. This must result from the programmer not knowing the instrument's specifications and it's intended use. No instrument designer would present a 6.5 digit DMM without a 7.5 digit average for 10 volt DC.

A clear sign of the programmer's total lack of knowledge or thinking, is the apparent resolution of Peak to Peak. Since one can assume that this number is a subtraction of Minimum from Maximum with a maximum resolution of 1 microvolt in this meter class' typical 20 bit or so ADC), it's apparent resolution in picovolts (4.884417 microvolt is 4,884,417 picovolt) is meaningless and looks embarrassing. Similar cases can be argued for all values presented.

This screen needs reprogramming.

Does DMM6500 have the same print format problem in the 1V and 100V range?
 

Offline hwj-d

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Re: Someone ask me to buy which dmm, Keysight 34465A or Keithley DMM6500
« Reply #51 on: August 12, 2019, 11:02:45 am »
...
On my meter (latest firmware), the average changes from 9.999999 to 10.00000 volt when I let a voltage source drift upwards, and reverts from 10.xxxxx to 9.xxxxxx when the voltage passes 10.0 volt downwards. This is because the print format is 7 digits with variable floating point. This must result from the programmer not knowing the instrument's specifications and it's intended use. No instrument designer would present a 6.5 digit DMM without a 7.5 digit average for 10 volt DC.

A clear sign of the programmer's total lack of knowledge or thinking, is the apparent resolution of Peak to Peak. Since one can assume that this number is a subtraction of Minimum from Maximum with a maximum resolution of 1 microvolt in this meter class' typical 20 bit or so ADC), it's apparent resolution in picovolts (4.884417 microvolt is 4,884,417 picovolt) is meaningless and looks embarrassing. Similar cases can be argued for all values presented.

This screen needs reprogramming.
The DMM has some issues not only with his GUI yes. We are all waiting for the overdue Firmwareupdate. For this, I specally posted the first screenshot. Have you seen it?

For my part, I can handle this innovative DMM in such a way that I get the information I need. My Keysight 34461A has other similar drawbacks in its GUI also, its capabilities, and its very own high temperature drift, which makes me prefer the much more flexible DMM6500 all the time.
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