New Keithley DMM6500 and now DAQ6510

[analogRF]

yes I did many many attempts and it gives that 2224 error every time
and if there is a USB stick in it, it saves screendump. and USB stick is full of other stuff...

[RBBVNL9]

yes I did many many attempts and it gives that 2224 error every time
and if there is a USB stick in it, it saves screendump. and USB stick is full of other stuff...

OK, I see. So it is unresolved, for the time being, why some experience this crash, and others do not...

[E-Design]

and no transformer annoyance or excessive fan noise either. Transformer is really silent and fan is normal, no louder than my agilent multimeter

Regarding the fan noise: Did someone already a DIY improvement? I feel a bit disappointed with the noise level. For my device I measure 52 dBA close to the fan and 40 dBA appox. 0.5 m away. Blocking only the inlet area increases the temperature inside the device and some drift in the measurements becomes visible.

Thank you!

Simon

Close to the fan isn't a realistic use case for the measurement. But 40dBA at 0.5m seems a bit on the high side,  but not excessive.

If you are willing to void your warranty (as many people are) -- there are things that can be done to improve the audible noise. Some were mentioned earlier in this thread...

[macaba]

I put together a precision PWM DAC and automated a test with 0.5V steps from -9.5V to +9.5V.
DMM6500 set to 1NPLC, high impedance input, autozero enabled.
Per step; 80 seconds to allow the PWM DAC output to settle, approximately 1 minute of samples acquired and averaged to give a single value for the chart.

Linearity chart is attached.

I'm mostly certain that the majority of the error shown in the chart originates from the DMM6500 rather than the PWM DAC.

(The error in a PWM DAC, due to switch resistance mismatch [0.71 ohms in my case], is a smooth inverse x^2 curve with max error around the midpoint which I have corrected in the DAC firmware, not at all visible as even the slightest x^2 curve trend in the chart so I'm comfortable that this source of error is eliminated)

It's comparable to the typical factory test data spreadsheet given earlier in this thread and it's well within tolerance, which is pleasing.

[Simi-DT]

I did some tests with a funnel over the inlet openings (left side with the fan). This helps to make the noise more pleasant for me, but not really silent. The unpleasant spikes at e.g. approx. 337 Hz disapper. Temperature wise it is not a perfect solution (plus 2 or 3 K) and need some improvements. I did not want to open the case in the first years, so some external sound blocking measures are welcome.

Simon

[The Bootloader]

Pressing HOME+ENTER the first time without a USB flash drive creates an error in the log.
Doing it again creates a BSoD (see attached photo)

I can however do a screenshot multiple time in a row, with a USB drive inserted, without triggering a crash.

For good measure I have filed a ticket with Keithley referring to this thread.

[The Bootloader]

I did some tests with a funnel over the inlet openings (left side with the fan). This helps to make the noise more pleasant for me, but not really silent. The unpleasant spikes at e.g. approx. 337 Hz disapper. Temperature wise it is not a perfect solution (plus 2 or 3 K) and need some improvements. I did not want to open the case in the first years, so some external sound blocking measures are welcome.

What equipment are you using to do these fancy noise graphs ? Are they calibrated ? Super nice !

[Simi-DT]

I did some tests with a funnel over the inlet openings (left side with the fan). This helps to make the noise more pleasant for me, but not really silent. The unpleasant spikes at e.g. approx. 337 Hz disapper. Temperature wise it is not a perfect solution (plus 2 or 3 K) and need some improvements. I did not want to open the case in the first years, so some external sound blocking measures are welcome.

What equipment are you using to do these fancy noise graphs ? Are they calibrated ? Super nice !

Hello!

The graphs were processed with an external sound card with mic preamp (TASCAM UH-7000), a mic with less noise (Rode NT1-A) and the freeware REW Room EQ Wizard from John Mulcahy. Only DIY calibration. May be 2 or 3 dB out of real levels, but not that critical for this case - looking for peaks, harmonics and differences.

Simon

[analogRF]

is there any chance that one day FFT and THD will be added to the firmware?
all the hardware is there, it's just a matter of programming

[E-Design]

is there any chance that one day FFT and THD will be added to the firmware?
all the hardware is there, it's just a matter of programming

Why YES there is a possibility.
IIRC, there are apps created already that do these features.. (I think)

[analogRF]

is there any chance that one day FFT and THD will be added to the firmware?
all the hardware is there, it's just a matter of programming

Why YES there is a possibility.
IIRC, there are apps created already that do these features.. (I think)

well, with 1MS/sec speed, I think there are many potential applications (at least in power and audio electronics) for having spectrum analysis (FFT) and THD measurement (and possibly even other freq domain measurements).

So, is it possible that Keithley will consider adding those features in the future?

since I am new to this (just got mine last week), I have not found any apps doing these stuff yet. Can somebody confirm if such apps exist and where they can be found?

[macaba]

Please can anyone explain why I'm seeing a step change in voltage reading when I switch settings (using config list & triggerflow model)?

Attached are two examples. Meter starts in 1 NPLC mode, runs for 10 seconds, then switches to either 10 NPLC or x10 filter for 10 seconds.

[macaba]

Looks like I'm able to resolve it with Line Sync = on. The noise sensitivity of this meter is turning out to be the biggest flaw especially as in this case the source impedance is 50 ohms (DAC set to ~0V). 

See attached screenshot. Looks like line sync isn't 100% effective judging by the occasional spike in the first half.

[Kleinstein]

In which mode and range are the measurements done ?
When using a non AZ mode, there may be new zero phase when changing the speed.

[E-Design]

Yes changing settings (like NPLC) will flush the backgrounds..

[E-Design]

is there any chance that one day FFT and THD will be added to the firmware?
all the hardware is there, it's just a matter of programming

Why YES there is a possibility.
IIRC, there are apps created already that do these features.. (I think)

well, with 1MS/sec speed, I think there are many potential applications (at least in power and audio electronics) for having spectrum analysis (FFT) and THD measurement (and possibly even other freq domain measurements).

So, is it possible that Keithley will consider adding those features in the future?

since I am new to this (just got mine last week), I have not found any apps doing these stuff yet. Can somebody confirm if such apps exist and where they can be found?

Well, if they were released, I think they would be here

https://www.tek.com/keithley/tsp-applications-for-touch-test-invent-models

But alas, I dont see them. I do recall them being worked on so I will have to check on that when I return to the office.

[analogRF]

is there any chance that one day FFT and THD will be added to the firmware?
all the hardware is there, it's just a matter of programming

Why YES there is a possibility.
IIRC, there are apps created already that do these features.. (I think)

well, with 1MS/sec speed, I think there are many potential applications (at least in power and audio electronics) for having spectrum analysis (FFT) and THD measurement (and possibly even other freq domain measurements).

So, is it possible that Keithley will consider adding those features in the future?

since I am new to this (just got mine last week), I have not found any apps doing these stuff yet. Can somebody confirm if such apps exist and where they can be found?

Well, if they were released, I think they would be here

https://www.tek.com/keithley/tsp-applications-for-touch-test-invent-models

But alas, I dont see them. I do recall them being worked on so I will have to check on that when I return to the office.

thanks, that would be awesome.

[The Bootloader]

We miss having Keithley support staff in this product thread like Siglent or R&S are doing in the other threads about their products.
There is a lot of relevant input here from their customers that could be useful. Many ideas going to waste because noone is looking at them

Personally I really wish a mini oscilloscope-like interface in the Digi modes with the high sample rate. I want to see things like V/div and ms/div, not sample counts for instance

[analogRF]

We miss having Keithley support staff in this product thread like Siglent or R&S are doing in the other threads about their products.
There is a lot of relevant input here from their customers that could be useful. Many ideas going to waste because noone is looking at them

Personally I really wish a mini oscilloscope-like interface in the Digi modes with the high sample rate. I want to see things like V/div and ms/div, not sample counts for instance

there is at least one of the Keithley engineers very active as far as I know. Just take a look at the previous couple of pages...

[KedasProbe]

If you want to have a bit of a comparison for Hum (50Hz/60Hz and Multiples)
I put my Android smartphone on top of the DMM6500 and let the Spectroid app run.

50Hz and 60Hz is probably too low for good measurement but 100Hz isn't a problem.
I got Silence, Hum only and Hum+Fan noise.

I must say that I do think it's not as loud as it was when I bought it so it's probably not very stable either meaning it could pas the production test and then get much worse/better after.
(normally you would expect it gets worse over time)

[The Bootloader]

Hi !

I made a small video at the request of one of my viewer, who was asking for information about the dual measurement mode of the DMM6500 :


Hoping some of you find this useful. Enjoy !

[KedasProbe]

I think you forgot to mention the limitation that the meter will not work within specifications when you combine Voltage and Current. (there can be a big error depending on your settings)

[RBBVNL9]

@KedasProbe

I think you forgot to mention the limitation that the meter will not work within specifications when you combine Voltage and Current. (there can be a big error depending on your settings)

Interesting! I might have experienced this, unknowingly, when I was getting measurements that seems to be plainly wrong...

Yan you elaborate please?

[Kleinstein]

The principle problem is the shared common for the current and voltage reading. There is always the resistance of the plug, that will add an error to the voltage reading.

In addition it looks like there is some extra resistance internal to the DMM6500 that adds to this. So the common ground point is not at the plug, but more like on the low side of the smallest shunt resistor. This is the natural choice when using a 4 wire shunt. The resistance of the cable would than add to the troublesome part.

So when there is a significant current flow, don't expect highest accuracy for the voltage reading.

[KedasProbe]

The Voltage & Current range combinations without relay activity are DC 1A/3A and 10A combined to a DC voltage range (excluding the 1000V range)

These are about the errors you can expect: (at least on my device)
Front 3A: -37.9 mV/A
Back 3A: -59.6 mV/A
Back 10A: -1.11 mV/A
You have to subtract or add it to the displayed value depending on your current direction (not tested but assumed)

So using the back 10A is your best option.

Edit:
You also want to avoid the 100V range because then you get an extra -2.45 V bonus error. (no I did not forget the 'm')
https://forum.tek.com/viewtopic.php?f=617&t=141896&sid=3146fff8749d5978945e90c5c2ab204c