3458A and ADC drift

[Kleinstein]

In industry there is little need for 8 digit resolution. The big point of the 3458 there is more in getting good resolution (5-7 digits) fast. However in this area some modern meters like the Keithley DMM7510 can be nearly as good and an optional scanner is a big plus.
The real need for 8.5 digits is essentially only in metrology, e.g. to check other meters / calibrations and similar. So it's a niche market and it's much about reputation.

At least from the specs the 2 new Fluke 8.5 digit meters seem much lower noise than before. So this may very well be more than just a simple slight upgrade of the old Datron ADC.

[Dr. Frank]

Well, the upcoming '3458A - Black Edition' will probably contain nearly the same schematics inside as the latest version, but most of its components will be transferred to SMD and RoHS technology only, therefore smaller PCBs, plus replacement of several terminated parts. Hopefully, they did not touch the magic inside the original layout..

Everything might be compatible to the old instruments, as HP /agilent already did that during the last 30 years.

Maybe there will be an improved specification, as KS surely has to go through a new validation / qualification process, which  might be the reason, why the updated instrument is not yet available.

I also assume, there will be no firmware change. It'll have the same GPIB interface only... HP did also not want to touch the rock solid firmware of the HP48 calculators, later on.

KS simply does not have these 'eggheads' anymore, who either left the company (towards Keithley), retired, or already passed away (poor Mr. Swerlein).

Some remainders of the original team just designed the 34465A/470A, but the knowledge about that 3458A magic surely passed away also, and I really doubt that this had been documented well enough.

Although there would be some details to be improved, like this mistreated LTZ1000 reference, the thermal handling, the poor Ohm mode, or some components which have too big a drift.. but why change a near perfect design, especially this unsurpassed A/D converter, for no real advantage, no real perspective for noteworthy improvement, due to probable physical limitations?

Frank

[iMo]

.. but why change a near perfect design..

Why ElonM and his SpaceX does not use the Sojuz or Proton rockets then? 

[niner_007]

Proton and Soyuz rockets are far from perfection

[Zucca]

Well, the upcoming '3458A - Black Edition'

we should start a separate thread only about the Beast Edition 3458A. Right now we have some informations spreaded in different places.

[Gandalf_Sr]

.. but why change a near perfect design..

Why ElonM and his SpaceX does not use the Sojuz or Proton rockets then? 

Elon Musk has ALL the key stuff designed and built in-house; from fuel tanks to triple-redundant avionics.  For one thing, buying rockets from Russia would seem like a very dodgy proposition for a company that's contracted to deliver secret stuff into space for the US government and anyway, reliance on an external contractor is always a risk that you will struggle to contain.

I truly admire Musk for what he's achieved but I'm not sure I'd like to work for him.

[iMo]

FYI - my question above was rather a rhetorical one

[niner_007]

FYI - my question above was rather a rhetorical one

yes we know, the SpaceX is Keysight here

[maat]

Well, save the date, 1st of December:
https://www.meilhaus.de/en/3458a.htm

[iMo]

Any teardown seen?

[niner_007]

Well, save the date, 1st of December:
https://www.meilhaus.de/en/3458a.htm

The king is dead, long live the king :-) The beast is back.

[rogerymw]

Hello Everybody,

I just testing an old "HP" Logo 3458A, the CAL? 72 data as attachment.

A is time : Mins
B is Temp? value
C is CAL? 72 value


Is that the drift too high?

[Kleinstein]

I just testing an old "HP" Logo 3458A, the CAL? 72 data as attachment.

A is time : Mins
B is Temp? value
C is CAL? 72 value

Is that the drift too high?

It depends on the unit for the times scale:
For this is time in seconds the measurement is too short. If this is time in hours or days  , the dirft would be OK. For a time in minuts the drift is too high. It could still be just a settling effect after longer not using the meter - in this case it may still stabilze and need a little more time to tell.

[rogerymw]

off about a month before.

how about yours? for how long it will drift less?

Thanks!