3458A - black edition

[Le_Bassiste]

well, with all your concerns, all is not lost. just trade it in for a 20% discount. 
-scnr, that gave me a good chuckle!

(approximate) translation: "trade-in your old precision multimeter for a new fluke reference multimeter 8588A or 8558A and save up to 20%!"

[Wolfgang]

Yeah, why not ? Slightly better specs, modern LCD, USB/LAN interfaces, and a 3458 compatibility mode.
Fluke has also been selling reference multimeters or decades. How much would this one cost ? (3/4ppm version).

[TiN]

Just a status update about 3458A Black review progress. I have collected lots of data and had nice photoshoot, and currently busy checking data and doing additional tests on my own 3458A's and other meters used in comparison. Black meter is back at Keysight now, and I plan to release review this month, including nice juicy thread in EEVBlog Metrology.

Overall I'm happy with Keysight teamwork on this, very pleasant experience indeed. Not every day you get to try out brand new instrument, so some credits go to EEVBlog voltnut community too.

Want to make it nice and comprehensive with Python test apps used in performance verification, good plots to show highlights. All that takes time to do right. I have my primary 10V and 10 kOhm standards out for traceable calibration at the moment to confirm absolute accuracy data I've collected.

If you want to have short summary : everything you know about original 3458A is also valid for new one. It works like 3458, feels like 3458, so it is same 3458A. That applies to performance as well. Unit I had in test was STD production instrument, manufactured in December 2019. Noise, tempco and other secondary performance results show that it is average 3458A, inside of the Keysight specifications. This particular unit is not a replacement to golden special 3458A's that some of us have, we might want to wait for 9.5-digit DMM for that  .
 

[Dr. Frank]

This particular unit is not a replacement to golden special 3458A's that some of us have, we might want to wait for 9.5-digit DMM for that  .

For 9 1/2 digits, you need a less noisy LTZ1000 / LTFLU / zener  replacement.

Frank

[notfaded1]

For 9 1/2 digits, you need a less noisy LTZ1000 / LTFLU / zener  replacement.

Frank

This is what amazes me... with all our new technology we still can't seem to build a better mousetrap.  We can build quantum computers but still can't seem to build a better zener?

B

[Dr. Frank]

For 9 1/2 digits, you need a less noisy LTZ1000 / LTFLU / zener  replacement.

Frank

This is what amazes me... with all our new technology we still can't seem to build a better mousetrap.  We can build quantum computers but still can't seem to build a better zener?

B

Nope. The zener diode will ALWAYS be that noisy.
You need a replacement for that technology, i.e. a voltage reference which is NOT based on the zener effect.
Frank

[Kleinstein]

The LTZ1000 zener is not perfect in a sense that it can not be made better. It may be one of the best zeners currently available, but chances are it can be done better: some of the Chinese DW232 seem to be lower noise, the unheated TC is not that low as with the LTFLU and some of the bare die pictures show luminescence (thus likely some surface contribution and not a perfect buried zener). Chances are the noise of the LTFLU may be a little lower.  If really needed one could use multiple reference together. For a real reference meter a combination of something like 2 or 3 reference would be a good idea anyway to get at least a cross check.

Anyway, except for metrology, there is a very limited need for such a very high resolution / low noise. There is limited need for a noise level much lower than the DUT.
The 3458 is not that special for it's reference or noise. The really special point is the linearity, and there are not that many meters that only come close. Noise wise the 34470 is not that different, but the linearity is a different class.

[niner_007]

Yeah, why not ? Slightly better specs, modern LCD, USB/LAN interfaces, and a 3458 compatibility mode.
Fluke has also been selling reference multimeters or decades. How much would this one cost ? (3/4ppm version).

Because you'd be losing at least some $5000? Look at the ad, it has the new 3458A in there as well not just some 30 year old random unit.

[Henrik_V]

For 9 1/2 digits, you need a less noisy LTZ1000 / LTFLU / zener  replacement.

This is what amazes me... with all our new technology we still can't seem to build a better mousetrap.  We can build quantum computers but still can't seem to build a better zener?

Wait.. there are some better units... involves liquid He, a HF source ..
drawback: it's no zener anymore.. and you have your perfect 10V (or n times xV) in a cold bottle .. and you need to get it out to the heat   .. and you don't want eddy currents in the bottle circulating forever.. and ... and .. 

[Wolfgang]

What you could think of is *parallelizing* references for low noise. 10 chips ca. 1/3rd of the noise.

[MiDi]

For 9 1/2 digits, you need a less noisy LTZ1000 / LTFLU / zener  replacement.

This is what amazes me... with all our new technology we still can't seem to build a better mousetrap.  We can build quantum computers but still can't seem to build a better zener?

Wait.. there are some better units... involves liquid He, a HF source ..
drawback: it's no zener anymore.. and you have your perfect 10V (or n times xV) in a cold bottle .. and you need to get it out to the heat   .. and you don't want eddy currents in the bottle circulating forever.. and ... and ..

Meh, ancient technology back from the 80s everywhere...
Essentially no improvements since more than 30 years...
Not even miniaturisation and better energy efficiency...
Still waiting for the cheap pocket quantum standards...

[Wolfgang]

Spooky green VFDs and GPIB rulez !! Retro black is the new smart. The fanboys objected any change. 

[SilverSolder]

Spooky green VFDs and GPIB rulez !! Retro black is the new smart. The fanboys objected any change. 

It is OK to keep the old meter the same, for all the reasons that people have given (compatibility with existing setups, certifications, etc. etc.).

What we need is a NEW meter, one that adds another order of magnitude of performance! 

[Wolfgang]

IMHO, no one insisted on VFD and GPIB only. They insisted on upward compatibility, which is fully OK.
The rest is marketing blabla and the intention to get away from the ROHS issue with the minimum investment possible. 

[bsdphk]

"IMHO, no one insisted on VFD and GPIB only."

You could change the VFD to any other display technology you want, glyph for glyph.  The display has its own controller so that would not require any software changes, but doing so would not sell a single extra meter.

Changing what is displayed would require a significant investment in software modifications, and would probably not sell more than ten or twenty extra meters for them.

Changing the external interfaces to the outboard processor, would require a major investment in software, it is not "just" in any sense of that word, and it would probably not seel more than an extra ten or twenty meters either.

If Keysight wanted to do any of those things, the only sensible way to go about it is to get the RoHS meter out there to keep the revenue stream going, and then introduce a B model later, which has the same in-guard boards, but a different out-guard controller, frontpanel and backpanel.

Depending on the production and long term experience with the RoHS in-guard boards, and in particular actual customer feedback, (as opposed to various volt-nuts without purchasing budgets in some quaint but not revenue generating forum), they might also update the specifications at that time.

I do not expect that to happen.

(But again:  If Keysight needs somebody with the necessary code-archaeology skills, I'm available :-)

[Wolfgang]

See it as you like,

there is no excuse for boutique vintage parts like VFDs and antique interfaces in 2020 except short-sighted profit maximisation.
Of course they can do better than that, after 30 years !!

I think a company being lucky enough to have a succesful product in the market for 30 years needs not to be pitied if a major redesign is due. The ROI period of the 3458A is very long over, so come on, start moving.

[MadTux]

Wonder how many of those LCD DMMs end up smashed during shipping/rough handling/accident with soldering iron etc. in the next 20 years.
Graphical LCD also needs fancy display controller, usually with integrated flash memory. As soon as the flash cells leak out, you have an expensive brick, if the firmware is nowhere available.

I don't need any graphical interface on any DMM/SMU (can be done remotely, if needed), simple LED display (like in HP3456A) is enough (alphanumerical such in Keithley 236/237/238 is especially nice). Robust, lasts forever and can be
replaced easily. 

VFD is nice when new, dimming at old age sucks however. Also fails more often than LED, is more fragile and usually needs difficult to get parts for high voltage drive signals.

[SilverSolder]

See it as you like,

there is no excuse for boutique vintage parts like VFDs and antique interfaces in 2020 except short-sighted profit maximisation.
Of course they can do better than that, after 30 years !!

I think a company being lucky enough to have a succesful product in the market for 30 years needs not to be pitied if a major redesign is due. The ROI period of the 3458A is very long over, so come on, start moving.

Sometimes, simple is better.  GPIB can still do things that more modern interfaces can't.  For example, trigger multiple instruments at exactly the same time?  ... the most important feature is probably being able to play well with other instruments that all have GPIB... 

[Wolfgang]

GPIB still has a few merits, but is simply dying out in the new instrument generation.

I think the reason why some people are willing to accept all the retro user interfaces and missing functionality is that they dont work with this as a lab instrument, but as an automated test tool in production or QA. Nobody will ever look at the output of the meter, and nobody will press any keys, all runs under remote control.

I need something like this in lab work changing every day, and therefore I want a compatible look and feel as my other meters (e.g., 34470A) and Keysight benchtop instruments.

A smart solution would be a PXI-based box for the remote control people and something really up to date for the lab guys.

[CalMachine]

GPIB still has a few merits, but is simply dying out in the new instrument generation.

I think the reason why some people are willing to accept all the retro user interfaces and missing functionality is that they dont work with this as a lab instrument, but as an automated test tool in production or QA. Nobody will ever look at the output of the meter, and nobody will press any keys, all runs under remote control.

I need something like this in lab work changing every day, and therefore I want a compatible look and feel as my other meters (e.g., 34470A) and Keysight benchtop instruments.

A smart solution would be a PXI-based box for the remote control people and something really up to date for the lab guys.

I think you are way off base and as someone who used 3458a in a metrology lab for years, I would vomit if they released PXI version.  In my experience, PXI bus is nothing but a hassle. 

I, for one, am glad they kept the VFD and GPIB interface.  Replacement parts are relatively cheap and readily available.  I don't foresee your wanted LCD display lasting 30+ years as the original 3458a hardware has... and when that display goes out?  Better get ready to fork over $$$$$.

[bsdphk]

"I think the reason why some people are willing to accept all the retro user interfaces and missing functionality is that they dont work with this as a lab instrument, but as an automated test tool in production or QA."

And you know what ?

Those "some people" make up 99% of the HP3458A sales.

[Wolfgang]

GPIB still has a few merits, but is simply dying out in the new instrument generation.

I think the reason why some people are willing to accept all the retro user interfaces and missing functionality is that they dont work with this as a lab instrument, but as an automated test tool in production or QA. Nobody will ever look at the output of the meter, and nobody will press any keys, all runs under remote control.

I need something like this in lab work changing every day, and therefore I want a compatible look and feel as my other meters (e.g., 34470A) and Keysight benchtop instruments.

A smart solution would be a PXI-based box for the remote control people and something really up to date for the lab guys.

I think you are way off base and as someone who used 3458a in a metrology lab for years, I would vomit if they released PXI version.  In my experience, PXI bus is nothing but a hassle. 

I, for one, am glad they kept the VFD and GPIB interface.  Replacement parts are relatively cheap and readily available.  I don't foresee your wanted LCD display lasting 30+ years as the original 3458a hardware has... and when that display goes out?  Better get ready to fork over $$$$$.

I dont think VFDs have such a good reputation for longevity or reliability. Also on the 34401A the display has been a comon weak spot.
VFDs are boutique parts even today. Readiliy available in 20 years to come to repair todays 3458As ? Rather not. 

[Wolfgang]

"I think the reason why some people are willing to accept all the retro user interfaces and missing functionality is that they dont work with this as a lab instrument, but as an automated test tool in production or QA."

And you know what ?

Those "some people" make up 99% of the HP3458A sales.

As the comments in this forum show, your 99% are probably an exaggeration. My guess is 60 to 70%.

[SilverSolder]

GPIB still has a few merits, but is simply dying out in the new instrument generation.

I think the reason why some people are willing to accept all the retro user interfaces and missing functionality is that they dont work with this as a lab instrument, but as an automated test tool in production or QA. Nobody will ever look at the output of the meter, and nobody will press any keys, all runs under remote control.

I need something like this in lab work changing every day, and therefore I want a compatible look and feel as my other meters (e.g., 34470A) and Keysight benchtop instruments.

A smart solution would be a PXI-based box for the remote control people and something really up to date for the lab guys.

I think you are way off base and as someone who used 3458a in a metrology lab for years, I would vomit if they released PXI version.  In my experience, PXI bus is nothing but a hassle. 

I, for one, am glad they kept the VFD and GPIB interface.  Replacement parts are relatively cheap and readily available.  I don't foresee your wanted LCD display lasting 30+ years as the original 3458a hardware has... and when that display goes out?  Better get ready to fork over $$$$$.

I dont think VFDs have such a good reputation for longevity or reliability. Also on the 34401A the display has been a comon weak spot.
VFDs are boutique parts even today. Readiliy available in 20 years to come to repair todays 3458As ? Rather not. 

VFDs can be reliable, if done right.  I have a couple of 1970s era HP 59304A GPIB displays that use some type of gas discharge technology.  When I got them, they showed every sign of having been run constantly on for 30 or 40 years...  but simply cleaning the film of dust from the inside of the transparent red front panel filter/lens made the displays as bright as new.  Nothing needed fixing...  just cleaning!  Even the three bulb indicators still worked...

[TiN]

I rather prefer 3458A's easy interface and front controls, which are very quick and easy to use after you program hotkeys to typical operations, than modern flashy LCDs which are mostly horrible for view angles, have menus upon menus inside the menus and require grunty processors, switching power supplies and other drawbacks in instrument. Sure, LCD is great to have for general every day bench, or on the scope, but for calibration/automated system DMMs it is not functional importance.

And "modern look" or "antique controls" or "vintage feel" or "smooth multi-zone touchscreen" are not very relevant when you paying $11k+ for a professional tool for a job to do.