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Fluke 8845A experience/opinions ?

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Soertier:
I have the chance to buy a Fluke 8845A at a good price. Now the question is what is the reliability of these instruments and how much they drift per year. I would actually buy a HP Agilent 34401A, however I really need to measure high currents at low voltages (3V-4V) and the 34401A is poor in that regard due to it's high burden voltage.

I read quite some criticism on this forum regrading the 8845A/8846A boot times and OS and the banana plugs being brittle.

Are there any persons from cal labs around here which have some facts on the 8845A? Does the instrument stay in spec well (voltage resistance) compared to 34401A?
Or are any users of the 8845A that frequently check how well stays in spec?

nukie:
Three of my 34401A (year 1992, 1995, 1998) did not drift much. I bought all of them used, burn in for 4000 hours then sent it in for calibration. They were bought separately many ages ago. They stay in spec till today. I use three LTZ1000 powered as my references. They are also burned in for 4000 hours then voltage verified at a lab.

If you want absolute stability and very little long term drift, get the Keithley 2000. I have one used and it stayed true to the last digit for the pass 5 years.

The slow boot up of the 8845A would not be a problem if you run a lab most equipment would be on for long hours. 8845A is a newer device compared to the 34401A. I prefer Agilent products the vfd module is plenty for $100 if it dims after a few years.

tapatalk

Kibi:
Not a 8845A, but the same family I suppose, my 8840A which is very old is spot on accuracy wise.
I did a tear down and repair of it recently. Details on this thread.

https://www.eevblog.com/forum/reviews/fluke-8840a-teardown-and-repair/

robrenz:
Rant mode on

As a very happy 8846A owner I don't get where the 15 second boot time has any relevance on a meter that has a specified 1 hour warm up time for stated accuracy :-//
Trend plot shows the meter is fully stable in 30 Min's.

Rant mode off

Soertier:

--- Quote from: nukie on December 07, 2012, 01:01:11 pm ---
If you want absolute stability and very little long term drift, get the Keithley 2000. I have one used and it stayed true to the last digit for the pass 5 years.


--- End quote ---

Keithely 2000 is in the same boat with 34401A when it comes to current measuremnts due to high burden voltage and low voltage circuits (3A-4V) at high currents ( 2A-4A) will be result in useless readings.
I have heard that the Keithley 2000's stay well in spec (what I am looking for), however I see most of them sold as defect of partially defect which is not enouraging at all for me.

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