[volt-nuts] Keithley 2001 vs HP 3457A multimeters / Any problems to watch out for on Keithley 2001?

[Dr. David Kirkby (Kirkby Microwave Ltd)]

I've got an HP 3457A (6.5 digit multimeter) which has served me well.  But
I see a Keithley 2001 7.5 digit meter on eBay

http://www.ebay.co.uk/itm/152113460174

which sort of tempted me as

1) It has an extra digit, I have not looked to see how much that extra
digit gains one. It would be nice to think the uncertainty is only 10% of
the 6.5 digit 3457A, but I very much doubt that's the case. I have not
looked at the specs closely.

2) I see it was a current model at Farnell selling at £4150 + 20% VAT =
£4980, so quite a bit of money. The 2001 is not a cheap meter.

3) It was £650 or "best offer".

4) The 3457A is a great meter, but is much older.

Anyway, my offer of £380 (GBP), was accepted, which is 7.6% of the current
cost of this new from Farnell. As I write, this is around $520 (USD), but
with the UK just voted to exit the EU, and the pound fallen quite a bit,
that US price may not be very representative. But it seems fairly cheap. I
can't see any Keithley 2001's sell for that low on eBay, unless they have
had faults.

Having made an offer, it been accepted, and me paid for it, now I decide to
see if it was a good or bad idea! I think one is compare the meters first,
then make a decision to buy or not, but I have done this the other way
around!

I'm interested in hearing any onions on

1) What's the 2001 like in general?

2) How does it compare to the 3457A? Have I made  big mistake in paying
£380 (GBP) to buy a 2001, when I already have a HP 3457A?

3) Are there any specific advantages of the 3457A which would make it
desirable to keep both units, rather than sell the 3457A, which is my
intention?

4) I assume the "Revision A06" refers to some hardware/firmware releases.
Does that give any idea of how old this is?

5) I note from a Google there are some revision B07's, which I am assuming
are later. Does anyone know if there are any significant issues on an A06,
or whether it can be upgraded - is it just firmware?

*6) Most importantly, are there any specific faults that occur on the 2001,
which I might be able to spot doing procedures X, Y and Z, but which are
not blindingly obvious? *

Obviously when this arrives, I will attempt to do any self-tests I can find
in the manual. I don't have any "standard" good enough to check the
accuracy, but a comparison with the 3457A should show up any really bad
faults - or at least leave me wondering what meter to trust! I will be like
the man with two clocks! The 3457A has not bee calibrated for ages.

I will get a quote from Tektronix for calibration. Hopefully that will show
up any faults.

BTW, it does seem the 8.5 digit meters (Agilent 3458A, Keithley 2002) hold
their value far more than the 7.5 digit ones. I guess the cheaper 7.5 digit
ones are sold in much larger quantities.


Dave