[time-nuts] Volt-nuts cooperation?
holrum at hotmail.com
Sat Jun 20 18:04:35 EDT 2009
The 3458A has two types of calibrations. The first is done every year or two using the external references. The other is an internal self calibration which you should run every day or two. This is pretty much standard for every high res meter on the market today (except most want you to send it to the external cal lab every six months)
The 3458A is probably the best meter on the market. It seems like multimeters pretty much stopped evolving with this unit. Basically 8.5 digits seems to be the practical limit of resolution that you can extract from silicon devices. 8.5 digit meters have been available for around over 20 years now. Nobody seems to have come out with anything better in the last 20+ years.
As far as spending $4-5K for a 3458A, if you are patient and a little lucky you can score one for half that. I bought one for under $1500 (but sold it after I was made an offer I could not refuse). My latest one cost $2500. There is one on Ebay right now that opens at $1600. I suspect it will sell for under $2800.
I am a little confused as to your needs. On the one hand you feel the hp3458A is
a fine instrument only needing “CAL” every 2 years, yet you then say it needed to
be “CAL’d” every 2 days to stay repeatable. That does not sound very encouraging
and is indicative of other problems.
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