[volt-nuts] HP 3458A cal

[Dick Moore]

@Greg Burnett -- thanks so much for that info -- I certainly did not know that, and the folks at Loveland never articulated that difference either. What a difference. I really appreciate your information. Now, to find the rest of the cash somewhere.....

I'm assuming the STE9000 cal is automated -- do you know whether they use a Fluke 5720 or 21?

Dick Moore


On Aug 26, 2010, at 5:00 AM, volt-nuts-request at febo.com wrote:

> Message: 3
> Date: Wed, 25 Aug 2010 14:34:34 -0600
> From: "Greg Burnett" <gbusg at comcast.net>
> Subject: Re: [volt-nuts] volt-nuts Digest, Vol 12, Issue 11 (HP 3458A
> 	Cal)
> To: "Discussion of precise voltage measurement" <volt-nuts at febo.com>
> Message-ID: <006001cb4494$ef0df8f0$6501a8c0 at gb02>
> Content-Type: text/plain;	charset="iso-8859-1"
> 
> Hi Dick,
> 
> Something in your post caught my eye. Are you aware that, although performed at Loveland, Agilent's $500 cal is *not* performed in their Standards Laboratory. In order to receive their Standards Lab Cal, you have to specifically ask for that, and the cost is approximately $1350.
> 
> Basically their $500 cal is a STE9000 "Service Center" cal, although it's now performed geographically at Loveland. I'm the one who calculated the STE9000 version MU approximately 20 years ago. ...And I tweaked the procedure a bit for a little better metrology. The STE9000 version calibration for 3458A was developed for field calibration, hence its inferiority to the Standards Lab cal.
> 
> Having intimately evaluated the two versions of 3458A cal, I would briefly summarize the situation as follows:
> 
> If you only need a "go / no go" status for your 3458A, then the STE9000 cal might be sufficient for you. But if you wish to actually use the supplied test data (that's supplied along with the calibration), then the STE9000 cal is insufficient and you instead want the Standards Lab cal.
> 
> Put another way, if you just want to depend on your 3458A performing within its published specifications, then the STE9000 cal is probably sufficient. But if you want to track or trend your 3458A by parameter - or to use its calibration test data as correction constants in your processes - then you must have the Standards Lab cal. (The MU of the STE9000 procedure is too high for the supplied test data to be of much value for those purposes.)
> 
> Knowing what I know, I'd rather send my 3458A for Standards Lab cal on a 3 year cal interval, instead of a one year cycle for STE9000 cal. 
> 
> ...apology if you already know this information... ...Just putting out the info in case otherwise. I do know, in the past, confusion over this issue has "tricked" many customers into ordering the wrong 3458A cal based on a misunderstanding of what version calibration they're receiving.
> 
> Best,
> Greg
>