Products > Test Equipment
Can I trust this cal cert
grumpydoc:
Found a 2001 for reasonable money with a cal cert and couldn't quite resist.
Not that I need 7.5 digits but it would be nice to get an idea if my motley collection of 2000's and 2015's and were within spec, as well as my KH 522 (about which I've previously posted - alarmingly in 2015).
Now I realise the limitations of a 2001 in this regard - the extra digit not necessarily bringing all that much in the way of extra accuracy, certainly not an order of magnitude as the best range on the 2001 is 25ppm of reading + 2ppm of range compared with the 2000's 30+5 (on the 2V and 10V scales respectively).
7.5 digits is actually new territory for me though - as is external calibration reports. The document provided looks impressive in that it suggests the 2001 is, in fact, an order of magnitude better than spec with an error on the 20V range of around 1PPM.
But it neglects to mention (other than in an opaque fashion) what standards were used, or what their uncertainties are, or when *they* were last calibrated - should I expect this information?
I guess it will be something like a Fluke 5730A - something in the 3.5-2.5PPM range so I can probably take 1PPM with a pinch of salt and assume that the meter is pretty close - certainly within 10PPM but I can't help thinking that, at this level, there should be more information.
Also - the meter thinks that it was last calibrated in 2009, so they didn't actually take it through the cal procedure, should I be worried about that (I suppose they just took it through a calibration check and as it was in spec left it at that).
I've just included the 1st page the rest is basically the same for the other ranges.
J-R:
I agree, it does seem slightly odd. There are 1-2 least significant digits missing as well...
Briefly I had a couple 2001 DMMs to play with and actually they have an 8.5 digit mode that with a good calibration/adjustment, attention to detail and filter settings can be of some use for DCV at least, IMHO. So actually looking at the data provided I would personally get it professionally calibrated/adjusted.
Martin72:
Hi,
--- Quote ---But it neglects to mention (other than in an opaque fashion) what standards were used, or what their uncertainties are, or when *they* were last calibrated - should I expect this information?
--- End quote ---
We are certified under various standards and are regularly audited to ensure that we meet these certifications.
If we were to present such a protocol to the auditor, we would lose all our certificates, including the request to recall all our products that were measured with the device...Fatal. ;)
A calibration record must detail the standards after calibration has been performed.
The calibration laboratory itself has to list its accreditations and finally, of course, the equipment with which the calibration was performed and to which standard it is calibrated and when this calibration expires.
thm_w:
The cal is from 2011(?) any value it has is long gone.
Either send it off to get an up to date cal, or get a voltage/resistance/etc standard thats been cal'd to test it against.
coromonadalix:
fishy
Here at my job we have way more information than this paper, with tester / technician signature, and yes the reference(s) tools are specified not an Sxx gimmick
We have the before CAL and after CAL .....
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