The more interesting Part for Professionals would be the long term aspects of the calibration values, the reliability in general, the reputation, the availability of pare parts, Robustness etc.
Dave didn't calibrate them. As far as I could tell he was just checking them for consistency. But he didn't make any adjustments.
I do not have the software cal adjustment procedure.
So are these meters now not brand new, but rather slightly used.No, they are not used ! They have been calibrated by Dave personally. I hope he gives out a EEVblog Cal certificate with this limited series meter
Dave didn't calibrate them. As far as I could tell he was just checking them for consistency. But he didn't make any adjustments.
I was just using the term calibration in the same sense Dave did when he said "I haven't asked Brymen how they actually calibrate these things." or "They can actually software calibrate these things".
So are these meters now not brand new, but rather slightly used.No, they are not used ! They have been calibrated by Dave personally. I hope he gives out a EEVblog Cal certificate with this limited series meter
Dave didn't calibrate them. As far as I could tell he was just checking them for consistency. But he didn't make any adjustments.
Haven't you kept up with the many 'calibration' Vs 'adjustment' threads around here. There are two camps of opinion:
Camp 1. Calibration is not adjustment. Calibration is comparing with 'provable' testing standards and equipment and stating the differences seen on the various ranges and functions of the device being 'calibrated' and printing a report and/or sticker for the tested item.
Camp 2. What camp 1 calls calibration we call that verification or certification only. We feel a calibration is when adjustments are made, either open/closed/firmware/trim pots/whatever, to align the device being checked to match the 'provable' standards and equipment stated values. A published report should state the 'as found readings' and the 'post calibration/adjustment' readings.
Dave in one of his videos stated that "calibration is not adjustment", so I guess he is a firm camp 1 member. Or perhaps he is just stating what it means to the firms he has dealt with. Pick your camp I guess.
I was just using the term calibration in the same sense Dave did when he said "I haven't asked Brymen how they actually calibrate these things." or "They can actually software calibrate these things".
My Websters English dictionary says that calibration means checking AND adjusting a piece of test equipment.
News to me. Ive never done it, but for most people I think they would expect a device to be corrected if out.
My Websters English dictionary says that calibration means checking AND adjusting a piece of test equipment.
This is not something you want to trust the dictionary on.
At most companies running a proper quality system and take calibration seriously, if you sent a bit of gear for "calibration" and asked them to perform a calibration adjustment, then you'll get booted out the door pretty quick, or slapped over the head. Why? because you just ruined the calibration and drift history of that instrument.
QuoteI've read that argument before but don't understand what is being 'ruined'? As long as they record the 'as found before adjustment' readings and the 'after adjustment' readings what data is lost? You still have the drift value from the prior calibration interval so one knows the drift between those two dates. As a user I'm not interested in tracking unadjusted calibration drift over many years but rather from the last 6 month or yearly calibration interval.
When you send something to a cal lab "for calibration" they will just measure it and give you a report. They will only adjust it if you ask them to.QuoteAnd of course pay them some amount above their 'normal calibration' quotation I would have no issue with this subject if the calibration services would just quote two types of service, validation (at a lower cost) and calibration (at higher costs) so one clearly knows what they are getting for their money. Can anyone show us a DMM manufacture that discusses calibration procedures in their owners manual that doesn't involve some kind of hardware or software 'adjustment' ?
I know this sounds a bit ridiculous to Joe Average electronics enthusiast
This chapter of the Service Manual provides performance tests that can be used at any
time to verify Fluke 45 operation within published specifications. A complete calibration
procedure is also included. The performance test and, if necessary, the calibration
procedure can be performed periodically and after service or repair.
I've read that argument before but don't understand what is being 'ruined'?
As long as they record the 'as found before adjustment' readings and the 'after adjustment' readings what data is lost? You still have the drift value from the prior calibration interval so one knows the drift between those two dates. As a user I'm not interested in tracking unadjusted calibration drift over many years but rather from the last 6 month or yearly calibration interval.
And of course pay them some amount above their 'normal calibration' quotation I would have no issue with this subject if the calibration services would just quote two types of service, validation (at a lower cost) and calibration (at higher costs) so one clearly knows what they are getting for their money.
They quote whatever you ask them to quote.
They'll tweak the EEpots nude whilst listening to wale songs if you pay them enough money.
And also I am curious what will happen if you connect all of them in series for a current measurement? World's largest chain current mesurement
Burden voltage demonstration.
Would be an interesting one to do, actually. We can calculate the answer - but a graphic picture might make more of an impressionon some viewers.....
(0.3% isn't a very good spec for something with a 22000-count chipset that displays 5 digits on screen)
(0.3% isn't a very good spec for something with a 22000-count chipset that displays 5 digits on screen)
Agreed, but if other conditions hold it might just be useful.
A company I once worked for sold a very expensive attenuation meter with a 0.1dB accuracy and a 0.001dB stability and repeatability. The stability was important since it was used to detect small changes in attenuation over the course of a week or so.