<quote> why can't an in-house calibration have as low a MU as one done by an external cal house? </quote>
It comes to, how do you justify your in-house MU numbers even if you use the same instrumentation. Common practice is type B MU analysis. Most cal labs can afford type A analysis which requires extensive time and cost. A cal lab can achieve significantly low MU numbers with type A. With an in-house calibration, you probably won’t have the resources for type A Regards, Deniz From: [email protected] [mailto:[email protected]] On Behalf Of Bob Richards Sent: Friday, August 13, 2010 8:21 AM To: [email protected] Subject: RE: [PSES] Calibration supplier for signal generator with pulse modulation Calibration can be traceable or not to International Standards. As long as MU is taken into account correctly, one can do virtually all calibrations in house, albeit with higher MU then if done external . While I agree that you are probably correct, why can't an in-house calibration have as low a MU as one done by an external cal house? I've gotten obviously incorrect calibration data back from an external cal lab for a current probe once. It was obvious (to me) that they were trying to measure near the noise floor at the low end of the frequency spectrum (10kHz in this case). The data did not follow the manufacturer's typical curve at the low end, and it did not follow their own data from the previous year's calibration. They did not alert us to any problem. I performed an in-house cal on the device and it followed the expected curve. Who has the lower MU in this case? This goes back to how do you quantify MU for the lab personel. Bob R. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]>
