Hi Ken and the group,
When building up the spectrum over many fast impulse events, like ESD,
I suspect the analyzer display is not calibrated as an event that is
over in 5 nanoseconds or less (fast part of ESD) is not around long
enough for the analyzer to "lock on" accurately to the signal. The
envelope/shape of the plot can give an idea of the bandwidth, but the
amplitude displayed is not likely accurate in most cases.
Doug
On Thu, 12 May 2016 07:54:51 -0600, Ken Wyatt wrote:
Hi Li Di,
Both Ed and Cortland gave you some good advice. Capturing the frequency
content of a transient signal is main “claim to fame” of the
real-time (RT) spectrum analyzer and you might want to refer to the new
guide we published recently, “Real-Time” Spectrum Analyzer Mini
Guide”, which may be downloaded here:
http://www.interferencetechnology.com (click on the guide in the upper
left corner of our home page)
RT analyzers are the ideal solution to capturing transient events
within their RT bandwidth, which can range from 27 to 500 MHz,
typically. However, for a spark event, as you’re describing, the
energy will greatly exceed the real-time bandwidth of any RT analyzer
I’m aware of. As Ed suggests, I’ve managed to capture repeated
events using the “max hold” feature of a swept analyzer, but you
must let the spectral envelope build up gradually. This may be good
enough for your purposes and I would expect the bulk of the energy to
extend out to 2-3 GHz.
The other alternative, as Cortland suggests is to use a fast
oscilloscope of at least 6 GHz bandwidth to capture the transient and
convert to frequency via the FFT feature. I’ve captured spark events
successfully with this method, but you’ll have to manually figure out
the gains and losses in the system to calculate the actual E-field
generated from the spark.
One other possible alternative would be to use one of the newer
FFT-based spectrum analyzers that can perform the capture with very
little “dead time”.
Cheers, Ken_______________________
I'm here to help you succeed! Feel free to call or email with any
questions related to EMC or EMI troubleshooting - at no obligation.
I'm always happy to help!
Kenneth Wyatt
Wyatt Technical Services LLC
56 Aspen Dr.
Woodland Park, CO 80863
Phone: (719) 310-5418
Email Me! | Web Site | Blog
The EMC Blog (EDN)
Subscribe to Newsletter
Connect with me on LinkedIn
On May 11, 2016, at 11:52 PM, Li Di wrote:
Hello All,
I need to measure the transient radiation emission from a big
industrial system. There is a discharg between its two electrodes with
high voltage difference. My client wants to measure the transient
interference at their facility. I plan to use spectrum analyzer and
antenna (or near field probe). But the scan time of some spectrum
analyzers is long. It is not easy to catch the inteference. Could
anyone give me some advice? Thank you very much.
Best regards,
-------------------------
Li Di
Conorth Technologies Co., Ltd.
-----------------------------------
Address: Room 212, Building C, No.15 Baiziwan Road, Chaoyang District, Beijing
Tel (Fax): 0086-10-60530811 (Office)
Mobile: 0086-13701332910
Email: li...@conorthtech.com
Website: www.conorthtech.com
------------------------------------------
-
----------------------------------------------------------------
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
All emc-pstc postings are archived and searchable on the web
at: http://www.ieee-pses.org/emc-pstc.html
Attachments are not permitted but the IEEE PSES Online Communities site
at http://product-compliance.oc.ieee.org/ can be used for graphics
(in well-used formats), large files, etc.
Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to
unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html
For help, send mail to the list administrators:
Scott Douglas
Mike Cantwell
For policy questions, send mail to:
Jim Bacher
David Heald
-
----------------------------------------------------------------
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 <emc-p...@ieee.org>
All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html
Attachments are not permitted but the IEEE PSES Online Communities site
at http://product-compliance.oc.ieee.org/ can be used for graphics (in
well-used formats), large files, etc.
Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to
unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html
For help, send mail to the list administrators:
Scott Douglas <sdoug...@ieee.org>
Mike Cantwell <mcantw...@ieee.org>
For policy questions, send mail to:
Jim Bacher <j.bac...@ieee.org>
David Heald <dhe...@gmail.com>
-
----------------------------------------------------------------
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 <emc-p...@ieee.org>
All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html
Attachments are not permitted but the IEEE PSES Online Communities site at
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
formats), large files, etc.
Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html
For help, send mail to the list administrators:
Scott Douglas <sdoug...@ieee.org>
Mike Cantwell <mcantw...@ieee.org>
For policy questions, send mail to:
Jim Bacher: <j.bac...@ieee.org>
David Heald: <dhe...@gmail.com>
