Receivers have better dynamic range in the presence of strong signals because they have a tuned front end. A receiver can get better frequency accuracy on a wide sweep because there is no quantization error (the frequency resolution is NOT limited by the span divided by some number of "bins" per sweep). A receiver is normally calibrated over its entire frequency range (often using an impulse generator). That technique is unavailable with a wide-open spectrum analyzer. Often a spectrum analyzer is calibrated at a single frequency.
Having said these things does not mean an expensive receiver is always better than a spectrum analyzer. If I am making measurements in a shield room and I need 1% frequency accuracy a spectrum analyzer will do just fine. I think that both a spectrum analyzer and an EMI receiver are way more instrument than you need to measure safety-related field intensities. The levels you are trying to measure are such that you would not need the sensitivity of either of these instruments, and the frequency resolution of even the spectrum analyzer is much better than needed. I realize that you will use these devices because they are around, but if I were interested in safety-related field intensities from an emitter such as a microwave oven or a cell phone a frequency counter and a power density probe would work just fine. is NOT on 9/25/02 2:51 PM, Muriel Bittencourt de Liz at [email protected] wrote: > > Hello Group, > > For EMC measurements (conducted and radiated emissions), electromagnetic > fields measurements (via antennas), what is the difference between using a > EMI Receiver or a Spectrum Analyzer?? > > Some guesses that I've been thinking are: > > - The Receiver is more accurate than the Spectrum Analyzer, so it is more > suitable for EMC measurements that aim to respect the EMC standards. > > - For measuring electromagnetic fields (eg electric field) for safety (human > safety standards for man-made electromagnetic fields, like ICNIRP) the > Receiver is suitable because it can give an accurate value to a particular > frequency that is being studied. > > - The spectrum analyzer is "qualitative", i.e. it gives an idea of how the > spectra measured is distributed in the frequency range. The receiver is > "quantitative", i.e. it gives accurate amplitude for each frequency swept. > > Well, I think this subject is very controversial, and it will generate a lot > of discussions, that will be good for us all. > > Best Regards, > > Muriel B. de Liz > > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > -- Ken Javor EMC Compliance Huntsville, Alabama 256/650-5261 ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
