I believe that if you are only looking for "qualitative" testing (i.e. whether or not harmonics exist) and not "quantitative" testing (an actual value of distortion), and you already own an average sensing and a True RMS amp meter, you can determine if harmonics are present.
http://support.fluke.com/find-sales/download/asset/1260362_k_w.pdf Other than that I have rented sophisticated logging analyzers several times and they are not that expensive overall.
http://www.us-instrument.com/ Look at the "Dranetz" products
[This message has been edited by Redsy (edited 03-12-2005).]
