What is resonant impedance?

[chipwitch]

I bought some of these generic piezo elements on ebay.  http://www.ebay.com/itm/121270884189?var=420233429010&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

The specs at the bottom indicate "Resonant Impedance" at 200W?  Google is showing a bunch of hits that I don't think is the same thing.  The "watt" units was throwing me.  I would think it should be Ohms?

[Dago]

The omega symbol '?' often gets converted to 'W' due to re-encoding characters to a different encoding.

[IanB]

The lower case Greek letter omega looks like a curly "w". Since the ohms symbol is an upper case omega, it sometimes happens that uppercase "W" is used to represent uppercase "Omega":



It's a bit odd, since omega is really a letter "o", not a letter "w". But using uppercase "O" would lead to confusion with zero, so "W" is used to avoid that.

[chipwitch]

Ah... yes.. now it makes perfect sense.  Thank you.