Font size of text in a pdf with Preview

I've a pdf (generated by LaTeX) and Preview Version 7.0 (826.4). I'd like to select some text and have Preview tell me its size.

Can this be done? If so, how please. If not, can Adobe Reader XI do it?

Thanks

Arthur

PS. Strange that "identify product" selector below a) doesn't contain Preview, and b) isn't alphabetical