I have no idea if this includes that character, but you might want to check out:

http://www.p22.com/products/gdandt.html

Code2000 by James Kass

On Windows...

Serif - Cambria Math
Sans - Segoe UI Symbol

thanks.

GDandT doesn't have it, but it would be a good font to have included it
I haven't looked at Code2000 but I will when I get home.

I thought Sego was a bundled Windows font, but I don't have it. Hmm...

the symbol is in Cambia Math alright, but it is out of proportion with the rest of the font. With the symbol at 9 points it is the same saze as the rest of the font at 11 points. I also think the symbol looks kind of goofy with serifs, but maybe that's just me.

I took the time to do what I could have done bearlier and scrolled though all the fonts on this computer.

Here's what I found:

Arial Unicode has a serifed centre-line symbol (why serifs?)
Cambria Math
Isocp (CAD font*)
Isoteur (CAD font)
Roman S (a monoline serif CAD font made of multiple line segments )
Simplex (sans serif CAD font made of multiple line segments )

Palitino shows a nice little spiral for that glyph.

This is for dimensions and specs on shop drawings, for which I perfer a sans serif. I tend to use Calibri.

Segoe UI Symbol comes with Windows 7. Sorry I failed to mention that.

Using UnicodeChecker on the Mac, I find this symbol in Apple Symbol (serifs), Arial Unicode MS (oddly, also with serifs -- don't the MS type designers know a serif from a sans?), Code2000, Geneva (finally as a sans!), and ... in Helvetica!

Unfortunately, since you are on Windows: this Helvetica is an Apple dfont that came with the system: "© 1990-2006 Apple Computer Inc. © 1981 Linotype AG © 1990-91 Type Solutions Inc.", v. 6.1d18e1.

>I find this symbol in Apple Symbol (serifs),

I'd guess the book originally had a serif design and the designers just copied it? Current code-charts show a sans design.