How do you measure Sin?

(having to back-blip this one due to problems uploading to Blip last night)

...use a Sin-o-meter!

As part of the 'moving-stuff-about-after-gaining-a-new-room' initiative, I was doing some tidying and came across my voltmeter. Along with another box of stuff, it was destined for the loft, for now.

I knew it measured Voltage, Current and Resistance, but hadn't noticed what else...