Oh, for sure.....I looked up the original listing & this thing is perfect for temp & voltage monitoring. The temp guage goes up to 150C it looks like so yeah, that's perfect for a heatsink monitor.....you can file down the cylinder on the end to a flat blade & drill a hole into the end to mount to the sink, possibly. Would take some elbow grease but what a nice mod to make it even more useful. Also, you can put the voltage leads on any DC circuit you wanted to monitor, not just mains....might be useful in avoiding a cap failure if you know what to look for...
So if your juice is too low or your IC's are too hot, BAM!! You can have that info at your fingertips....
Cpl