Originally Posted by Blauhung
Be careful with those sensors as the operational temp range appears to top out at 80C or 176F, this is only slightly over mashout temp. They probably won't melt, but depending on the plastic used it might start to leach out chemicals into your beer. These would work nicely for fly sparging though assuming they are calibrated properly. As for where on the line you place them as long as the sensor is mounted somewhere and not loose it doesn't matter where in the flow path it is mounted as it will be the same. If you use them on the Boil kettle, they will have to be placed after your chiller as 100C might actually melt them.
I'm actually using them in my kegerator, not for brewing. I'm attaching them to the beer line to keep an output of how much beer is left in my cornys. I'll also have the beer name, style, and ABV/IBU on there as well.