I have one thermocouple feeding my pyrometer and my water injection controller.
I ran the thermocouple leads to the back of the pyro, like normal. Then I ran additional thermocouple wire from the back of the pyro to the water injection controller.
The good news is that the pyrometer and the WIC read the same values. I don't know if that value is any different from what the real value is, but it isn't too far off... Probably just enough to melt my engine. :drool:
BUT, for some reason the WIC only gets a meaningful reading if the pyro is turned on.
I've seen thermocouple replicators for sale before, I don't know what exact application they're for. My dad says they're for if you have to run really long stretchs of thermocouple wire, like 600+ feet. But he also says that he's never actually used one before.