What do people use, professionally or at home, to measure Exhaust Gas temps, AFR, and detonation?

Asking out of interest really, no other reason!

We develop diesel engines at work and we usually use, K-Type thermo couples, or PT100's on machine and on test beds, coupled with datalogging equipment and wondered how this differed from rolling roads or people at home messing around in their garage??

Cheers,

Chris