Originally Posted by Inspector
Jim:
It has been my experience that no two EGT system will read out the same. I have a difference of as much as 50 degrees in certain driving conditions between my SPA and the Attitude readout and much more than that in other conditions. I have a thermocouple for the Attitude that has a fixed depth of penetration into the manifold and therefore cannot be adjusted to the exact center of the exhaust flow through the manifold. On the other hand the SPA can be adjusted to center. With that said I still don't have an exact match. Sometimes they will match but for the most part the difference is noticable. It gets down to which one to believe. In the airplane business the EGT systems are all calibrated to the same length of wireing within the A/C. When an instrument is in the shop the test equipment is the standard by which the instrument is calibrated. Therefore all the systems in a given model of A/C will read within as little as 15 degrees and not more than 25 between positions. I guess what I'm getting at is that most folks only have one gage and who is to say that it is accurate. At a given speed say 60 one may read as much as 100 degrees different from the next guys. Yes, I would say that your plots will be all over the map. I'm probably being to nit picky here but you know me.
Denny