exhaust temperature pyrometer

I’ve been reading up on pyrometers, installing one on my Truck, I called Isso, tech was very informative. Basically, the probe should be within 6” of the exhaust pipe flange, on turbo when mounting in the exhaust pipe. Supposedly there’s roughly 200 degrees difference between readings if mounted in exhaust manifold, vs. exhaust pipe.So 900, would roughly equate to 1100 degrees, pre turbo. Harness needs to be between 6’ and 15’, for accuracy, and best if made by Same brand as the guage. Isso was great, quick precise answers.

 

I would question that.
My observation was about a 600º to 700º difference from the manifold to behind the turbo.
From 900º behind the turbo to 1500º or 1600º in the manifold.
Mind you that was the late 70's.

A lesson learned about sensors in manifolds, the tip is more likely to melt off and go through your turbo, which is what mine did, ouch.