OAT is measured by a tiny 1/4" diameter sensor that's located just inside the cooling plenum duct, maybe 2" in from the front of the plane. I doesn't react instantly, and since the plane was on the ground a couple of hours from the previous flight to my father's farm and it was warm when the plane was started, it gradually dropped after engine start. If I remember correctly, the OAT was really about 70F degrees, but it never had a chance to get there. That's a sensor that normally doesn't need to react quickly, so no biggie. I have another sensor stuck under one of the carb's regulator screws to monitor temperature right at the outside of the carb. That's my "under the cowl" temp sensor.
Mark Langford ML at N56ML.com website at http://www.N56ML.com --------------------------------------------------------
