I have been puzzled by my carb temperature. Before engine start, it shows the OAT. However as soon as engine starts, it temperature began to raise. In a few minutes it stopped at 127 degree. When OAT is below 30 degree, it does not reach 127 degree. Early on I talked to Sandy at GRT (my EIS vendor) and she sent me another sensor. The end result is exact the same. I settle with what I have. Recently there is a discussion on where to install carb sensor on VAF. I showed my pictures and mentioned the problem. Someone said that 127 degree is just wrong. Well, today I found my old sensor and did a simple test. I basically connected the output of the sensor to a ohm meter and heat the sensor body up. The resistance value reduces when the sensor is heated. Well, that pretty much proved that the sensor is measuring the carb body temperature. The venturi where carb ice may form is a distance from the sensor and the temperature may differ. One really can not rely on the sensor reading to prevent carb ice.