OAT Difference Between JPI and Analog Thermometer

[daviddancer99]

I have a JPI EDM 700 with OAT installed. The probe is mounted on the side of the airplane below and just forward of the pilot's window. The old analog thermometer is mounted at the top of the pilot side of the windshield. When on the ground, both match but when I am at altitude, the JPI reads about 10 degrees warmer than the analog thermometer. I have sent the unit back to JPI and it tested fine. I have also replaced the probe on the JPI. Since they both match on the ground I don't really know where to proceed from here as how to determine which one is correct. Any ideas or similar experiences?

 

[ksykes]

 

[skitheo]

 

[kshaw]

 

[Rarebr33d]

 

[Canuck]

 

[cappy48]

 

[djpfinancial]

 

[boyd8885]

 

[cappy48]