From kls Fri May 29 02:44:08 1998 Path: bounce-back Newsgroups: sci.aeronautics.airliners Date: 29 May 98 02:44:08 From: "Chris Hall" Subject: Re: Rosemount Probe References: Message-ID: Approved: kls@ohare.Chicago.COM Sender: kls@ohare.Chicago.COM Yves E. Hoebeke wrote in message ... >I would like to understand how the Rosemount probe can deliver accurate TAT >info while it's heating element (anti-ice) is switched on. > >I understand from my textbooks that this will not interfere with its >measurement accuracy, but I do not understand how. Easy, Yves. The mast heating element is separate to the temperature measuring element. The TAT figure is calculated by measuring the electrical resistance of a coil of wire in an almost stalled airstream inside the probe. The mast heating element is well away from this airstream, and the heat in the mast is taken away by the outside airflow pretty fast. Chris Hall.