But the vessel is dual wall. Is the lid? Also, if the contents are at 200 C= , does that imply a pressure vessel? Even if the gas above the liquid is not at 200 C, it will still be elevated= beyond the range of "normal" electronics, and certainly beyond the range f= or batteries. And as noted, if the vessel is of stainless steel constructio= n, getting an RF signal out will be near impossible. If modifying the vessel is possible, then a thermowell in the lid and exten= ding to just above the paddles seems to me to be the best approach. If the = paddles are not fully covered then mounting a sensor on the paddles will be= a problem anyway. The Omega RTD unit you linked to earlier seems the best candidate so far (but mounted on the lid with th= e transmitter outside!) Is a 6" probe enough? Good luck Stephen -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of= Sean Breheny Sent: Sunday, 25 March 2018 11:16 AM To: Microcontroller discussion list - Public. Subject: Re: [EE]: Temperature sensing - wireless, short range Do the stirring vanes really extend all the way to the inner wall of the ve= ssel, over the entire height of the vessel? I find it hard to believe that = you couldn't have a temp sensor mounted through the vessel wall which stick= s out a few millimeters into the fluid. On Mar 23, 2018 10:11 PM, "K S" wrote: > > Slip rings would be very noisy though. you could create a board=20 > that spins with the shaft (after the slip rings) to convert the=20 > temperature to digital signal --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .