Hi all, my apologies if this has been addressed and I missed it. I was looking at http://www.instructables.com/id/Waterproof-a-LM35-Temperature-Sensor/ - an instructable to waterproof an LM35 sensor. On step 2 they say to put a 10k resistor inline on the Vout pin "to stablize the signal for the length of cable." I don't really know what that means or if I will need it. I'm not sure what I'm going to use for cable at this point but I don't expect my cable run between the Arduino and my LM34 to be longer than 2 feet. If anyone could shed any light on this, I'd appreciate it. Thanks!
Shielded cables are highly capacitive and the LM35 doesn't like driving into capacitive loads. The 10k resistor would isolate the LM35 from the capacitance of the cable.
If you're just using a plain wire (no shield) of only 2 feet, I don't think you need the resistor. The National LM35 datasheet has lots of good application information on maintaining accuracy over long cables and other conditions. Worth a read.