Electronics Question

[Munroast]

This all relates to an electronic outdoor temperature gauge and extending the wire to the probe. It would appear that the probe is a 4k7 thermister.
At 0°c it has a resistance of 15.28K
at 25°c 4.7k
at 100°C 318 ohms

I have just calculated 100m of bell wire (200m of wire in total) to have a resistance of 13.7 ohms. Would I be correct in thinking that if I used all 100m, that below 25c the diff would be negligible . ie at 25°C the resistance would have only altered by 0.3% (less than 0.1°)
Or is there some other considerations I should be taking into account ?

I am assuming that two resistors in series you would just add together ?

 

[Burnerman]

That amount of resistance can be safely ignored when used in your weather station.....and if you have two resistances in series, you add them together to give a total.
John

 

[EightyTwo]

Sounds good to me, too. If you're going to run cable outside, make sure that the insulation material is UV resistant (like PE...).