This is my first time posting in this section, and to be frank, I know nothing about it (please help).
I am trying to build an arduino rain sensor, and I want it to be accurate. This means I must have a heater to evaporate the rain so the arduino doesn't think it is raining 2 hours after the rain has passed, because in England there are lot's of showers.=D. I have no clue how you get an arduino to run a heater, and would be very grateful for your help.
To accurate measure if it is raining, perhaps you could use a rain measering device from a weather station.
This method is not very reliable : electronic rain detector.... test 1 - YouTube
The sensor could get dirty, causing it to think that it is raining.
There is a lot information about rain sensor, like this one: Arduino Forum
Edit: I think I misunderstood your question. Your goal is to measure the rain, and not to turn on a heater ? So you only want to detect if it is raining or not, or do you want to measure the amount of rain ?
I want to know just if it raining or not, I have already worked out how to do this, but it is not accurate, so i wanted to know how to turn a heater on when it is raining, which will evapourate the water so if it is not raining it will be dry, and not still wet from the rain.