I am currently studying Engineering
I need to be able to sence if something is dry rather than damp. I have currently designed a moisture tester and i was wondering what simple thing i can change/add to the circuit to set off an alarm when something is dry rather than moist.

Cheers

 

If you post the cicuit you have designed, members will be able to suggest ways of modifying it.

 

i hope the attached document helps.

 

Just invert the output of the moisture detector. For example, instead of the output being a logic high when wet, it will be a logic high when dry.