This smd module is an all purpose electronic analysis device for detecting condensation if the measured surface moisture value is above the specified limit about 94 rf the zero potential relay contact opens the signal can be used to switch on a dryer or heating appliance for all shs a type sensors the module has a 3 pin socket used to connect the sensor and a 4 pin terminal for the operating voltage and relay output applications cooling surfaces mildew monitors toilets and bathrooms