Measurement of humidity, humidity sensor, humidity detection, with a relay output, direct power control equipment using high-quality HR202 humidity sensor; the comparator output directly drive the relay, the 220V AC or other equipment; with a potentiometer to adjust temperature detection threshold sensor interface can be arranged needle, with the lead of humidity sensor; The circuit board size: 50x26mm, thickness 19mm, with four 3mm fixing bolt holes, easy to install Contact normally open circuit connection: Functional diagram connection is when the relay does not suck timely ,publicend and normally closed terminal is turned on, the equivalent of switching off, no power control equipment does not work, when the relay pulls in, the public end and normally open turning, equivalent switch is turned on, the device has power to work Contact normally closed circuit connection: Functional diagram connection is when the relay does not suck timely public side and normally closed terminal is turned on, the equivalent of the switch is closed, the circuit is turned on, the device has power to work, when the relay pulls in, the equivalent of switching off the device no electricity does not work Electrical parameters: Power supply voltage: 5VDC (default: 5V ) currents: 150mA The maximum load: 250V 10A AC or 30V 10A DC, less than this power can be used Colour:blue Material:plastic Size:50 x 26mm Package Contents: 1 * humidity sensor with humidity sensitive resistor Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.