Measurement of humidity using high-quality HR202 humidity sensor; Comparator output directly drives relay for direct power control of equipment; Features potentiometer to adjust humidity detection threshold; Sensor interface with pin header and lead for humidity sensor connection; Circuit board dimensions: 50x26mm, thickness 19mm, with four 3mm mounting holes for easy installation; Relay contact configurations: - Normally open circuit: When relay is not activated, common terminal and normally closed terminal are connected (equivalent to switch off, no power to equipment). When relay is activated, common terminal connects to normally open terminal (equivalent to switch on, equipment powered). - Normally closed circuit: When relay is not activated, common terminal and normally closed terminal are connected (equivalent to switch on, equipment powered). When relay is activated, circuit disconnects (equivalent to switch off, equipment loses power); Electrical specifications: - Power supply: 5VDC - Operating current: 150mA - Maximum load: 250V 10A AC or 30V 10A DC (suitable for loads below these ratings); Color: Blue Material: Plastic Dimensions: 50 x 26mm Package includes: 1 x Humidity sensor module with humidity-sensitive resistor Note: Package includes only the items listed above. Other items not included. Note: Lighting and display differences may cause slight color variation between image and actual item. Measurement tolerance: +/- 1-3cm.