FEATURES: * High sensitivity to CH4，Natural gas. * Small sensitivity to alcohol, smoke. * Fast response . * Stable and long life * Simple drive circuit APPLICATION: They are used in gas leakage detecting equipment in family and industry, are suitable for detecting of CH4,Natural gas.LNG, avoid the noise of alcohol and cooking fumes and cigarette smoke.

Sensitive material of MQ-4 gas sensor is SnO2, which with lower conductivity in clean air. When the target combustible gas exist the sensors conductivity increases higher along with the gas concentration rising. MQ-4 gas sensor has high sensitivity to Natural gas, Methane and could be used to detect both Methane and Propane. The sensor could be used to detect different combustible gas especially Methane, its low cost and suitable for different application. Features: -High sensitivity to Combustible gas in wide range. -High sensitivity to Natural gas Methane, Coal gas, CO etc gas. -Fast response. -Wide detection range. -Stable performance, long life, low cost. -Simple drive circuit.

Features: -With relay output, this module is used to detect the humidity and control related the device power directly. -This product make use of HR202 humidity sensor. -The comparator outputs drive relays directly. It connects to 220V AC or other devices. -With leads, sensor interface can be installed with pin. -It's easy to install with 4 0.3cm fixing bolt hole. -When ambient humidity exceeds the setting threshold value the relay sucks and shuts, what's more, the common terminal connects to the start. -If the ambient humidity below the setting threshold value, the situation will be counter. -Common, normally open and normally closed the three ports are equivalent to a dual-control switch. -When the relay coil is electrified, the common will connect to the normally open, otherwise, the common will connect to normally closed.