Not only gas is convenient for life in a city, but also being a guarantee for residents to improve their quality of life. For ordinary families, with a gas alarm to protect the safety of family gas is the most appropriate. Household gas alarm is used to detect whether the gas leakage in a home device, generally installed in the family kitchen. When the concentration of fuel gas in the air exceeds the preset value, the alarm will be triggered and the sound and light alarm signal will be sent. If connected to the alarm host and the alarm center, the network can also alarm, and at the same time, the gas valve will be automatically closed and the air exhaust device will be opened to ensure the safety of the life and property of personnel. The domestic gas alarm mainly adopts semiconductor, planar semiconductor, catalysis and MEMS sensors as detecting elements. At present, the domestic products occupy the mainstream market with the measurement range of 0-10000ppm and 100% LEL. Semiconductor and catalytic components are low cost, easy to develop, and widely used in domestic gas alarms. MEMS gas sensor is used in the market due to its small size, low power consumption and easy integration.

Sensor recommended:

Technical specifications：

（1）Media: C3H8, C4H10

（2）Sealing type: rubber seat, 100 mesh stainless steel cap

（3）Voltage in clean air: V0=0.5~1.5V(depends on the loading)

（4）Voltage in calibration gas : V1＞2.5v

（5）Response time: ≤20s

（6）Recovery time:≤30s

（7）Measuring pole voltage: Vc=5v±0.1

（8）Heating pole voltage: Vh=5v±0.1

（9）Load resistor: RL=1K~50k(adjustable)

（10）Working temperature: -10℃---+50℃

（11）Storing temperature: -20℃---+60℃

（12）Relative humidity: <95%

（13）Testing range: 100-10000ppm

（14）Air pressure: 650-800mmHg

（15）Pre-heating time: 24h

Types of sensors that may be used in the environment:

No.	Model	Product name	Detection gas	Detection range	Picture	Application
1	MQ-G4	CH4 sensor	CH4	100-10000PPM		For alarm, monitor or detector of natural gas, liquefied petroleum gas and town gas.
2	MQ-G5	C3H8 sensor	C3H8	100-10000PPM		For alarm, monitor or detector of natural gas, liquefied petroleum gas and town gas.
3	MQ-D4B	CH4 sensor	CH4	300-10000PPM		1. Combustible gas leak monitoring devices and fire/safety detection systems for households, factories, and commercial use 2. Combustible gas leak alarm and gas leak detector.
4	MQ-K4	CH4 sensor	CH4	100-10000PPM		For alarm, monitor or detector of natural gas, liquefied petroleum gas, town gas and H2.
5	MQ-K5	C3H8 sensor	C3H8,C4H10	100-10000PPM		For detecting instruments and monitors of natural gas, liquefied petroleum gas, town gas and so on.
6	ZC25C-1	methane and propane sensor	methane and propane	1% methane:20-50  1% propane:30-70		Can be used to detect the concentration of combustible gases such as natural gas, liquefied gas, coal gas, and alkanes at industrial sites. It can also be used in combustible gas leak alarms, etc
7	ZC25B-1	methane and propane sensor	methane and propane	20% lel methane:15-45  20% lel propane:10-30		It can be used for leakage alarm or concentration detection of natural gas and liquefied gas in the civil field.
8	TX911-A	CH4 sensor	CH4	0-100% LEL		Household gas leak detection