MQ-4 Natural Gas Methane Sensor Module - Analog and Digital Gas Detection Board

The MQ-4 Module is a semiconductor metal-oxide gas sensor board engineered to detect methane (CH4) and natural gas concentrations in household and industrial environments. Its sensing element consists of an aluminum-oxide ceramic substrate coated with tin dioxide and enclosed in a stainless-steel mesh; when methane contacts the heated sensing layer, the material’s resistance changes in proportion to gas concentration, and the onboard circuit converts this change into an analog voltage. The module covers a detection range of 300 ppm to 10,000 ppm, making it suitable for early-warning leak detection rather than precise analytical measurement. It provides both a digital switching output (DO, TTL 0/1) and an analog output (AO, roughly 0.1–0.3 V in clean air and up to about 4 V at high concentration), so it can drive a relay or feed an ADC input directly. The board operates from a 5 V DC supply and draws approximately 150 mA, and its compact 32 mm × 20 mm × 22 mm footprint allows integration into confined enclosures. With a working temperature range of -20°C to +55°C and humidity tolerance up to 95% RH, this MQ-4 methane sensor module is well-suited to natural gas safety devices, home security systems, and industrial gas detection equipment that require a low-cost, fast-responding CH4 gas sensor.

Application

1. Household natural-gas leak detectors and kitchen safety alarms.
2. Industrial gas detection systems and boiler-room monitoring.
3. Home security installations that trigger alarms or shut-off valves on methane presence.
4. Arduino and microcontroller projects for DIY safety and environmental monitoring.
5. Educational demonstrations of semiconductor gas sensing and threshold detection.

Specifications

1. Model: MQ-4 Module
2. Target gas: Methane (CH4) / natural gas
3. Detection range: 300 ppm to 10,000 ppm
4. Characteristic gas concentration: 5000 ppm methane
5. Sensitivity: R in air / R in gas ≥ 5
6. Sensing material resistance: 1 kΩ–20 kΩ in 5000 ppm methane
7. Response time: ≤10 s
8. Recovery time: ≤30 s
9. Heating resistance: 31 Ω ± 3 Ω
10. Heating current: ≤180 mA
11. Heating power: ≤900 mW
12. Heating voltage: 5.0 V ± 0.2 V
13. Measuring voltage: ≤24 V
14. Module supply voltage: 5 V DC
15. Module current consumption: approximately 150 mA
16. Digital output (DO): TTL 0/1 (0.1 V / 5 V)
17. Analog output (AO): ~0.1–0.3 V in clean air; up to ~4 V at high concentration
18. Operating temperature: -20°C to +55°C
19. Operating humidity: ≤95% RH
20. Dimensions: 32 mm × 20 mm × 22 mm (L × W × H)