The Winsensor MQ-7 datasheet details specifications, operating principles, and handling guidelines for the semiconductor CO gas sensor.
The MQ-7 is a semiconductor gas sensor that detects carbon monoxide (CO) using a tin dioxide (SnO₂) sensing layer. It operates with a high‑temperature heating cycle (5 V) for cleaning and a low‑temperature cycle (1.5 V) for detection, providing a simple circuit to convert resistance changes into a concentration‑related output signal. Typical applications include home gas‑leak alarms, industrial CO alarms, and portable gas detectors.
Technical specifications include detection range 10‑1000 ppm CO, heating voltage 5.0 V±0.2 V (high) and 1.5 V±0.1 V (low), heating power ≤350 mW, and a surface resistance of 2 kΩ‑20 kΩ at 100 ppm CO. The document also outlines recommended circuit connections, temperature/humidity test conditions, and extensive handling precautions to maintain sensor performance. This manual is written in Chinese.
| Detectable gas | Carbon monoxide (CO) |
|---|---|
| Detection concentration range | 10‑1000 ppm CO |
| Circuit voltage (Vc) | ≤10 V DC |
| Heating voltage (high) | 5.0 V±0.2 V |
| Heating time (high/low) | 60 s±1 s (high), 90 s±1 s (low) |
| Heating resistance (RH) | 31 Ω±3 Ω (room temperature) |
| Surface resistance (Rs) at 100 ppm CO | 2 kΩ‑20 kΩ |
| Sensitivity (S) | Rs(in air)/Rs(100 ppm CO) ≥ 5 |
| Pre‑heat time | ≥48 hours |
It detects carbon monoxide (CO).
It can detect carbon monoxide concentrations from 10 ppm up to 1000 ppm.