Good CO Sensitivity
Designed for carbon monoxide detection across a 10–500 ppm range.
MQ-7B Semiconductor Carbon Monoxide Gas Sensor
The MQ-7B is a SnO₂ semiconductor carbon monoxide sensor using cyclic high- and low-temperature operation. It detects CO during the 1.5 V low-temperature phase and cleans adsorbed gases during the 5 V high-temperature phase.
BrandWinsen
Sensing PrincipleSemiconductor
Target GasCO
Product TypeSemiconductor CO Gas Sensor
Gas Sensing for OEM Integration
Product Overview
A cost-effective semiconductor CO sensor for domestic, industrial and portable carbon monoxide alarms.
Sensor conductivity increases as carbon monoxide concentration rises and can be converted into a concentration-related voltage using a simple external circuit.
Its 10–500 ppm range, long life and mature cyclic-heating method make it suitable for high-volume alarm products.
Designed for Reliable Integration
Key Features
Cyclic Heater Operation
Uses 90 seconds at low temperature for CO detection and 60 seconds at high temperature for cleaning.
Simple Drive Circuit
Conductivity changes can be measured through a basic load-resistor circuit.
Low Sensor Cost
Suitable for cost-sensitive, high-volume alarm products.
10-Year Life
Official product specification lists a 10-year lifespan.
Standard Through-Hole Package
Uses a familiar Ø16.7 mm plastic-cap package.
Typical Use Cases
Applications
Domestic CO Alarms
Industrial CO Alarms
Portable CO Detectors
Safety Monitoring Equipment
Official Product Parameters
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | MQ-7B |
| Sensor Type | Semiconductor, SnO₂ |
| Standard Encapsulation | Plastic cap |
| Detected Gas | Carbon monoxide (CO) |
| Detection Range | 10–500 ppm |
| Loop Voltage | 5.0±0.1 V DC |
| Heater Voltage | 5.0±0.1 V high temperature; 1.5±0.1 V low temperature |
| Heater Time | 60±1 s high temperature; 90±1 s low temperature |
| Load Resistance | Adjustable |
| Heater Resistance | 30±3 Ω at room temperature |
| Heater Consumption | ≤950 mW |
| Sensitivity | Rs in air / Rs in 150 ppm CO ≥5 |
| Output Voltage | 2.5–4.3 V in 150 ppm CO |
| Concentration Slope | ≤0.6, R300 ppm/R50 ppm CO |
| Standard Test Conditions | 20±2°C; 55±5% RH |
| Preheat Time | At least 48 hours |
| Required Oxygen Content | 21%, not less than 18% |
| Dimensions | Ø16.7 × 9.4 mm |
| Expected Life | 10 years |
Specifications are based on the official Winsen product page or product manual. Confirm the latest datasheet, calibration requirements, communication protocol and mechanical drawing before final product design.
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