Out of Stock
Price: KSH 600.00
MQ-7 Carbon Monoxide Sensor
An efficient sensor to detect CO concentrations in the air.
Introduction
The MQ-7 Carbon Monoxide (CO) sensor is designed to detect CO concentrations in the air. It operates on the principle of conductivity changes when exposed to CO. Widely used in safety systems, this sensor is a crucial component for detecting toxic gases.
Pinout
The MQ-7 sensor module typically has the following pins:
| Pin | Name | Description |
|---|---|---|
| 1 | VCC | Power supply input (5V). |
| 2 | GND | Ground connection to complete the circuit. |
| 3 | AO | Analog output providing proportional voltage based on CO levels. |
| 4 | DO | Digital output that goes HIGH when CO level crosses a preset threshold. |
Working Principle
The MQ-7 sensor works based on the following principles:
- The sensor contains a SnO2 layer whose conductivity changes in the presence of CO.
- When CO interacts with the sensor, the conductivity increases proportionally to the CO concentration.
- The module outputs an analog voltage that can be read by a microcontroller for concentration measurement.
- The digital output pin signals a HIGH state if the detected CO level exceeds a preset threshold.
Features
The MQ-7 sensor offers the following features:
- Detects CO concentrations ranging from 20 ppm to 2000 ppm.
- Fast response time and high sensitivity.
- Stable performance and long lifespan.
- Operates on a 5V power supply.
- Analog and digital outputs for flexible interfacing.
Applications
The MQ-7 sensor is commonly used in:
- Home and industrial CO detection systems.
- Car exhaust gas monitoring.
- Air quality monitoring systems.
- Safety systems in enclosed environments like parking lots.
- IoT-based environmental monitoring projects.
Calibration and Usage
To ensure accurate CO level detection, the MQ-7 sensor requires calibration:
- Power the sensor and allow it to preheat for 24 hours for the first use.
- Use a clean air environment to set the baseline output voltage.
- Expose the sensor to known CO concentrations to establish response curves for precise calibration.
- Configure the digital threshold using the onboard potentiometer for DO output.
Troubleshooting
Common issues and solutions:
- No response: Check power connections and ensure sufficient preheating time.
- Unstable readings: Avoid placing the sensor in humid or contaminated environments.
- Incorrect threshold trigger: Adjust the potentiometer on the module.
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