Gas Sensor Module MQ-7

The MQ-7 module is a gas sensor module specifically designed to detect levels of carbon monoxide (CO) gas in the environment. The module is mounted on the PCB with TTL pins which makes it very easy to use it with controllers like Arduino,Raspberry PI, ESP etc.
This module is widely used in various applications such as gas leakage detection, industrial safety systems, and environmental monitoring. Here are some key points about the MQ-7 module:

1. Gas Sensing Principle: The MQ-7 module utilizes a semiconductor-based gas sensor that detects carbon monoxide gas. The sensor’s resistance changes in the presence of CO gas, and this change is measured to determine the gas concentration.
2. Operating Voltage: The module typically operates at a specific voltage, commonly 5V, which is supplied through the module’s power pins.
3. Analog Output: The MQ-7 module provides an analog output signal that varies based on the concentration of CO gas detected. This analog output can be connected to an analog-to-digital converter (ADC) or microcontroller to measure and interpret the gas concentration.
4. Preheat Time: The MQ-7 module requires a preheat time to stabilize the sensor before accurate readings can be obtained. This preheat time is typically a few minutes and may vary depending on the specific module and environmental conditions.
5. Calibration: To ensure accurate measurements, the MQ-7 module may require calibration. This calibration process involves exposing the sensor to a known concentration of CO gas and adjusting the measurement accordingly.
6. Sensitivity and Range: The MQ-7 module has a specific sensitivity to carbon monoxide gas, and its range of detection typically varies from a few parts per million (ppm) up to a few hundred parts per million. The module’s datasheet provides information on the specific sensitivity and range for accurate interpretation of gas concentrations.