MQ-137

Description

What it is

The MQ-137 is a semiconductor chemical sensor designed to detect specific gas concentrations in the air.

Features

• Detects benzene
• Detects nitrogen dioxide (NO2)
• SKU: ARD009129
• Price: 36.03 €

What it is for

The MQ-137 is ideal for environmental monitoring projects, such as measuring NO2 concentration in the air. It can be used to build a simple gas concentration monitor. It is compatible with Arduino and other microcontrollers.

Tutorial: How to use MQ-137

The MQ-137 sensor is ideal for measuring nitrogen dioxide (NO2) in the air. Useful for environmental monitoring projects.

What you need

• 1x MQ-137
• 1x Arduino
• 4-pin connections
• 10kΩ resistor

Steps

1. 1. Mount the MQ-137 sensor on a protoboard.
2. 2. Connect the VCC pin to the 5V of the Arduino.
3. 3. Connect the GND pin to the GND of the Arduino.
4. 4. Connect the OUT pin to a digital pin of the Arduino.
5. 5. Connect the AO pin to an analog pin of the Arduino.
6. 6. Connect a 10kΩ resistor between the OUT pin and GND.
7. 7. Upload the following code to the Arduino.
8. 8. Monitor the analog values with an IDE software.

Example code

```cpp
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

Adafruit_BME280 bme;

void setup() {
  Serial.begin(9600);
}

void loop() {
  int sensorValue = analogRead(A0);
  Serial.println(sensorValue);
  delay(1000);
}
```

Mini project

Build a simple NO2 concentration monitor. In 30 minutes, connect the MQ-137 to an Arduino and display the data on a computer.

Common mistakes

• Do not connect the OUT pin directly to VCC without a resistor.
• Forget to check the analog values with an IDE software.
• Connect the GND pin to a power supply different from that of the Arduino.
• Omit checking the datasheet for further details.

Recommended accessories

• Arduino Uno
• USB cable
• Arduino IDE software
• Protoboard

Frequently asked questions

Why doesn’t the sensor work?
Check the connections and the datasheet for further details.

Which gases can it measure?
The MQ-137 sensor primarily measures nitrogen dioxide (NO2).

How long is the sensor’s lifespan?
Check the datasheet for further details.

Can I use the MQ-137 to measure other gases?
The sensor is optimized for nitrogen dioxide (NO2). Check the datasheet for further details.