Implementation Of A Real-Time Internet Of Things-Based Air Quality Monitoring Device For Industrial Areas Using The Blynk Platform

Abstract

Air quality in industrial environments is influenced by machine emissions, vehicle traffic, and dust particles, and therefore requires continuous monitoring. This study aims to design, implement, and test an Internet of Things-based air quality monitoring device that displays data in real time. The device was built using an Arduino Mega 2560 microcontroller and an ESP-01 module as the Wi-Fi network connector, with an MQ-7 sensor for carbon monoxide (CO), an MQ-135 sensor for mixed pollutant gases read as carbon dioxide (CO₂), a DHT11 sensor for temperature and humidity, and a DSM501A sensor for dust particles. The measurement results are displayed on a 20×4 LCD and in the Blynk application, while a buzzer and LEDs provide warnings when values exceed the programmed thresholds. Testing was carried out on July 27, 2025, from 12:00 to 15:00 at 30-minute intervals. All readings fell into the good air classification based on the device thresholds, with CO₂ levels of 0.03–0.43 ppm, CO levels of 3.77–4.95 ppm, and dust sensor output of 674–1175. Data were sent to Blynk in real time and are available as historical graphs. For regional context, the Windy map for the same date showed a highest CO of 2470 ppb (2.47 ppm), PM10 of 717 µg/m³, and AQI of 290. The device works well as an initial monitor, but calibration against a reference measuring instrument is still required before its values are compared with quality standards.