Rancang Bangun Sistem Pemantauan Kualitas Udara Berbasis Iot (Internet Of Things) dengan Sensor DHT11 dan Sensor MQ135

Abstract

The application of Occupational Health and Safety principles is very important in laboratory operations, especially in terms of the use of tools and chemicals that can endanger human health. This research aims to design and build an Internet of Things (IoT) based air quality monitoring system using the NodeMCU ESP32 microcontroller. This system is designed to measure air quality parameters such as temperature, humidity ,and concentrations of harmful gases in the Materials Physics Laboratory unit. The developed monitoring system uses 2 sensors, namely the MQ-135 sensor and the DHT 11 sensor. The MQ-135 sensor is a chemical sensor that is sensitive to CO 2 , alcohol, acetone, and others. Meanwhile, the DHT 11 sensor is used to measure temperature and humidity parameters in the room. The Wi-Fi protocol connects These two sensors to the NoduMCU ESP32 microcontroller to send data to the cloud. Data sent to the cloud can be monitored in real-time using blynk cloud which is an Internet of Things (IoT) platform. The result of this research is a Prototype of IoT (Internet of Things) Based Air Quality Monitoring System. The monitoring system measurement graph shows a linear regression pattern for both temperature and humidity measurements with a coefficient of determination of 0.98 and 0.94 respectively. This shows that the DHT 11 sensor used can respond to changes in temperature and humidity that occur in the space in the test box. The coefficient of determination obtained from measuring alcohol content, acetone content and CO 2 content were 0.85, 0.97 and 0.93 respectively. This shows that the system can respond well to changes in the levels of alcohol, acetone and carbon dioxide in the room.