Alat Kontrol Exhaust Fan Otomatis Berbasis Internet of Things Untuk Analisis Tingkat Asam Basa Pada Rancangan Lemaari Asam Sederhana

Abstract

Chemical spills and gas leaks in chemical experiments can cause acid vaporization and other toxic and hazardous chemicals in the room or laboratory. This research aims to design a fume hood with automatic exhaust fan speed regulation, detecting changes in acid concentration in the air, and a real-time monitoring system based on the Internet of Things. The system uses MQ-137, MQ-135, and MQ-8 gas sensors to detect changes in acid concentration as it evaporates in the air. The exhaust fan speed is automatically adjusted using a dimmer driven by a servo motor, controlled by the ESP-32 microcontroller based on the signal from the gas sensor. The test results on a simple fume hood show the gas sensor response to several types of acid and ammonia with a concentration of 100%. The MQ-137 sensor increases from 0 PPM to 50 PPM for nitric and acetic acid, from 0 PPM to 60 PPM for hydrochloric acid, from 0 PPM to 4 PPM for sulfuric acid, and from 0 PPM to 400 PPM for ammonia. The MQ-8 sensor increased from 0 PPM to 349 PPM for nitric acid and from 0 PPM to 39 PPM for sulfuric acid. These results show that the system is able to detect changes in acid concentration well and provide an important safety mechanism to avoid potential hazards.