Design and Development of a Low-cost Embedded Sensor Device for Real-time Environmental/Thermal Monitoring
Keywords:
Heat index, Heat wave, Psychrometric properties, Specific humidity, Thermal comfortAbstract
The increasing frequency and intensity of heat waves, exacerbated by climate change and local factors in tropical regions such as the Niger Delta, pose serious risks to human health, agriculture, and infrastructure. This study develops a low-cost, portable heat wave meter to measure and display key psychrometric properties of air—temperature, relative humidity, specific humidity, enthalpy, and heat index—for real-time assessment of heat stress conditions. The device utilizes a DHT11 temperature and humidity sensor, an Arduino Uno microcontroller, a 16×4 I2C LCD, and is powered by a 9V battery. Temperature (30–34°C) and relative humidity (55–63%) data were collected and processed to derive specific humidity, enthalpy, and heat index using the NOAA regression formula. SolidWorks was used to model the device for manufacturability. Results showed enthalpy increasing from 67.73 kJ/kg (30°C, 55% RH) to 85.28 kJ/kg (34°C, 63% RH), demonstrating higher energy storage in moist air. Heat index rose sharply from 34.8 to 43.4°C, with values exceeding 40°C triggering “Danger” alerts consistent with NOAA categories, indicating significant heat stress risk. Specific humidity increased from 0.0147 to 0.0211 kg/kg, reflecting elevated moisture capacity at higher temperatures. The meter effectively provides real-time monitoring and alerting for dangerous heat conditions, offering valuable insights for thermal comfort and heat stress evaluation in resource-limited settings. Recommendations include the addition of data logging and the adoption of a rechargeable battery.
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