Design and Calibration of a Low-Cost, 3D-Printed, IoT-Enabled NonContact Infrared Thermometer with Wireless Feedback for Remote Health Monitoring

Abstract

Infrared thermometers are non-contact devices that measure temperature by detecting infrared radiation emitted from an object’s surface. These devices offer rapid, accurate readings, but challenges such as environmental interference and calibration issues persist. The study aimed to design and calibrate a low-cost 3D printed, IoT-enabled non-contact infrared thermometer with wireless feedback. The main components used to develop the device include the MLX90614 infrared temperature sensor for accurate non-contact temperature readings, an ESP32 microcontroller for data processing and wireless connectivity, and a SIM800L GSM module enabling SMS notifications. The ESP32 was programmed using the C programming language in Arduino IDE. The thermometer’s casing was developed using 3D printing technology based on a user-centered approach that enhances ergonomics and durability while significantly reducing production costs. Comparative analysis of the 3D printed infrared thermometer and a standard commercial infrared thermometer before and after calibration showed a significant reduction in Root Mean Squared Error (RMSE) from 2.89 °C to 0.21 °C. The Mean Absolute Error (MAE) reduced significantly from 2.8 °C before calibration to 0.17 °C after calibration. The results revealed comparable performance of both IR thermometers. The study effectively developed a prototype 3D printed infrared thermometer that combines contactless sensing and wireless transmission of temperature data through SMS and email.