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

2026-03-17T15:29:36+00:00

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.

Keywords: Infrared sensor, Internet of Things, Infrared thermometer, Remote Health Monitoring, and SMS feedback.

Bacterial Detection in Corrosive Media and Assessment of Corrosion Inhibition Efficiency of Novel Paints

2026-03-24T13:15:14+00:00

Anti-corrosive pigments such as zinc chromate, frequently used in paint formulations to combat steel corrosion, are potentially toxic. In this study, the corrosion inhibition properties of eleven water-based paints formulated with novel corrosion inhibitors were compared with a reference conventional paint (2). The paints were applied on galvanized steel (GS) and mild steel (MS). Painted and unpainted [control (C)] steel samples were immersed in corrosive media (1M HCl, 3.5% NaCl, and tap water). Bacterial population and pH of the corrosive media, as well as corrosion rates of immersed samples, were determined over six months. Escherichia coli, Klebsiella sp., Providentia stuartii, Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, P. oleovorans, and Bacillus anthracis were detected in the corrosive media. Bacterial populations ranged from 3.0×10⁴ to 1.00×10⁶, 3.5×10⁴ to 1.80×10⁶, and 3.0×10⁴ to 2.50×10⁶ CFU/mL for acid, 3.5% NaCl, and water with painted MS, respectively. For painted GS, bacteria ranged from 3.0×10⁴ to 9.0×10⁴, 3.2×10⁴ to 7.0×10⁴, and 3.0×10⁴ to 1.20×10⁶ CFU/mL for acid, salt, and water, respectively. The pH decreased for all samples: 2.4 to 0, 6.5 to 1.0, and 7 to 1.6 for acid, salt, and water, respectively. Paints 1, 2, 5, 7, 11, and 12 showed the lowest MS corrosion rate (0.0002 mm/y) in salt, while paint 9 had the lowest GS corrosion rate (0.0002 mm/y) in salt. All samples corroded completely in acid after six months. Paint 9 (MS) achieved the highest inhibition efficiency of 66.66%. The novel paints performed comparably to conventional paints.

Keywords: Corrosion inhibition, bacterial detection, novel paints, mild steel, galvanized steel, inhibition efficiency

Journal of Engineering Research

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

Bacterial Detection in Corrosive Media and Assessment of Corrosion Inhibition Efficiency of Novel Paints