Optical Sensor for UV Radiation

Team members

LiJiasheng, ChenXingjian, LiXuejian

Idea

This project aims to design a photodiode-based sensor to detect UV radiation levels in Singapore. We expect it can be used for monitoring the real-time UV index of the environment. Photodiodes is a type of apparatus which can convert light into an electrical current and are used for light intensity detection.

Setup

UV Photodiode(280-320nm)

Optical Filters

Analog-to-Digital Converter

Temperature Sensor

Measurements

Selecting the Right Photodiode: According to our research, among different types of UV radiation(UVA, UVB, and UVC), UVB is the primary concern for skin damage and vitamin D synthesis, which wavelength is about 280-320 nm; UV-Specific Photodiodes are usually made of silicon carbide (SiC) or gallium nitride (GaN), which have high sensitivity for UV light.

Designing the Detection Circuit: First, we need to design a circuit that can amplify the weak current generated by the photodiode upon UV exposure. We also need optical filters, which help improve accuracy by ensuring only the desired UV light is detected. Finally, we need a Analog-to-Digital Conversion (ADC), since we need to convert the analog signals from your sensor into digital data: most computers only work with digital signals.

Data Processing and Presentation: We need to choose a microcontroller that can process the signals from your ADC, performing necessary calculations to determine the UV index. We also need an LCD display, smartphone app, or website for displaying the UV index in real-time.