What does a Photoionization Detector (PID) measure?

A Photoionization Detector (PID) is an instrument specifically designed to measure the concentration of volatile organic compounds (VOCs) and other gases in the air. It operates by using ultraviolet light to ionize the molecules of the target substances. When the substances are ionized, they produce charged particles that the PID can detect, allowing for a quantitative measurement of their concentration.

PIDs are particularly effective in detecting low levels of VOCs in various environments, making them valuable tools in environmental monitoring, industrial hygiene, and safety assessments. The ability of the PID to identify and quantify these substances is crucial for assessing air quality and ensuring compliance with health and safety standards.

The other options refer to different types of measurements: water turbidity levels, electrical conductivity of water, and groundwater temperature are parameters measured by different instruments, not by a PID. Each of these parameters requires different methods and technologies, which distinguishes them from the specific function of a Photoionization Detector.