Your question is indeed crucial for safety in the chemical industry. Gas detector readings are generally reliable if the devices are properly maintained and calibrated. Calibration should be done regularly and as per the manufacturer’s instructions. It is also important to use them correctly, considering factors such as the location and the type of gas they are designed to detect.
However, like any tool, they’re not infallible. Always cross-verify critical readings and have a contingency plan in place.
Remember, a gas detector is just one part of a comprehensive safety system.