What type of safeguarding device senses a worker in a certain area?

Presence sensing devices are specifically designed to detect the presence of a worker or an object in a designated area, often referred to as a "hazardous area" where there could be potential danger. These devices play a critical role in ensuring safety by automatically shutting down equipment or activating safety measures if they sense someone's presence within a predefined zone.

In industrial settings, presence sensing devices may use sensors such as photoelectric, ultrasonic, or capacitive technologies to monitor the area continuously. Their primary function is to prevent accidents by ensuring that machinery or equipment does not operate when a person enters its immediate vicinity, thereby mitigating risks associated with moving parts or hazardous environments.

In contrast, safety guards are physical barriers designed to prevent access to dangerous areas, while lockout devices are used to ensure that machinery is properly shut off and not capable of being started up again until maintenance is completed. Barriers offer physical separation, but do not provide the automated detection capabilities that presence sensing devices do. Hence, presence sensing devices are essential components in a comprehensive safety system, focusing on detecting individuals in designated zones to promote worker safety.