What is the function of a lockout device?

A lockout device serves a crucial function in ensuring the safety of workers when maintaining or servicing machinery. Specifically, it is designed to prevent the operation of a machine by securing its energy source in a way that can only be released by authorized personnel. This means that once the lockout device is applied, no one can inadvertently start the machine, thus protecting workers from potentially hazardous conditions.

The effectiveness of a lockout device lies in its ability to provide a physical barrier against the release of stored energy or the operation of the machinery during maintenance. This ensures that any maintenance or servicing tasks can be performed without the risk of unexpected machine start-up or movement.

In the context of the other options, while some may mention tools and monitoring devices, they do not fulfill the fundamental safety function that a lockout device provides in preventing machinery from functioning during maintenance activities. The primary purpose of a lockout device is safety, specifically in terms of controlling energy sources, which is critical in any workplace that utilizes machinery.