How large should the discs be that indicate the service status of the sprinkler systems?

The correct size for the discs indicating the service status of sprinklers is typically 8-9 inches. This size is effective because it ensures that the discs are large enough to be easily visible from a distance, which is crucial for maintenance personnel and the general public to quickly assess the service status of the sprinkler system. Being easily readable helps to convey important information about whether the system is operational, under maintenance, or out of service.

In practice, using discs that are too small could lead to visibility issues, as text may become difficult to read from a distance, potentially risking confusion during an emergency or maintenance situation. Conversely, discs that are excessively large might create unnecessary clutter around the sprinkler system or be impractical for space-constrained environments. Thus, an 8-9 inch diameter strikes a suitable balance between visibility and practicality.