At what level does the high-level alarm activate in a mercury system?

In a mercury system, the high-level alarm typically activates at a threshold of 85%. This predetermined level is set to provide an early warning for operators, allowing them to take necessary actions to prevent overflow or other hazardous situations. The selection of the 85% threshold is crucial as it balances the need for safety with operational efficiency by providing a warning before the system reaches critical capacity. This proactive measure ensures that there is sufficient time to address any potential issues that may arise from excessive mercury levels. In contrast, lower activation levels may not provide enough time for effective intervention, while higher levels could lead to unsafe conditions before any alarms could alert the personnel.