Definition 3.1 – ALARM CONDITION

ü One consideration was the fact that an ALARM SYSTEM might generate ALARM SIGNALS for an ALARM CONDITION when no valid ALARM CONDITION existed (i.e. a FALSE POSITIVE ALARM CONDITION). A second was the issue that non-numerical values or conditions, or the use of an INTELLIGENT ALARM SYSTEM, might be used to determine the presence of an ALARM CONDITION, yet these factors might not have been included in previous definitions of ALARM LIMIT.

ü On this basis, the committee defined ALARM CONDITION as: “state of the ALARM SYSTEM when it has determined that a potential or actual HAZARD exists.” This definition recognizes that the ALARM SYSTEM can be correct or incorrect in its determination. It also indicates that this state will cause the ALARM SYSTEM, if it is enabled, to generate ALARM SIGNALS for the ALARM CONDITION to bring about OPERATOR response or awareness.

ü The committee then defined ALARM LIMIT as: “threshold used by an ALARM SYSTEM to determine an ALARM CONDITION.” The obvious example would be a numerical threshold (such as a threshold for a high heart rate ALARM CONDITION), but some thresholds might be nonnumerical. Non-numerical conditions, such as a switch in the incorrect position, failure of the OPERATOR to enter certain data or the failure of the ALARM SYSTEM, can also cause an ALARM CONDITION. Furthermore, an INTELLIGENT ALARM SYSTEM can be used to determine an ALARM CONDITION, using an algorithm rather than a simple threshold value. Such an algorithm may have multiple inputs, perform logic-based or time-dependent averaging, use intelligent artefact filtering or employ other techniques so that the actual threshold changes over time or in response to other circumstances.