Nobody wants to get a false alarm. They are annoying, time consuming and costly. Hach realizes this and recently added some features to the software of the Event Monitor system to minimize the number of false positives.

What Hach has done to minimize False Positives:


  1. Hach''s Event Detection System (The Event Monitor) functions by utilizing a trigger signal that is compared to a baseline with the exceedence of a threshold level indicating the occurrence of an event. While the baseline is calculated, the threshold of the trigger signal is user-determined: meaning it can be changed to be made more or less sensitive depending on your preferences. Many customers start with a high threshold (less sensitive) and as alarms arise, the operator will investigate and discover the root cause of the alarm. If the operator feels this alarm could re-occur, the event fingerprint is named and stored in the Plant Library, allowing the event monitor to identify the event should it reoccur. It typically takes only a short amount of time to see events start to repeat themselves and no new events are found. After that point, we see customers lower the threshold (making the system more sensitive) and seeing what new alarms are generated. If you can imagine a pool filled with icebergs: after the first set of alarms are taken care of, you lower the water level, exposing new icebergs.
  1. A new feature of the Event Monitor is its "adaptive tuning" feature. Simply click the button to turn this feature "on" or "off". This new tuning function was added to compensate for the noise within a system. Utilizing the new algorithm, the software for the detection system continually adjusts its sensitivity based on recent noise level in the multiple parameter readings. The adjustment helps to compensate for changes in baseline conditions over time. If the parameter readings become noisier, the system reduce sensitivity, and increases its sensitivity should the readings become less noisy. The result is a sensitive system with few false alarms.

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