Detector Rankings Tool

 

One of the more advanced capabilities of Detect3D is the Detector Rankings Tool. The tool quickly disables then enables each detector in the project. While the device is disabled the change in coverage results for 1ooN and 2ooN are recorded before continuing to the next device. Once complete, the rankings tool then lists and ranks each detector in order based on a weighted average of the 1ooN and 2ooN changes in coverage. The higher the deficit the more important that device is to the total analysis. The opposite is then also true, a lower deficit means that if the detector did not exist in the layout, it won't affect coverage of the layout as a whole as much. This information then allows users to remove or re-position the worse performing detectors - which will be done in this example.

 

To open the detector ranking tool:

  1. Click the Detector Ranking button on the tool bar or select Detector Rankings from the Project Menu. Choose Fire Zone: Main Zone from the available options.

  2. After a short calculation the window shown below appears with a table labeling a Best and Worst detector.

     

    Detect3D_Fire_and_Gas_Mapping_Detector_Rankings_Tool

    Tutorial 11 - Figure 05 - Detector Rankings Window

     

  3. The first column shows the 1ooN Deficit, representing how much the 1ooN coverage lowered when each detector was disabled. Similarly, the second column shows the 2ooN deficit. The rank of each is listed in the 3rd and 4th columns, respectively. The 5th column displays the Weighted Rank of the analysis. This weighting is initially set as 1ooN only, meaning the ranking only looks at the 1ooN deficit values, ignoring the 2ooN values. Other options are 2ooN only and 1ooN and 2ooN (an average between the 1ooN and 2ooN ranks). 

  4. Set the Final Ranking Bias to 2ooN only, this will set the Weighted Rank to solely look at the 2ooN rank and ignore the 1ooN rank. Notice how all the detectors have changed positions in their ordering in the table, excluding Flame Detector 04 (the best) and Flame Detector 05 (the worst). The order of the rows in the table is based fully on the second column (2ooN Deficit) of results, as indicated below.

     

    Tutorial 11 - Figure 06 - Rankings window displaying results with a bias for the 2ooN rank of the detectors

     

  5. Now set the Final Ranking Bias as 1ooN and 2ooN, setting the bias to be an average of the 1ooN AND 2ooN ranks. Here Flame Detector 01 is now ranked 2nd best and Flame Detector 06 is ranked 2nd worst with matches with the 1ooN only ranking.

     

    Tutorial 11 - Figure 07 - Rankings window displaying results based only on the 1ooN rank of the detectors

     

  6. Click the checkbox for Show Ranking Labels at the bottom right of the window. This will toggle the visibility of an additional label in the 3D window for each detector indicating its rank as shown in the image below.

 

Detect3D_Fire_and_Gas_Mapping_Detector_Rankings_Tool

Tutorial 11 - Figure 08 - Displaying the ranking labels for the detectors in the analysis

 

In the next section we will start disabling detectors to see the effect on the rankings and coverage results.

 

The rankings tool gives indication on what the coverage will be if a detector is removed from the coverage calculation. As an example, from the images above, we can estimate that disabling Flame Detector 05 (the worst performing detector) will lower the Main Zone's 1ooN coverage by 1.3%, and 2ooN by 3%.

 

Close the rankings window before continuing.