Tutorial 13 - Flame Detection Box Method

 

Detect3D Fire Box Method Description

 

This tutorial will go over the box method for flame detector positioning.

 

The box method provides an alternative technique for calculating coverage. Instead of the zone being filled with points in space, it is instead filled with boxes of a set size. The boxes loosely represent the size of fire you want to detect. The coverage of the box is determined by the area of the faces that are visible to the detector. Just like for the point method, the box may be out of range of the detector or obscured by CAD objects in between the detector and the box.

 

The amount of the box visible to the detector determines its coverage. In the default box method, the amount of the box required to be visible to the detector depends on distance from the detector. It is assumed that 100% of the box must be visible at the detector’s maximum range, but this number reduces according to the inverse square law. Thus, at half the maximum range of the detector, only 25% of the box is required to be visible as the radiation intensity is four times higher.

 

The advantage of the box method is that it reduces very small areas of zero coverage that can appear with the point method. For example, if the target fire size is 1ft x 1ft, then zero coverage areas in the point method that are 0.1 ft (as an example) are not really zero coverage because the fire is larger than that region. By contrast, these very small zero coverage areas would be eliminated by the box method.

 

In general, coverage is improved by using the box method, however there are cases where the reverse is true.

 

If you have any questions about the box method, please email us at info@insightnumerics.com

 

 

Learning objects for this tutorial include how to:

  • Apply the box method to a zone in Detect3D

  • View resulting coverage results from the box method.

  • Add and view isovolumes for zero coverage areas when using the box method

 

Files used in this tutorial:

 

Contents of Tutorial 13: