(3) For fiber grating heat detector and line type multi-point heat detector, their sensors are embedded into a continuous
line (cable) thus their appearance is line type. In practical use, each sensor part detects its ambient temperature change,
therefore the temperature collection mode of such detectors is discrete. However, the composition of their sensor is
essentially different from that of point type heat detector. They are consistent to other line type heat fire detectors.
Consequently, they belong to multi-point line type heat fire detector