What the the distance in between each fire alarm devices for each loop for fire alarm system ?

It is depend on height of roof, but normally a heat detector cover a circle with 5.3m radius and smoke detector cover a circle with 7.5m radius .

SMOKE DETECTOR COVERS A CIRCULAR AREA WITH RADIUS 7.5 METER.THEREFORE DISTANCE BETWEEN TWO SMOKE DETECTORS IS 15 METERS.SIMILARLY RADIUS FOR HEAT DETECTOR IS 5.3 METER AND DISTANCE IS 10.6 METERS.

7.5m for smoke detectors and 5.3 fo hea detector.

The didstance in between each devices is 7 meter , it mens cover 3.5 meter from  right hand side and 3.5 meter from left hsand side when complete the loap  

The distance in between each fire alarm devices is 4 meters as a standerd. It will vary depend up the make and how the device range of covering of arean.

There is no such a requirement calculate distance between two fire alarm system device. Only thing you need is loop length for specified by manufacture and number of devices per loop ( Number of detector per loop / Number of modules per loop )