Detection Activation Calculator

This calculator uses to Alpert's corrolation to determine the activation time of a detector or sprinkler.

The following image shows how the radius distance is measured.

Fire growth

Radius m

Height m

Response Time Index (RTI) m0.5 s0.5

Ambient temperature ^oC

Detector activation temperature ^oC

Inputs		Outputs
Fire growth		Ceiling jet temperature
Radius		Ceiling jet velocity
Height		Heat Release Rate (HRR)
Response Time Index (RTI)		Time
Ambient temperature
Detector activation temperature